94 civic fuel electrical problem?
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94 civic fuel electrical problem?
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Fuel electrical 94 civic
replaced fuel pump,main relay and fuel filter -have to wait for undermined time for fuel pump to come on to start car sometimes it will come on immediately after key is in the on position sometimes 15 seconds sometimes 30 seconds and sometimes 10 minutes --with key on just waiting any Ideas?- my changing parts did nothing
Last edited by Reddog74q2; Oct 14, 2012 at 04:42 PM. Reason: it may have confusing and redundant
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Re: 94 civic fuel electrical problem?
I don't have much to go on here....
Do you have to wait for the Check Engine Light to come on, is that the clue when it will start?
If that isn't your clue, then what do you see?
The ECM controls both the main relay (fuel pump) and the CEL.
Do you have to wait for the Check Engine Light to come on, is that the clue when it will start?
If that isn't your clue, then what do you see?
The ECM controls both the main relay (fuel pump) and the CEL.
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No I have to wait for the fuel pump to start ,I can hear it for about 2 seconds ,it stops ,then it will start- I have not noticed what comes on or goes off if anything -I just hear the pump and that's my clue
Last edited by Reddog74q2; Oct 14, 2012 at 10:03 PM. Reason: left out part
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I would probably have a voltmeter on the line that controls the fuel pump side of the main relay from the ECM, watching to see if the ECM is not turning it on. (I know the pump isn't getting turned on when it should, but is it the fault of the ECM or not?)
That ECM is getting old...
Main relay terminal #1, green/yellow wire, fuel pump control. Check wiring diagrams yourself to be sure.
That ECM is getting old...
Main relay terminal #1, green/yellow wire, fuel pump control. Check wiring diagrams yourself to be sure.
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no. 1 terminal is yel/white on mine no. 5 Blk/Yel --both of these have power when key is turned on -these are the only 2 with power with the relay unplugged. I can jump just 5 and 7 and the fuel pump comes on but wont start w/the relay removed
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I don't know what you are looking at (wait, yes I do).
I'd suggest you get a real OE wiring diagram if you are going to dig deep into this.
Do not ever try to argue about terminal numbering on a part or a connector. They are not always consistent (or logical) and can vary among different manufacturers of the same parts.
ALWAYS trust wire colors in a factory diagram and use that alone to determine or verify a connector numbering scheme....(unless someone has hacked into it).
ALWAYS make certain you are using the correct diagram for the car you have before trusting it......(Been there, done that. Oops.)
These are the terminal designations for the main relay on 94 Civic, (all):
1- grn/yel, pump control from ECM
2- blu/wht, from dash fuse 18, hot with engine cranking only
3-blk, ground G101 on the thermostat housing...A good place for corrosion and poor connection.. check this!
4- yel/grn, power out to fuel pump
5-blk/yel from dash fuse 12 or 24 Hot in run or start
6-yel/blk, power out to ECM and injectors, etc.
7-yel/wht from underhood fuse 31 , B+ at all times
ECM supplies a ground to terminal #1 of the main relay to operate the fuel pump when it desires to operate it.
HTH
I'd suggest you get a real OE wiring diagram if you are going to dig deep into this.
Do not ever try to argue about terminal numbering on a part or a connector. They are not always consistent (or logical) and can vary among different manufacturers of the same parts.
ALWAYS trust wire colors in a factory diagram and use that alone to determine or verify a connector numbering scheme....(unless someone has hacked into it).
ALWAYS make certain you are using the correct diagram for the car you have before trusting it......(Been there, done that. Oops.)
These are the terminal designations for the main relay on 94 Civic, (all):
1- grn/yel, pump control from ECM
2- blu/wht, from dash fuse 18, hot with engine cranking only
3-blk, ground G101 on the thermostat housing...A good place for corrosion and poor connection.. check this!
4- yel/grn, power out to fuel pump
5-blk/yel from dash fuse 12 or 24 Hot in run or start
6-yel/blk, power out to ECM and injectors, etc.
7-yel/wht from underhood fuse 31 , B+ at all times
ECM supplies a ground to terminal #1 of the main relay to operate the fuel pump when it desires to operate it.
HTH
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I will check into this info that I find very informative ,but I won't be able to do this till next weekend....I am thanking you for your help and will post at the end of the week....i am thanking God there are people like you ~thanks again~ Danny
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Don't hate on me if you figure out it needs an ECM though.
I see you found where to change your user profile....I like this:
"You can't judge a man's cover ,by how many times he's been booked!"
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Believe me I am not gonna hate on you ....I like the way you troubleshoot.... I don't have forever to find all the problems that extensive trouble shooting can bring esp...time consuming.I am now thinking of the ECM also Thanks and you may be saying ,"I told you ,so..."
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did about everything I can am ordering up a Engine Control Module I guess I have to get one with the same no. as mine to be sure it works -not just for a 94 civic.Right ? I think it will cost much money ?
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If you really think it is a ECM problem, and you verified powers and grounds
Looked at a 4 door, I saw 4 ECM versions. DX/LX is not available new. EX still looks available. Other differences for A/T and M/T. (Didn't look at 2 or 3 door cars.)
Rebuilding your original may be a possibility too, some are more successful than others. Many parts stores have this service available. Many parts stores can get cheapo reman computers too. Ask around.
Looked at a 4 door, I saw 4 ECM versions. DX/LX is not available new. EX still looks available. Other differences for A/T and M/T. (Didn't look at 2 or 3 door cars.)
Rebuilding your original may be a possibility too, some are more successful than others. Many parts stores have this service available. Many parts stores can get cheapo reman computers too. Ask around.
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News Flash >other than Big Tex Burning up at the State Fair of Texas today,I took out the ECM it had alot of dust funk all over the outside then I opened it up used contact cleaner on back of pc board all terminal connections and put it back together and Viola -The pump started immediately ---will see it it continues after a nights rest ,but that is a good sign for me ,not to mention the dinero....I will post after I know more. Have a great day
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EZONE It Did the same as before ...I bought another ECM ,now it has worked perfectly for 4 days ---well You told me so and I ain't hating I am pleased you came up with the correct solution.....Thank you very much
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another problem -the check engine light is coming on alot when I stop and turn the key off it resets and off I go again then some where down the road at 70 or so mph it comes back on I turn the key off and it resets itself and stays off awhile over and over .... I checked the plug with the 2 wires I jumped to see the code, ---but the check light did not give me a blink whatsoever ---After checking it several times I took the back up fuse out to reset the ecm....I do note that my heat gauge never gets to the 1/2 mark but the heater works fine ,thought it might not be getting hot enough for the o2 sensor to work ,but if I knew the answers I would smart instead I struggle...any help would be greately appreciated
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ECM was used- it fixed the fuel elec problem ...the ck engine light ongoing way before I swapped the ecm and continued ...I'm trying to fix all the problems.
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So the CEL had been a previous unresolved problem......You may just have to try to read codes before you shut it off.
Make sure the memory backup fuse is good (engine compartment fusebox #32). If this fuse is shot then the ECM will dump memory at every key off cycle.
The 3 wire connector near the 2 wire SCS (code check) connector is for a Honda PGM scan tool.
Make sure the memory backup fuse is good (engine compartment fusebox #32). If this fuse is shot then the ECM will dump memory at every key off cycle.
The 3 wire connector near the 2 wire SCS (code check) connector is for a Honda PGM scan tool.
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the fuse is good -I will check the codes with engine running....it may take a day or two as I will drive my Buick for the next day ...when I pulled the fuse it lost all my preset stations on the radio as my crappy Chilton's book said it would.
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Well I checked it again and this time it said I have a fuel pressure regulator problem,clogged return line or vacuum leak-Cheapest i can find one is $ 95 ...will get it soon install it and see what happens ....
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What code did you retrieve?
And what $95 part are you firing out of the cannon?
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"Code 43: A problem in the Heated Oxygen Sensor (HO2S) circuit or a problem in the Fuel Supply System."
One of the first questions in the trouble chart asks:
"Is the code 43 accompanied by the MIL and poor driveability?"
(I really hate the trouble tree charts Honda used back then, they only lead to trouble. They never directly say what the computer is looking at or what it is looking for, the charts just dive into testing such-and-such for a specific thing, that may or may not be present at the time. Trouble trees suck.)
A code is rarely ever defined as "throw parts at car".
(There actually are code definitions that say this now though, but the code 43 on your car does not say to do this.)
Troubleshooting is not "randomly throwing parts chosen from a list of possible causes".
A fuel pressure test would prove or disprove the need for blowing money on a pressure regulator.
The computer had to see a sensor that indicated the engine was running either too rich or too lean for whatever operating conditions it was in at the time.
MANY things can cause this to happen.
Fuel pressure is but one area to consider.
There are other areas to consider and test.
(A scanner that works with the car would be a huge help and save a lot of time in the diagnosis for me, but there is little hope of the average Joe getting their hands on one.)
It could be as simple as a falsely reporting O2 sensor, that's the only sensor the ECM uses to judge and maintain fuel control.
It could be as simple as one of the other sensors giving inaccurate readings, causing too much or too little fuel to be injected. An ECT skewed could do it, so could a skewed MAP, a sensor ground circuit, etc.
But one must be able to discern one from another, one must be able to test.
See where I'm going with this yet?
Think about this: A tankfull of E-85 would cause the same code 43 on your car..... but you have no idea your spouse filled the tank with E-85.
What pats would you throw at the car to fix it now?
How would a pro figure this out?
How many "pro's" WOULDN'T figure this out, even after throwing every last part on the shopping list at the car?
I actually see this sort of thing a lot whenever gas prices get really high.
One of the first questions in the trouble chart asks:
"Is the code 43 accompanied by the MIL and poor driveability?"
(I really hate the trouble tree charts Honda used back then, they only lead to trouble. They never directly say what the computer is looking at or what it is looking for, the charts just dive into testing such-and-such for a specific thing, that may or may not be present at the time. Trouble trees suck.)
A code is rarely ever defined as "throw parts at car".
(There actually are code definitions that say this now though, but the code 43 on your car does not say to do this.)
Troubleshooting is not "randomly throwing parts chosen from a list of possible causes".
A fuel pressure test would prove or disprove the need for blowing money on a pressure regulator.
The computer had to see a sensor that indicated the engine was running either too rich or too lean for whatever operating conditions it was in at the time.
MANY things can cause this to happen.
Fuel pressure is but one area to consider.
There are other areas to consider and test.
(A scanner that works with the car would be a huge help and save a lot of time in the diagnosis for me, but there is little hope of the average Joe getting their hands on one.)
It could be as simple as a falsely reporting O2 sensor, that's the only sensor the ECM uses to judge and maintain fuel control.
It could be as simple as one of the other sensors giving inaccurate readings, causing too much or too little fuel to be injected. An ECT skewed could do it, so could a skewed MAP, a sensor ground circuit, etc.
But one must be able to discern one from another, one must be able to test.
See where I'm going with this yet?
Think about this: A tankfull of E-85 would cause the same code 43 on your car..... but you have no idea your spouse filled the tank with E-85.
What pats would you throw at the car to fix it now?
How would a pro figure this out?
How many "pro's" WOULDN'T figure this out, even after throwing every last part on the shopping list at the car?
I actually see this sort of thing a lot whenever gas prices get really high.
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"Code 43: A problem in the Heated Oxygen Sensor (HO2S) circuit or a problem in the Fuel Supply System."
One of the first questions in the trouble chart asks:
"Is the code 43 accompanied by the MIL and poor driveability?"
(I really hate the trouble tree charts Honda used back then, they only lead to trouble. They never directly say what the computer is looking at or what it is looking for, the charts just dive into testing such-and-such for a specific thing, that may or may not be present at the time. Trouble trees suck.)
A code is rarely ever defined as "throw parts at car".
(There actually are code definitions that say this now though, but the code 43 on your car does not say to do this.)
Troubleshooting is not "randomly throwing parts chosen from a list of possible causes".
A fuel pressure test would prove or disprove the need for blowing money on a pressure regulator.
The computer had to see a sensor that indicated the engine was running either too rich or too lean for whatever operating conditions it was in at the time.
MANY things can cause this to happen.
Fuel pressure is but one area to consider.
There are other areas to consider and test.
(A scanner that works with the car would be a huge help and save a lot of time in the diagnosis for me, but there is little hope of the average Joe getting their hands on one.)
It could be as simple as a falsely reporting O2 sensor, that's the only sensor the ECM uses to judge and maintain fuel control.
It could be as simple as one of the other sensors giving inaccurate readings, causing too much or too little fuel to be injected. An ECT skewed could do it, so could a skewed MAP, a sensor ground circuit, etc.
But one must be able to discern one from another, one must be able to test.
See where I'm going with this yet?
Think about this: A tankfull of E-85 would cause the same code 43 on your car..... but you have no idea your spouse filled the tank with E-85.
What pats would you throw at the car to fix it now?
How would a pro figure this out?
How many "pro's" WOULDN'T figure this out, even after throwing every last part on the shopping list at the car?
I actually see this sort of thing a lot whenever gas prices get really high.
One of the first questions in the trouble chart asks:
"Is the code 43 accompanied by the MIL and poor driveability?"
(I really hate the trouble tree charts Honda used back then, they only lead to trouble. They never directly say what the computer is looking at or what it is looking for, the charts just dive into testing such-and-such for a specific thing, that may or may not be present at the time. Trouble trees suck.)
A code is rarely ever defined as "throw parts at car".
(There actually are code definitions that say this now though, but the code 43 on your car does not say to do this.)
Troubleshooting is not "randomly throwing parts chosen from a list of possible causes".
A fuel pressure test would prove or disprove the need for blowing money on a pressure regulator.
The computer had to see a sensor that indicated the engine was running either too rich or too lean for whatever operating conditions it was in at the time.
MANY things can cause this to happen.
Fuel pressure is but one area to consider.
There are other areas to consider and test.
(A scanner that works with the car would be a huge help and save a lot of time in the diagnosis for me, but there is little hope of the average Joe getting their hands on one.)
It could be as simple as a falsely reporting O2 sensor, that's the only sensor the ECM uses to judge and maintain fuel control.
It could be as simple as one of the other sensors giving inaccurate readings, causing too much or too little fuel to be injected. An ECT skewed could do it, so could a skewed MAP, a sensor ground circuit, etc.
But one must be able to discern one from another, one must be able to test.
See where I'm going with this yet?
Think about this: A tankfull of E-85 would cause the same code 43 on your car..... but you have no idea your spouse filled the tank with E-85.
What pats would you throw at the car to fix it now?
How would a pro figure this out?
How many "pro's" WOULDN'T figure this out, even after throwing every last part on the shopping list at the car?
I actually see this sort of thing a lot whenever gas prices get really high.
Thanks it is going to be difficult I can see....the check engine light comes on and the drive ability does not change...it is all good except the damn light --I noticed it can happen climbing a grade although at other times too.If it does come on and somewhere down the road I turn the key off and restart it- it resets -it doesn't take that long for it to come back on at any speed or any grade or flat ground....do you think changing octane will help I think all the pumps say may contain up to 10% ethanol ...I have the new fuel pump filter and relay and used ecm -the check light was there before the pump and ecm filter and fuel pump relay was changed...
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Rep Power: 518 Re: 94 civic fuel electrical problem?
Difficult to fix it the right on the first try, for most people that aren't into this sort of thing. Trouble is, a very large percentage of people in this business can't do it either. Few shops, dealer or independent, employ a full staff of top shelf talent. Few shops have the tooling to make this a quick process.
Here again, one must be sensitive enough to really notice subtle changes in performance.
50% of the appliance users freak out and start getting oversensitive to every little nuance when the CEL comes on, and the other half can't tell that a single damn thing is wrong unless the car comes to a grinding halt.
Changing octane will not help.
10% Ethanol is perfectly acceptable and will cause zero problems.
If you think this could be a problem with the pump or filter, then stick a fuel pressure gauge on it, tape it to the windshield, and drive. See what the pressure is when the light comes on. If it is still within specs, then none of that is your problem.
I can watch O2 sensor values on a scanner and determine in only a few minutes if I even need to bother checking the fuel pressure at all. I could even use a plain voltmeter: If the O2 value stays above about .800v during a full throttle, redline RPM run through first and maybe second gear, I know I don't have a fuel volume issue.
In fact, if I didn't have a scanner available to me, I might just start with voltmeter reading the O2 sensor, drive around and see what is happening when the light comes on. Of course, I already know how that sensor works and what I should be seeing at almost any given operating condition.
the check engine light comes on and the drive ability does not change...it is all good except the damn light --
50% of the appliance users freak out and start getting oversensitive to every little nuance when the CEL comes on, and the other half can't tell that a single damn thing is wrong unless the car comes to a grinding halt.
I noticed it can happen climbing a grade although at other times too.If it does come on and somewhere down the road I turn the key off and restart it- it resets -it doesn't take that long for it to come back on at any speed or any grade or flat ground....do you think changing octane will help I think all the pumps say may contain up to 10% ethanol ...I have the new fuel pump filter and relay and used ecm -the check light was there before the pump and ecm filter and fuel pump relay was changed...
10% Ethanol is perfectly acceptable and will cause zero problems.
If you think this could be a problem with the pump or filter, then stick a fuel pressure gauge on it, tape it to the windshield, and drive. See what the pressure is when the light comes on. If it is still within specs, then none of that is your problem.
I can watch O2 sensor values on a scanner and determine in only a few minutes if I even need to bother checking the fuel pressure at all. I could even use a plain voltmeter: If the O2 value stays above about .800v during a full throttle, redline RPM run through first and maybe second gear, I know I don't have a fuel volume issue.
In fact, if I didn't have a scanner available to me, I might just start with voltmeter reading the O2 sensor, drive around and see what is happening when the light comes on. Of course, I already know how that sensor works and what I should be seeing at almost any given operating condition.
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Difficult to fix it the right on the first try, for most people that aren't into this sort of thing. Trouble is, a very large percentage of people in this business can't do it either. Few shops, dealer or independent, employ a full staff of top shelf talent. Few shops have the tooling to make this a quick process.
Here again, one must be sensitive enough to really notice subtle changes in performance.
50% of the appliance users freak out and start getting oversensitive to every little nuance when the CEL comes on, and the other half can't tell that a single damn thing is wrong unless the car comes to a grinding halt.
Changing octane will not help.
10% Ethanol is perfectly acceptable and will cause zero problems.
If you think this could be a problem with the pump or filter, then stick a fuel pressure gauge on it, tape it to the windshield, and drive. See what the pressure is when the light comes on. If it is still within specs, then none of that is your problem.
I can watch O2 sensor values on a scanner and determine in only a few minutes if I even need to bother checking the fuel pressure at all. I could even use a plain voltmeter: If the O2 value stays above about .800v during a full throttle, redline RPM run through first and maybe second gear, I know I don't have a fuel volume issue.
In fact, if I didn't have a scanner available to me, I might just start with voltmeter reading the O2 sensor, drive around and see what is happening when the light comes on. Of course, I already know how that sensor works and what I should be seeing at almost any given operating condition.
Here again, one must be sensitive enough to really notice subtle changes in performance.
50% of the appliance users freak out and start getting oversensitive to every little nuance when the CEL comes on, and the other half can't tell that a single damn thing is wrong unless the car comes to a grinding halt.
Changing octane will not help.
10% Ethanol is perfectly acceptable and will cause zero problems.
If you think this could be a problem with the pump or filter, then stick a fuel pressure gauge on it, tape it to the windshield, and drive. See what the pressure is when the light comes on. If it is still within specs, then none of that is your problem.
I can watch O2 sensor values on a scanner and determine in only a few minutes if I even need to bother checking the fuel pressure at all. I could even use a plain voltmeter: If the O2 value stays above about .800v during a full throttle, redline RPM run through first and maybe second gear, I know I don't have a fuel volume issue.
In fact, if I didn't have a scanner available to me, I might just start with voltmeter reading the O2 sensor, drive around and see what is happening when the light comes on. Of course, I already know how that sensor works and what I should be seeing at almost any given operating condition.
yep it would seem that 99 and .9% of us are in trouble --I thru a fuel pressure reg. on it and it worked for a half hr and did the same thing CEL on- if I ch the O2 sensor while it is running down the road and the voltage doesn't drop below .8 v then where do I go then? If the )2 sensor is reading such subtle changes how can I change the parameters of the sensor -probably not possible. Changing parts in vain sucks
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From: Midwest. Aiming about mid-chest
Rep Power: 518 Re: 94 civic fuel electrical problem?
if I ch the O2 sensor while it is running down the road and the voltage doesn't drop below .8 v
If you don't have a good grasp of how it works when everything is "right", there isn't much hope of you knowing when it is wrong.
According to what you just typed, you already lost this one. You didn't catch my entire statement here, you missed the important items that change the outcome of the entire mess:
If the O2 value stays above about .800v during a full throttle, redline RPM run through first and maybe second gear,
At WOT/redline the engine demands the most fuel flow it will ever be able to use.
At WOT the computer is programed to go to full enrichment.
If the engine is going lean under that condition, I can see it in the O2 reading.
If the O2 voltage isn't at the high end of its range under that WOT/Redline condition, "we got a problem".
Therefore the O2 sensor must reflect that condition in its output voltage reading under that specific condition (If that doesn't happen, if it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper).
The O2 sensor is supposed to fluctuate rapidly between 0 and 1 volts at most other "closed loop" conditions except "decel fuel shutoff".
then where do I go then? If the )2 sensor is reading such subtle changes how can I change the parameters of the sensor -probably not possible.
I USE it as a diagnostic aid.
If it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper.
I thru a fuel pressure reg. on it and it worked for a half hr and did the same thing CEL on
If you had TESTED fuel pressure, you could have proved the regulator wasn't needed and saved that $97 to use toward fixing the problem.
Test, don't guess.
The Zone loans tools like that.
Next thing most will do is replace a perfectly good fuel pump with a **** quality discount part, and STILL not fix the original problem PLUS they just installed a new problem (the **** quality part installation actually becomes a NEW problem). An equivalent action can be called "Drawing your gun, pulling the trigger, and shooting yourself in the foot". This is a scenario that happens all too often and can drive a sane person nuts.
You can't believe a new part can be bad, so you replace even MORE parts.....again, with even more low quality parts.
Vicious circle ensues.
Don't be like the typical Zone shopper and try to justify firing the parts cannon by saying "it needed all those parts anyway" when the original problem still isn't fixed.
If the only way you can check things is to replace them, then how on Earth would you know if the new part is bad too?
NEW could stand for "Never Ever Worked".
And YES, it even happens with high-quality parts too.
I could sit at my kitchen table and GUESS, and tell you to (EXAMPLE) replace the O2 sensor....and it might be a correct guess. If I decided that was it and *I* replaced the part, I'd use a factory sensor and be confident.
BUT if you toss a **** quality sensor at it (DangerZone favorite is Bosch), you may NEVER fix it, and/or cause even MORE codes and problems.
Factory used DENSO or NTK sensors, anything else may be considered "wrong".
Wow.
I'm on a roll, and I haven't even had a cuppa Java yet.
Sorry about that.
Happy T-day to you too.
Thread Starter
You can't judge a man's cover ,by how many times he's been booked!
Joined: Oct 2012
Posts: 21
Likes: 0
Rep Power: 0 Re: 94 civic fuel electrical problem?
Well, first off, you need to know how it is supposed to work and why.
If you don't have a good grasp of how it works when everything is "right", there isn't much hope of you knowing when it is wrong.
According to what you just typed, you already lost this one. You didn't catch my entire statement here, you missed the important items that change the outcome of the entire mess: The O2 sensor tells *ME* what is (should be) going on with the fuel system.
At WOT/redline the engine demands the most fuel flow it will ever be able to use.
At WOT the computer is programed to go to full enrichment.
If the engine is going lean under that condition, I can see it in the O2 reading.
If the O2 voltage isn't at the high end of its range under that WOT/Redline condition, "we got a problem".
Therefore the O2 sensor must reflect that condition in its output voltage reading under that specific condition (If that doesn't happen, if it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper).
The O2 sensor is supposed to fluctuate rapidly between 0 and 1 volts at most other "closed loop" conditions except "decel fuel shutoff".
You can't alter it.
I USE it as a diagnostic aid.
If it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper.
So it didn't fix a damn thing at all.
If you had TESTED fuel pressure, you could have proved the regulator wasn't needed and saved that $97 to use toward fixing the problem.
Test, don't guess.
The Zone loans tools like that.
Next thing most will do is replace a perfectly good fuel pump with a **** quality discount part, and STILL not fix the original problem PLUS they just installed a new problem (the **** quality part installation actually becomes a NEW problem). An equivalent action can be called "Drawing your gun, pulling the trigger, and shooting yourself in the foot". This is a scenario that happens all too often and can drive a sane person nuts.
You can't believe a new part can be bad, so you replace even MORE parts.....again, with even more low quality parts.
Vicious circle ensues.
Don't be like the typical Zone shopper and try to justify firing the parts cannon by saying "it needed all those parts anyway" when the original problem still isn't fixed.
If the only way you can check things is to replace them, then how on Earth would you know if the new part is bad too?
NEW could stand for "Never Ever Worked".
And YES, it even happens with high-quality parts too.
I could sit at my kitchen table and GUESS, and tell you to (EXAMPLE) replace the O2 sensor....and it might be a correct guess. If I decided that was it and *I* replaced the part, I'd use a factory sensor and be confident.
BUT if you toss a **** quality sensor at it (DangerZone favorite is Bosch), you may NEVER fix it, and/or cause even MORE codes and problems.
Factory used DENSO or NTK sensors, anything else may be considered "wrong".
Wow.
I'm on a roll, and I haven't even had a cuppa Java yet.
Sorry about that.
Happy T-day to you too.
If you don't have a good grasp of how it works when everything is "right", there isn't much hope of you knowing when it is wrong.
According to what you just typed, you already lost this one. You didn't catch my entire statement here, you missed the important items that change the outcome of the entire mess: The O2 sensor tells *ME* what is (should be) going on with the fuel system.
At WOT/redline the engine demands the most fuel flow it will ever be able to use.
At WOT the computer is programed to go to full enrichment.
If the engine is going lean under that condition, I can see it in the O2 reading.
If the O2 voltage isn't at the high end of its range under that WOT/Redline condition, "we got a problem".
Therefore the O2 sensor must reflect that condition in its output voltage reading under that specific condition (If that doesn't happen, if it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper).
The O2 sensor is supposed to fluctuate rapidly between 0 and 1 volts at most other "closed loop" conditions except "decel fuel shutoff".
You can't alter it.
I USE it as a diagnostic aid.
If it doesn't do exactly what I expect to see, then there is a problem and I start checking deeper.
So it didn't fix a damn thing at all.
If you had TESTED fuel pressure, you could have proved the regulator wasn't needed and saved that $97 to use toward fixing the problem.
Test, don't guess.
The Zone loans tools like that.
Next thing most will do is replace a perfectly good fuel pump with a **** quality discount part, and STILL not fix the original problem PLUS they just installed a new problem (the **** quality part installation actually becomes a NEW problem). An equivalent action can be called "Drawing your gun, pulling the trigger, and shooting yourself in the foot". This is a scenario that happens all too often and can drive a sane person nuts.
You can't believe a new part can be bad, so you replace even MORE parts.....again, with even more low quality parts.
Vicious circle ensues.
Don't be like the typical Zone shopper and try to justify firing the parts cannon by saying "it needed all those parts anyway" when the original problem still isn't fixed.
If the only way you can check things is to replace them, then how on Earth would you know if the new part is bad too?
NEW could stand for "Never Ever Worked".
And YES, it even happens with high-quality parts too.
I could sit at my kitchen table and GUESS, and tell you to (EXAMPLE) replace the O2 sensor....and it might be a correct guess. If I decided that was it and *I* replaced the part, I'd use a factory sensor and be confident.
BUT if you toss a **** quality sensor at it (DangerZone favorite is Bosch), you may NEVER fix it, and/or cause even MORE codes and problems.
Factory used DENSO or NTK sensors, anything else may be considered "wrong".
Wow.
I'm on a roll, and I haven't even had a cuppa Java yet.
Sorry about that.
Happy T-day to you too.
Thread Starter
You can't judge a man's cover ,by how many times he's been booked!
Joined: Oct 2012
Posts: 21
Likes: 0
Rep Power: 0 Re: 94 civic fuel electrical problem?
I havent replied cause I checked the o2 sensor with a meter and while doing it, the cel would not come on -I took off the meter and It had been over 5000miles and the CEL has not come on again ...so I was waiting to see what was happening....Electrics....can't figure musta been a loose wire that should come back ....thank you for all your help...
