mikesmr

I'm having trouble with my 1994 Honda Civic EX. It is idling and running rough. The vibrates when it is idling. I have replaced the spark plugs, wires, distributor cap, rotor, and fuel filter. None of this changed anything. Does anyone have any clues to what this might be? Please help! Mike

Jrfish007

iTrader: (3)

Reset the idle curve and see if that helps.

To do this, first drive the car so that it is warmed up.
Then reset the ECU by either take out the fuse to the ECU or disconnect the battery for a few minutes.
Then turn the car on, let it set for 10 minutes, make sure the radio, A/C and everything is off and don't touch the gas, just let it set and idle by it's self.
Now turn the car off, wait a second and turn the car back on and drive it to 37 MPH and stop and do this a couple of times, then turn the car back off and on agian, should do the trick.

Try this, let us know what happens

gearbox

iTrader: (95)

change plugs with new, do proper torque tightening
check vtec solenoid control and replace, possibly oil pressure sensor
clean throttle body
use fp60/lc20 oil and fuel system cleaners from lubecontrol.com
if still exists, have the injectors removed and sent for cleaning, flow testing
get new plug wires
check throttle body sensors (specifically tps and idle air control IAC)
air filter
check the header for carbon buildup and clean if possible or replace with new
replace primary 02 sensor
if possible, check a/f reading on a dyno to figure out if rich or lean

mikesmr

Thanks for the advice. I'll give it a try.

gearbox

iTrader: (95)

i would say clean the throttle body first using spray cleaner they sell. Just spray on a soft cloth and wipe all over to get the black stuff off. Then spray a little on the tb valve hinges. Then reset the ecu and do the idle learn. thats a cheap and quick start.

mikesmr

Pulled the fuse for the ECU and it seemed to help a little temporarily. I haven't tried cleaning the throttle body yet. It seems like when I put the pedal to the floor it does not have much power or acceleration in addition to vibrating when idling.

Jrfish007

iTrader: (3)

humm.... sounds like more than just an idle problem, go through all the stuff gearbox mentioned, he pretty much named everything I could think of.

streetglower

iTrader: (13)

My best advice if you have already done the normal tune up, is to hook up a scanner to it and read the values of all the sensors and see if any of the sensors show any values out of range or show anything unusual. this way you have a chance to see what the electrical system is doing and then you can go from there.

Another thing is pull all the spark plugs and tell us what they look like. this will tell you whats going on in the cylinders as well possibly point you in the direction you might need to look.

gearbox

iTrader: (95)

my moms 92 accord had severe shaking at idle when driving. I cleaned the TB out and now it runs perfect. I couldn't believe what a difference it made. Also tighten the throttle cable; I have a diy for that somewhere. Cause if its too loose, the gas pedal will be unresponsive, and your car will never reach full throttle even with the pedal floored.

mikesmr

Thanks for all the advice. I'm not an expert at all this stuff, but I assume the TB is the throttle body? Is that where the cable comes in and there is what looks like coiled spring? Should I clean it with WD-40?
It almost seems to me that one of the cylinders is not working. This happened a few times before, but was short lived. While I was driving I could feel it kick back in and everything was smooth. This time it won't go away. Would fuel injector cleaner possibly help?

gearbox

iTrader: (95)

Its the metal thing your intake attaches to (where the air comes in). Has sensors on it and you have to remove the intake to see where you need to clean. There is a lever that opens the valve so you can clean around and on it. It will be in closed position. Only use the special TB cleaner they sell in a can.

yes fuel injector cleaner helps, but I would only use fp60 from lubecontrol.com and there's a group buy for 20% off thats ending. today is the last day.

Jrfish007

iTrader: (3)

Forgot about the plugs, check those and tell us what they look like.

mikesmr

I have replaced the plugs, wires, distributor cap, rotor, fuel filter and no change. Air filter is clean. If there was a problem with an injector would the check engine light come on? I have no warning lights on.

gearbox

iTrader: (95)

injector problem wouldn't trigger the light. a lost cylinder probably should.

streetglower

iTrader: (13)

I am not sure how the older civics are, but on the newer vehicles, if the injector goes out or fails or loses power, the ecm will reconize that and shut spark off to that cylinder and vice versa if you lose spark, and throw a check engine light for a misfire in the cylinder.

Now if you feel you may be misfiring, check for proper spark at each cylinder. Disconnect the fuel supply, and turn on the engine untill it dies. then pull out a plug and wire and connect the plug to the wire and ground the plug on the engine and crank it. you should see a spark jump from the plug to the engine. Do this with each cylinder. if one cylinder doesnt spark, you are misfiring in that cylinder.

Now you can also check to see if each cylinder is getting fuel. now I am not sure if the older civics are TBI or SFI/MFI. If each injector has a harness connecter on it, one by one with the engine running, pull the connecter off the injecter and see if the engine performance changes. If after you pull on and the car starts idiling rough, then that injector is working. But if the engine runs the same after removing it, you probably have a problem in that cylinder.

Jrfish007

iTrader: (3)

New plugs are not we are looking for... Is there any wierd colors (puple, green, orange, ect) or heavy carbon build up.

Compression check would be nice too.

Jrfish007

iTrader: (3)

the EG civic's are all PFI, no TBI, in fact I cann't think any Honda that was TBI... not sure though. Anyway, with the OBDI civics, unless a fuel injector is completely dead like you said, it won't throw a code, it'll just limp around untill the injector dies. But the wierd burn and/or A/F ratio generally throws an O2 code. Injectors are generally like light bulbs from what I've seen though, they either work or they don't. They can get cloged a little, but the componets inside generally work untill fine, then fail, but that's just what I've seen.

gearbox

iTrader: (95)

yea compression test would tell you immediately if somethings wrong with the cylinders. Pretty easy to do with the equipment. Also do you know if the car is odbI/II?

streetglower

iTrader: (13)

should be OBD 1, OBD 2 started in the middle of 95 or 96. He said he had a 1994.

streetglower

iTrader: (13)

so did you figure out the problem?

mikesmr

I have been out of town and have not had a chance to fool with it. I will let you know how it goes. Thanks for all the input.

tinman

Re-check your distributor very carefully. There was a run of bad bearings. Look under the rotor cover for any sign of rusty dust.

mikesmr

Ok I've got an update for you guys and I need some help. I cleaned out the throttle body and it made no cahnge. I put in some fuel injector cleaner and it didn't seem to do anything. While the car was idling I removed the wiring harness form each injector. Every one caused the car to almost stall except one. When I removed the wiring harness on that one it made no change, which points me to that injector I guess. However, I have no check engine light. It did light up when I removed the wire harness, but went back off as soon as I reconnected it. I also pulled the plug in that cylinder and held it to the engine block to look for spark. When I did that I saw no spark, but the engine stalled I have not been able to start it since. I wonder if it is due to the injector cleaner. I only has about 1/4 tank when I put it in. Should I buy a new injector? I was also told it could be the fuel pump. Is that possible with the problems I'm having? Please help me!

tinman

You may have fried your ignition module with that little stunt. It can also be the coil, (now) as I have had to replace a few in my time. The coils can get weak and eventually fail, but the car will run poorly until the coil dies. Don't disconnect a plug with the engine running. The Ignition won't like it. Do you have the internal coil in the distributor or external?

streetglower

iTrader: (13)

You said the car stalled and you only had a 1/4 of a tank of fuel in there. Check and see if you even have enough fuel to start the car. Turn the key to the on position and tell me where the fuel gauge reads. Even if the light isnt on, you may not have enough fuel to start the car. If you have adequate fuel, check for spark in each cylinder. Like tinman said, you may have fuked something up. Always make sure the engine is off before you check for spark.

But Befire you figure out what the original problem was, try and now find out why it doesnt start. I am not sure if the injector in that one cylinder was the problem, if it made no change to the condition of the car when you pulled the connecter, to me it should have set a check engine light in the first place. But maybe the injecter still worked, but could have been severly clogged and hardly putting out any fuel to the point where it wouldnt trigger the check engine light, and it also wouldnt have made any difference if it was pulled.

mikesmr

OK. How do I check the inginiton module and coil? What is the correct way to check for spark? When I did it I had the plug pulled and was holding it to the block when I had my wife crank the engine. There is plenty of fuel in the tank.

streetglower

iTrader: (13)

SO when you first checked for spark, did you actually pull a plug with the engine running or with it not running? And did you disable the fuel and physically check the spark on each cylinder. From how I have learned to check for spark is to diasable the fuel and to pull each wire and plug out and connect the plug to the wire and ground the plug to the block and crank it to see if the plug is firing. But if the engine doesnt run anyway, justs cranks, then no need to really disable the fuel. But I have been reading alot lately that this method is highly not recommended because it can damage solid state components. SO maybe someone can confirm that for me. There are also spark testers like this one http://www.cvfsupplycompany.com/inigspartes.html that you can connect to the plug and coil and check for a presence of a spark. This is my method that I am now going to start using when checking for spark. I even purchased one from my school. They also have these http://shop.store.yahoo.com/brandspl...6-otc7230.html which is the same way I suggested doing but instead just ground the plug to the engine and crank.

Now I am no expert on checking distributor based ignition systems, those have always been a pain for me to work on, so someone with better experience will have to answer that.

Now what happens when you crank the engine, does it just crank and not start, or does it not crank at all?

mikesmr

When I first checked I had the plug pulled and then started the engine. Now it is cranking, but won't turn over. Could I have possibly blown a fuse or damaged the coil?

mikesmr

Ok guys, I gave up on this thing. I had it towed this morning to get repaired. I will let you all know what the problem was when I find out. Thanks for the help.

streetglower

iTrader: (13)

sorry we couldnt help. Its just one of those things where we would have to be there to see it. Let us know though.