Lockjaw

Ok well I have replaced the plugs with NGK's and added a new 02 sensor. Still having issues.

Discovered something really interesting. If I sit at idle for a while, the AC will quit working, so I put a voltmeter on the battery at home.

With AC on, lights on, and stereo system running, I get 15.2 volts or so at idle with no AC, AC compressor kicks on, it drops to 12.6 or so. Then back up then back down as it cycles. For a while. After about 10 minutes, the voltage will drop to 12.3 or so, and when it kicks off, back to 12.7.

So I am curious if my drivability issue isn't related to low alternator output, since getting it about 3k RPMS seems to make everything fine?

Also, you can see my lights flickering going down the road at night, and especially see the dash lights flicker inside at night, under 3k where the drivability issues show up.

Thoughts?

bsmiley

Can you run it up to a local auto parts store and have your battery & charging system checked? This is done for free in my area and is a reliable and easy way to find out if your alternator is able to handle a load...
Check your ground connections, replace them or clean them up.

ezone

1) Use a scanner to read ECT data (hopefully the actual temperature, not voltage) when this happens. The PCM can shut off the AC when the coolant temp indicates overheating......and you MAY not see this on your temp gauge.

2) Do the fans still kick on when you turn on the AC --- even though the compressor doesn't run?

Could be several reasons the AC quits. I'd approach this as a new and separate problem...until proven otherwise?

What you are seeing could just be the ELD system in action. The PCM uses the ELD to regulate charging at a high or low rate, depending on electric power and fuel economy needs.

Um....I had to search your handle history to find that thread.
I doubt the alt charging is related to the bucking.

Lockjaw

Yes the fans run when the compressor kicks on, and when it gets to hot. As cool as its been here lately there shouldn't be much need for cooling. I just replaced the big main cooling fan a few months ago, so I know its working properly.

I will check it with the scanner and see.

I did a load test on the battery a few months ago, its an Optima yellow top, and it put out 750 CCA, and its only rated at 450. Optima's are stout.

I have also noticed in the morning the car doesn't turn over like the battery is fully charged.

I am wondering if the alternator going south would cause the fuel pump to slow down. You can see the lights flickering going down the road.

Lockjaw

I mention the battery being low because I drive through town to get here, at low speeds. In the morning, when I go to work, its mostly highway, so I am over 3k.

ezone

Fans still kicking on means the system is still TRYING to run the compressor (unless I misunderstood what you wrote). So now this is narrowed down pretty good.


Next step is to determine if the compressor clutch is still getting powered up but not engaging when it doesn't work. (excessive clutch clearance, or weak/open mag. coil circuit)

If the clutch is not powered up, look for clutch relay stuck off.




Voltage drop test power and ground sides, between battery and starter.

ezone

Um, well first make sure the battery is still good and fully charged....Check voltage while cranking and amp draw of the starter.

If those are normal or amp draw of the starter is low and cranking is slow, then volt drop test.

Lockjaw

Ok well here is what I find. The code reader I have doesn't tell me voltage when running. But my temp stays around 199 degrees while idling. It idles around 700 rpms according to the reader.

One thing I find curious is the map sensor reading. Since I have had turbo vehicles normally I would expect to see vacuum at idle around 20 inches and it get progressively less towards 0 as I open the throttle. I see the opposite here.

The bucking is still going on, with or without the AC on. I really suspect the alternator isn't putting out all its worth, and that is causing issues with the fuel delivery.

After the car sat over the weekend, it turned over very slow on monday, but I think I left the code reader connected.

I had the battery tested a while back, its rated at 450 CCA and put out 750, so I doubt its bad. Its only about a year old and its an optima yellow top.

Lockjaw

And my lights pulse.

Sometimes I really hate this car. Between the bucking and it's got something clunking when I let off the throttle I swear. I checked the front and back motor mount, they are fine.

ezone

Both sound fine..... Once up to operating temp it should stay around ~180* ish on the low end and up to wherever the fan kicks on on the high end of the range.
Without looking, fan might kick on at 195-205 ish?


Have you been able to see what is the coolant temp reading is when the AC cuts out?


Also, after the car has sat overnight and the engine is stone cold, and before starting the engine, check your scanner and compare ECT to IAT.. They should agree within just a couple degrees.


That may just be how your tool reads it. If you connected a vac gauge it's gonna read what you expect.

I have my scanner set to read MAP in voltage instead of other choices (kpa, Hg, H2O).
You said the lights pulse, is it rhythmic and short (just a couple seconds), or random?

Try to find info about the ELD and how the computer uses that to regulate charging, it turns the alternator up and down depending on the battery SOC and for fuel conservation. Yes you can notice (many people do) the lights change brightness when it adjusts charging if you are looking for it.

I've done that too LOL.

Lockjaw

The pulsing occurs when the AC compressor is not engaged. It is rythmic too.

When the compressor kicks on, then the lights stabilize.

Lockjaw

Is ECT The coolant temp? If so, they were 2 degrees different when I left for lunch.

ezone

ECT = Engine Coolant Temperature

2 degrees difference is well within reason.

Lockjaw

Ok more data. Took the honda to advance today to let them check the battery and run a load test. My optima which put out 750 CCA when they tested it last fall only put out 550 or so, and the machine said it needed charging. I drove 25 miles in the dark to get there.

Said I had low cranking amps and 11.25 volts cranking. My no load voltage was 14.94 my loaded was 12.76. Has a 30mv ripple while its running, which is what I suspect is the reason for the bucking.

Thoughts?? You can see my lights flickering even at highway speeds.

Dude said my loaded voltage should have been higher.

ezone

I asked before, you did not answer: How rapid is this flicker or pulse? Seconds apart? A minute? What?

.

Did they sell you a new alternator yet?

Those words mean nothing to me. Where's the solid amp numbers?


At what amperage load? What RPM? What's the alternator output rated at?

What kind of tester was used?


With a real VAT tester (carbon pile) you can crank enough amp load to dang near kill the engine from low voltage. I think ours at work can load something like 500+ amps if the connections are good.

The little electronic handheld tester gizmos do it way different, and I still don't trust them because I have found they are not always accurate IMO.

75% accuracy is just as good as 100%....right?

Lockjaw

The flicker is back and forth about 1 second intervals.

They used their tester that connects to the battery it didn't give me any amperage numbers. Could I get that done at a dealership?

They suggested I remove the alternator and bring it in for a bench test and see if it puts out what it should.

From what I can see, a Civic EX alternator is supposed to put out a max of 70 amps.

Lockjaw

I will say this, the flickering occurs at about the same interval as the bucking. It doesn't change with RPM increases either.

So it flickers the same at idle on up. About like this ==>>

ezone

I doubt it. Dealers are supposed to use only the approved newfangled testers.....see my earlier comment about accuracy.

IMO they are designed (dumbed down) so any clown without two working brain cells can use it and get decent results, but it's not perfect and they can't give the info wanted right now.

There's a time and place for old school, but it takes working brain cells to use it and interpret results.
We still have one, and I think I'm the only one that uses it here.

Why remove it?
Find someone with an old school VAT (or equivalent) tester (and knows what to do with it), test done on the car, no wrenches involved. 20-30 seconds.
Picked an 03, shows as 70A.

Hensinger2010

Electronic Load Detector or E.L.D. in the fuse box limits the amounts of volts and in turn amps the alternator will put out based on current load and engine state. sorry ezone didn't see you covered it.

ezone

Ok makes more sense now that I have some time to read it. Makes me think there may be a regulator problem. If you connect a voltmeter on the battery while it is pulsing, you should be able to see the range of high and low voltages as it pulsates. Then I might want to check voltages on the control side of the alt....

Is this a replacement alternator already? (did I ask this already?) Bolts tight?


Todays example: Van towed in with dead battery and died on the road. Mechanic found dome light was on and it ran the battery down. Charged battery and tested both battery and charging system using the newfangled tester. Got a printout (that printout is like GOLD!) saying everything is hunky-dory.
It MUST be great because the printout from that fancy expensive newfangled tester said so!

Customer picks up the van and drives away.


Van towed in for the second time just hours after it left. Description of the problem is pretty much the same as before, died while running in the parking lot of a local store, and it just clicks when you try to start it.

Now what?









Does anyone see a problem here?

It just screams that it has an intermittently failing alternator.....but that fancy newfangled tester can't find it, and the person that worked in it can only use that newfangled tester.


What now?

Lockjaw

I suspect the alternator myself. It is a replacement alternator, the original owner replaced the factory one in 2010.

I go out this morning, it's cold, with a 1 year old Optima and it turns over slowly. Once it fires up and idles for about 30 seconds, turn it off, crank it back up, it turns over at a normal cranking speed.

The thing that really points me to an alternator issue now is driving at highway speeds for 30 miles or so, then about 5 minutes of stop and go at night, and the tester says the battery is low. Really???

Here is what I see when I put a volt meter on it. Initially the voltage at idle, with lights on, AC on, etc is upper 14's to low 15's. When the compressor kicks on, it drops into the 12.7 range, then bounces back up as it cycles off. For a while. Eventually it will drop to 12.3 or so, and then when it cycles off, 12.6. If you rev the engine, then that seems to fix it, temporarily.

Lockjaw

I am curious about this because one video on youtube describes drivability issues also. And flickering lights.

ezone

Ok guys, give this PDF link a read: http://www.skidmore.edu/~pdwyer/e/files/service_news/troubleshooting/dim_lights_eld.pdf

ezone

How cold is it there?

Lockjaw

Mid 30's in the am. Be colder this am. like in 20's

Lockjaw

Well I swapped out the ELD and the lights still flicker. Will see if anything changes driveability wise.

Hensinger2010

you said optima... yellow or red? the yellow tops group 51's are known to be junk (if you want an explanation of why ill be more than happy to elaborate) not that its specifically a problem if your still getting it started just future reference but It doesn't sound like the eld is the problem if your still producing 14 to 15 volts out of the alternator when it seems to be active, not so sure the alternator is the culprit either, it seems intermittent so I'm not sure, it could be, have you gone through the grounds? it sounds heavily like a weak ground, power grounding out somewhere, or the alternator. Also did you say it was rpm dependent?

Lockjaw

Yellow optima. After driving around more, in colder weather, the car drives better without all the stumbling. Every once in a while I think I notice some, but not to the extent before replacing the ELD.

I do not notice the lights flickering at idle, although I do think they do flicker at speed. The flickering remains at a constant repetition, it doesn't speed up or slow down with engine speed.

I put a volt meter on the battery and at idle, I am seeing over 14 volts, with some fluctuation back and forth. It isn't dropping into the 12's and staying there when the AC compressor kicks on as it did before

Something feels loose in the motor mounting or front suspension. I mainly notice this when letting off the gas like in a coasting situation and then getting back on the gas. To me it sounds like something on the passenger side. I replaced the front motor mount last year, and checked the rear one, its fine. So that leaves the one on the front corner and the one on the side. I don't know if some of what I feel isn't made worse by this movement that clunks.

What grounds are there to check besides the main one that attaches to the water neck?

Lockjaw

The stumbling is rpm dependent. It occurs mainly in the 2k to 3k range. Above 3k I don't notice it at all.

ezone

Follow the battery neg cable.