Our 92 Camry has a V6 and has caused no trouble for the first 158,000 miles. It has developed an intermittent problem that I am trying to solve. Occasionally when we pull up to a stop sign, it will idle roughly. On even rarer occasions, we can feel a "miss" at high speed. Revving the engine (or kicking it into passing gear to rev the engine) seems to fix the problem temporarily. We just spent $600 on a tune-up. Do any of you experts have a suggestion? My wife won't part with the car, so I need to fix it!

What exactly did they do for 600 dollars?

Your problems may be caused by (considering the age of the car): clogged fuel filter, bad distributor cap, etc...

Sam

They ran the diagnostic on their computer, then replaced the ignition parts and ran some sort of cleaner through the fuel system. Of course, $100 of the cost was for the labor to plug their computer into the interface in the car. I didn't suspect the fuel filter, because when it is the "OK" mode, you can rap it out to 6000 rpm with no problem. We also don't feel any "miss" when you accelerate from a stop sign even if it was idling roughly when stopped. I usually just drop it into neutral and rev the engine if it starts to idle roughly at a stop sign. I was wondering if there could be something in the system that measures air flow to control the mixture that could be sticking, and revving the engine breaks it loose.

They ran the diagnostic on their computer, then replaced the ignition parts and ran some sort of cleaner through the fuel system. Of course, $100 of the cost was for the labor to plug their computer into the interface in the car. I didn't suspect the fuel filter, because when it is the "OK" mode, you can rap it out to 6000 rpm with no problem. We also don't feel any "miss" when you accelerate from a stop sign even if it was idling roughly when stopped. I usually just drop it into neutral and rev the engine if it starts to idle roughly at a stop sign. I was wondering if there could be something in the system that measures air flow to control the mixture that could be sticking, and revving the engine breaks it loose.

Hello gdmoser,

Sure sounds like the ISC valve (idle speed control valve) or the IAC valve (idle air control valve)>>>>>> they are the same :) is gummed up and could be causing your rough idle. a good cleaning could solve your problems with the rough idle. :2cents: Good Luck.

Regards,
JOET/CAMRY

There are a few things you can check:

1. IAC valve as JOET/CAMRY has already suggested. The V6 IAC valves though are pretty robust so I doubt it, but it's possible.

2. EGR and EGR vacuum modulator. The valve may be sticking. Next time you come to a stop with a rough idle, get out and rap on the EGR valve with a spanner or something similar to see if you can get the engine to idle smoother.

3. TPS. It may be bad or out of adjustment.

4. Weak ignition due to wires, wrong plugs, bad distributor cap/rotor. If you had the plugs replaced in the tune up, make sure they were replaced with the NGK platinums. This car does not like Bosch plugs.

5. The 4" Air intake hose has cracks in it due to age (ie gets brittle). If this symptom of rough idling just started and was not present before the 'tuneup', this may be a cause because removal and re-installation of this (they cleaned the intake and TB, right?) can cause these cracks to open up and affect your air-fuel mixture. To inspect it, it is best to remove it and stretch it out by hand looking for any cracks in the folds.

6. Poor ground or alternator/battery problem. Check the voltage at the battery and the battery terminals.


dave mc

Thanks for the info,both of you. What puzzles me is that the "Check Engine" light has never come on, so I guess the problem is something the ECM doesn't monitor. I'll run the tests you suggested as soon as I can get the car away from my wife for a few hours. If I figure it out, I'll put a follow-up post in case if someone else has a similar problem.

The final chapter....

The problem quickly became worse, and revving the engine would no longer help, and it was clear that the engine was missfiring when under load. Checking back through my records, I could not find any mention of the fuel filter being replaced with a tune-up, even the last one. Shame on me... Aha, I thought, that must be the problem. I had the fuel filter replaced but the problem was still there. Since the intermittent problem had turned into a constant one, however, it was determined that one of the injectors was going bad. The injector was replaced, and we now have our old, reliable Camry back. :grinyes: The "check engine" light never came on through all the problems.

This is a great site. Keep up the good work!

Curious? What did it cost to replace the fuel filter? (I have never found the fuel filter to be the cause of any problem I had with my '90 Camry!). If I recall, it is not easy and not a $2.00 job to replace this filter.

Thanks for the responses so I'll know to look for a bad injector next time.

Sorry for the delay in responding...been busy. They charged me 3/4 hour labor and the cost of the filter. Here labor is $85.00 an hour and the filter was about $30. The filter on the 92 6cyl is located below the air filter, so the biggest part of the job is removing the air filter assembly to get to the filter.

HI gdmoser

I have 90 camry V6, 2.5L, auto. with same stalling problem at stop sign.

Would you mind to tell me how much does it cost to replace the injector (US or CDN dollars) ? How does the injector look like and can I buy a rebuilt one as OEM will surely cost me more than the car worth !

Thank you so much.