I have a 1993 Camry Wagon with the 4cyl. motor. I bought it recently and it was running pretty decent, every so often while idling the RPMs would drop just briefly then it would smooth out just fine. I took it to my mechanic and we all agreed that it needed a full tune up. This included plugs, wires, fluids, and filters (air, cabin, and fuel). Once all that was done it was running great for about 10 minutes then it was inoperable. It would die constantly until the RPMs made it above 2000 (which was a chore and it would die mostly before you could get it that high). I took it to another mechanic who had more tools to diagnose what the issue was and he said 99% sure it was the Idle Control Valve, so $400 later the car was worse off than before and now is completely inoperable, it wont idle, nor when you give it gas it wont go at all.

Anyone have ANY ideas on what the issue might be, I cant throw any more money at this car and I cant sell it since it is un-drivable. My thoughts are it has to be an electrical issue or may need a new brain, but no one can seem to diagnose the problem. Any help is much appreciated!

 

You listed a lot of items, was anything else replaced such as distributor cap and rotor?

From your list the IAC valve was replaced, yes?

The computer seldom fails, this would be near the last of items suspected.

If you suspect an electrical issue the coil body can crack resulting in all kinds of idle and operational issues, pretty common.

Could be the replacement ign parts allowed the ign to operate better for a time. I would also inspect the dist cap and rotor for signs of excise erosion due to aching.

Operate the engine at night and look for arcing at the coil.

Other issues could be bad computer coolant temp sensor, bad O2 sensor.

 

Thank you for the reply toyomoho, it is much appreciated!

Yes, the cap and rotor were also replaced. The mechanic mentioned he checked the sensors (not quite sure how you do that) and said they were functioning fine. I will have them checked again (since this is another mechanic).

Yes, the IAC was replaced. I will have them look into these issues, the car is way beyond my mechanical skills at this point. I did read through a bunch of other threads and there were some similar issues, most of which mentioned a vacuum leak or coolant temperature sensor. Thanks so much for the help!

 

Alright, we replaced the IAC Valve, checked the cap and rotor as well as the wires (all are new and replaced twice just to make sure). Also a new O2 sensor and coolant temperature sensor and no such luck. The MAP sensor and the main brain are the last two we can figure, going out picking later this week to see if I can test those out. If not, then I may just push it off a cliff

 

Have you looked at the coil.