'90 Camry w/ v6 stalls constantly

[synth]

Hello everyone,

I'm new to the forums here and was glad to find someone that has a similar issue(ky91camry's post http://www.toyotanation.com/forum/t169478.html). , I was beginning to think no one here had experienced this problem. Hopefully it's an easy fix. I'm trying to help out my dad with his '90 Camry w/ the V6 and this is what happens.

It will start up however it runs rough and it seems like the ECU is trying to keep the car from stalling. Sometimes it will almost stall while driving and the CEL will light up for 5 seconds. It will sometimes stall as soon as we have to stop the car. RPM's will bounce between 600 and 1100 while idling and sometimes will stabilize itself to 800 RPM's at idle for a while.

We have changed his air filter, replaced the vane assembly on top of the filter, cleaned out the throttle body using throttle body cleaner, changed spark plugs and spark plug wires. Distributor is fine as well. Checked vacuum hoses and all are fine.

We're lost right now as we don't know what it could be. Last thought was that it was either not getting enough air or a fuel injector is failing.

Any thoughts?

- Synth

[synth]

BTW, where is the EGR valve located on the V6?

[Doctor J]

On V-6 the EGR will rather plug up then leak.It is fairly big assembly with water cooling lines attached to the back of the intake plenum. You have mentioned the check engine light was on for 5 seconds.
Would you be able to pull the trouble code out to give us more clue. Personally, I am thinking about the throttle pos. sensor. If idle terminals will not close, the engine will miss and stall at deceleration, when fans are kicking in or when drive is selected. This condition will set code 51.

[mxsurf]

Could be the ignighter, mine wqas erratic and would die off shortly. Mike

[synth]

I will try to get the code. Is the TPS located in the throttle body?

[Doctor J]

Yes.

[marc780]

I dont know this applies to your year car, but one time i had to adjust the throttle postion sensor after a butterfly cleaning, i had knocked something out of alignment. and through trial and error, mostly error, i loosed the screws on this thing and just rotating the TPI fixed it.

Also i think your guess may be right, it could be one of the fuel injectors going out, clogged up or dead. an easy way to do a cursory check: remove the electrical connector from one injector at a time until no difference in idle is noted. In other words if you disconnect one particular injector, and the engine idle and revving is unchanged, this injector could be dead.