My 94 3v-ze is idling rough. I took it to the toyota dealer who recommended replacing the VAF sensor, ignition coil and igniter, ignition wiring, O2 sensor, and cleaning the throttle body and injector. This seemed a little like the carpet bomb approach to me, so I took my truck home and decided I needed to learn to fix it myself.

I used the FSM to check the VAF with an ohmmeter and the readings looked okay. I checked the ignition coil and the readings were a little off, so i just replaced the coil and igniter. It seems to be a little better, but still running rough.

SHould I try replacing the VAF anyway? I have read that the cold start injector can sometimes cause this too, but it seemed pretty involved to check it out according to the FSM. Is it pretty difficult? Any tips or other suggestions are greatly appreciated.

 

describe rough, Is it sputtering? Bogging out?

 

Basically when the truck is idling the engine is shaking (if you look under the hood). If I'm in the truck, idling at a stop, I can feel the truck shaking. The shaking is especially obvious if I put my hand on the gearshift. The RPMs never dip really low and sputter. Not sure what bogging out is.

 

Hey Newcomer5 - that sounds like it may be a vacuum leak. I've had similar problems with Honda's that I've worked on - but haven't dealt with them on these trucks. I've got an '88 with a 3.0 that's having a problem that sounds like yours...

Anyone care to take a swing?

 

Check your compression. If ya didnt know, 3.0's have a bad tendency to burn exhaust valves

 

Thanks for the suggestions. I'll check the compression. I've never done it before. I checked the FSM and saw how to do it. Any tips or suggestions or things I should look out for?

 

Your compression numbers should be 10%-15% of each other. Make sure the engine cranks equally for each cylinder and hope for the best