91YotaExcab

Ok I have a 91 3.0 That Idles at about 500 rpm when cold and when i drive it it sputters then "catches up" and goes fine. after about 10 min of driving it completly stops and runs perfect. I have replaced the tps, maf done a full tune up... plugs, wires,cap,rotor, oil change and coolant flush. there was no water in the oil. or oil in the coolant. there is a slight exaust leak before my o2 sensor but if that was causing it wouldent it run like crap all the time? O and i have no cel. Any help would be much appreciated.

crews462

have you thought about water in your fuel? i had/have similar problem in my 89 and I've come to a conclusion of poor fuel from the winter thaw. changed fuel filter and all the rest like you. could help. my tps tested within spec so did the vam. seemed mine was the fuel. also brand of oil.

just a 22re

idel air valve its in the tb it alows more air in when cold to warm up and then controls the idle not sure if it will cause a cel but id check that man

91YotaExcab

Ive ran seafoam from the tank a couple times so im shure its not the gas. and ive replaced the fuel filter as well. IS the any way you can give me more info on where to find the idler air valve?

91YotaExcab

O ya i pulled out a couple of plugs after about 500 miles of driving and the tips are white. What would that signal?

abecedarian

check for vacuum leaks

91YotaExcab

Wouldent that cause it to run messed up all the time?

abecedarian

not necessarily. if the O2 sensor can compensate for the lean mixture, it'll go away once the O2 warms up- after 5-10 minutes or so.

abecedarian

you said the spark plug tips are white. does that mean there is no residue on the plugs, or that what is there is kind of ash colored and flaky looking?

91YotaExcab

ash colored and i would say there wasent any residue on them really just white in color

abecedarian

white/ash colored is normal considering the fuel additives they're adding lately. that basically rules out running rich, which alludes towards running lean.
so now you've got to find out if the cold enrichment system is working- if you're lean when cold at idle, it will idle low.

91YotaExcab

How would i go about doing that. ive never had to deal with anything more than the basic's when repairing my yota. things like starter, altenator and such. i wouldnent evan know where to start with that

abecedarian

I don't have the specifics for your truck handy, but there is a sensor that triggers the cold start injector(s) when the water temp is below 100F. so either that switch is bad or the injector(s) isn't firing when it should.
hopefully someone with v6 experience will chime in.
otherwise you can look at the FSM available that should have info about your truck: http://personal.utulsa.edu/~nathan-b...fsm/index.html