Guys, I need your help. my VE has an up and down idle, it goes from 700 down to under 500 then back up again. When I move off from a stop, it vibrates, like carzy. Here is my checklist, i have:

changed the plugs
new O2 sensor
new engine control and ignition control relays
ran diagnotstic on ECU, no codes(everything is ok)
cleaned the throttle body, EGR valve
tightened the belts
all the injectors click
tested the ignition coils (ok)
one thing though, when I unplug the injector that is closest to the right headlamp( forget whta # that one is) sometime i get a drop in idle and sometimes I don't . what is the solution to this problem other than getting a Pathfinder and forget the VE.

 

Does it do it cold or hot more? I noticed that you did not mention your TPS. How about your plug wires? You can do a power balance test by unplugging each plug wire at a time to see which cylinder is or could be bad. And also check for vaccum leaks. Use wd -40 and I have even seen it done with propane. Also your drop in idle when you unplug it sometimes maybe due to and injector starting to go bad( seafoam or injector cleaner may help). Carbon deposits or burnt vavles. Rotor and cap.

 

it does it hot and cold. I put in a new TPS. when i do the balance test on that same cylinder I was talking about would sometimes drop in rpm and sometimes nothing. Is there a way to really test the injector to make sure it's bad or going bad?

 

is this a standard (manual) transmission?

If so... perhaps you need to give it a lil' more gas

Brian

 

its an automatic. 146000 miles.

 

nevermind then...

 

Vacuum leak?

See other current thread "Surging Idle".

 

I think i found the problem. I pulled the spark plug out and found it had a brownish color at both ends of the ceramic section and found oil on the threads. what does that mean?
could that have caused the cylinder not firing or producing a rough idle and stumble when moving off?