2000 Rodeo stumbling

[rer_carr]

Need Help.
2000 Rodeo 3.2L

Staring from cold the idle revs high. The car then pulls itself. If you turn it off and restart, it will stumble trying to find idle and sometimes stall. If it finds idle in park, it will stumble and stall after switching gears(Park to Reverse or Drive). On warm start up problem doesn't occur.

Already tried:
New IMG, upper and lower. New MAF. New EGR. New TPS. Cleaned throttle body and EGR tube. Fuel Pressure is in specs. New FPR. No vacuum leaks. New plugs. New Neutral safety switch(was melted).

Used Scan tool to see the MAP, IAT and O2 sensors appear to be working.

Any advice is appreciated. Been to dealer and two mechanics.

[tom4bren]

Intake manifold gasket leak???

[rer_carr]

I thought that to, however I can not find a leak. I used a scan tool to monitor short term fuel trim while spraying carb. cleaner and propane. No change in the stft or idle.

[jasonm621]

When i had a high/jumpy idle i replaced a cracked intake manifold gasket (pain in the ***) and that only fixed my high idle. But it always would jump up and down so i then replaced the PCV, FPR, and the TPS. Even tried disconnecting the power steering pressure sensor wire with no luck. Believe it or not this is the sequence that have fixed my bucking idle issue for 6 months now.
Step 1: Start engine.
Step 2: Disconnect the TPS (you'll immediatly get a CEL and maybe a "CHECK TRANS" light)
Step 3: After a minute or two plug back in the TPS (while engine is running)
Step 4: Shut engine off...
Complete!
After that your check engine light should stay on for a couple days and automatically erase the DTC from your computer. DO NOT MANUALLY ERASE DTC WITH OBD SCANNER TOOL!
Hope that solves your idle issue!

[rer_carr]

I'll give it a try. When I have disconnected the TPS in the past, the car dies almost instantly. Idle is controlled by the throttle plate. I will let you know.

[rer_carr]

Thanks for the tip in post #4, but the car dies instantly when disconnecting the TPS. I didn't think I was going to get it restarted after. On the test ride it seemed worst. Still need help. I tried the power steering disconnect and cleaning of the ground points.

[tom4bren]

How about a clogged exhaust system?

[rer_carr]

Thanks for helping tom. This problem has me beat. I'll check for clogged exhaust. Just an additional note the CEL is flashing under acceleration today. No codes stored. What is the best way to check for clogged exhaust?

[tom4bren]

IDK.

I gotta check it on Boy's Samurai too.

Maybe this will give you some leads:

http://answers.yahoo.com/question/in...6234351AAvEUOs

A different article gave more info on reading the vacuum to determine if you have a clogged exhaust & how badly it's clogged.

Since the Samurai is an 88 & will never be tested for emissions, I've been thinking about just removing the cat & putting a piece of pipe in place of it.

[PK]

IIRC, a "flashing" CEL is a warning you are about to do damage, like low oil pressure or high temperature.
Better check it out real soon.

PK

[rer_carr]

vacuum testing does not show clogged exhaust. Still want to do a back pressure test. I gotta get the tool for that. The flashing stopped, but it did stall while driving down the road. Anyone know how to troubleshoot the ion sensing module?

[rer_carr]

update: problem has been nonexistent for two days and several trips. Only thing I've done is disconnect the power steering pressure switch and change power steering fluid. The car acted up once after the switch was disconnected so I don't think that is it. I did find out my cruise control does not work and fiddled with it.