I have a strange idle problem, please advise

[94_B4000]

Hi I had to reregister under a different name because I can't find my old password and the password reset function isn't working for me. I've been a member for a few years I think I used 94_Mazda_4x4 as my UN.

In any case I have been having a rough jumpy idle for the past two months. This is a 94 B4000 4.0. I thought I had figured it out and i replaced the DPFE sensor, but the problem came back. Then my idler pulley fell off recenetly, and I thought I had found the answer there but a new pulley did nothing. My ac compressor just failed, but seems to spin freely as long as AC isn't on. I unpluggedthe compressor to ensure it doesn't try to kick on. Anyway, I'm not sure what to try next. The truck seems to run fine when I'm driving, it just won't idle smoothly. Any ideas? I keep seeing the MAF sensor come up in my searches. I don' want to spend money on parts unless I can pinpoint the prolem.

 

[Big Jim M]

Idle problems could be the IAC, MAF, air temp sender or coolant temp sender..
I'd start by cleaning the maf and the iac.
Big JIm

 

[94_B4000]

Idle problems could be the IAC, MAF, air temp sender or coolant temp sender..
I'd start by cleaning the maf and the iac.
Big JIm

I took the IAC out the other day and cleaned it out with WD40. That didn't do anything. I'll try cleaning the MAF.

 

[daniel3507]

Have you changed your fuel filter?

 

[94_B4000]

Have you changed your fuel filter?

Yup, I did the filter and the pump last August. Maybe one of the plug wires is shorting or something? But the engine seems to run smooth once I get past initial acceleration. A miss like that usually keeps up with RPM I thought.

 

[Daniel_187]

I took the IAC out the other day and cleaned it out with WD40. That didn't do anything. I'll try cleaning the MAF.

I would use a MAF cleaner or TB cleaner, WD40 will collect a lot of crap on the IAC

 

[94_B4000]

I would use a MAF cleaner or TB cleaner, WD40 will collect a lot of crap on the IAC

Yeah I didn't have any at the time and I was stuck home with the kids. I did just go out and get some MAF and a Trox Security T20. WTF is THAT about anyways? Another damn tool I had to get. Wouldn't a regular T20 bolt have done just as well, or perhaps just an Allan?

Well, I cleaned the MAF and we'll see what happens. I'll pull out the IAC again and hit it with some MAF cleaner too.

 

[94_B4000]

So far so good

The truck was idling pretty good this morning.

 

[Daniel_187]

Glad to hear it, and The tamper proof bits are dumb I hear you on that

 

[94_B4000]

Yeah now I need to tackle my AC compressor problem. I don;t know if I should replace the clutch or the whole thing. I see aftermarket compressors for as cheap as $160 online.

Those stupid torx security bolts are just plain dumb. I was already pissed when I first bought my Fiero because I had to go out and buy a whole set of regular torx. What's next smiley faced bolts?

 

[94_B4000]

It's back. F*&%!!! WTH?

 

[xentris02]

check your pvc or replace it. i have the same problem and it slightly made it better also my radiator flush slightly made it better too let me know if you come up with something