Infamous Idle Problem????

[Skibug]

Ok I purchased this 96 2dr Sport auto tranny with the 4.0 V6 about a month ago. And it has had a bumpy idle ever since. When the truck is in gear the bumpy idle is not really noticable. It also is not very noticable whent he A/C compressor is on. The only time that it seems to be noticable is when in park or neutral at idle. I have cleaned the IAC Valve to where you could drink out of it. I have cleaned the MAF sensor. I used seafoam in the engin and that seemed to give me a bit more power but did not solve the idle problem.

What else should I look at? Start with the cheap stuff first then list the big buck things to look at/replace.

Should I go ahead and replace the IAC valve just to rule that out? I have read that these things go bad constantly on our trucks.

Any suggestions would be appreciated.

 

[Joe Fast]

Some of those trucks had bad MAFS. It could be a bad sensor or harness issue. Don't realy know how to check it other than swap/out/in. Sorry.

Joe

 

[mabulok]

Plugs, wires, air filter, oh...and dump the Fram oil filter, if that's what your using, it was causing mine to idle poorly. Put on a Purolator Pureone and ilde problem got better, along with the engine noise on start-up, and is now cured with all the above done.

 

[96ExplorerXLT]

Some of those trucks had bad MAFS. It could be a bad sensor or harness issue. Don't realy know how to check it other than swap/out/in. Sorry.

Joe

i had this same problem, i replaced mine and it helped quite a bit.

Does it idle from around 500 then jump to about 1250 and then back down?

 

[bmxking5]

I think I read on here somewhere that old/bad fuel filters could cause poor idling.

 

[aldive]

Change the fuel filter, clean the MAF and IAC,

I would recommend a good treatment with Sea Foam.

Good luck.....

 

[Skibug]

Well it is just a sharp bumpy idle between about 500-900rpm's. I will try fuel filter. Like I said above, I have cleaned the IAC and the MAF and sea foamed the engin with no success.

 

[TPLYNCH]

Could be the compressor on your A/C going. If the clutch is going bad/the pully getting harder to turn, it will put more of a strain on the engine, dropping idle more than the IAC can easily compensate for.

 

[Skibug]

Don't think would be the compressor TPLYNCH. It has the rough idle when the compressor is not on. It seems when the engin has a load like the AC it smoothes out the idle problem. I bought a fuel filter and since I do not know how long the plugs have been in there since I bought it used I am going to change those as well to see if this fixes my problem.

 

[cjbarron5]

hey mabulok changing oil filter brands helped idle problem?????????????????????? any one else care to venture into this discussion im not calling you a liar but i find that very odd have you tryed a fram agian just to rule it out totaly? im really curious about this cause if this is true then i have learned something new today