PCM/Idle problem

[MWM]

Hey guys,

I just installed the new PCM/flash from DC over the weekend, and ever since then (granted only 3 days now), everytime I start it up when its cold, the idle jumps between 500 and 750 until it hits temp at 170 degrees. It usually does that for about 5-8 minutes. Sounds like its bogging down when it hits 500 rpm then jumps back up to 750 rpm and so on for the duration.

This doesn't sound normal, but the PCM kicks butt otherwise. This is the only anamoly. Any ideas? Maybe I spilled some radiator fluid on the plug ahead of the throttle body? I don't know. Thanks!

 

[FlyingLow]

The flashes are supposed to idle higher. I think around 750 or so. I think your fluxing idle is just because it's cold. Try tapping the throttle a little next time and see if that affects it. Either way I wouldn't worry.

Smoke

 

[Madduc]

Dallas..cold??! Ha!! I'm getting down to ZERO tonight.

 

[Bone]

Dallas..cold??! Ha!! I'm getting down to ZERO tonight.

Rankine or Kelvin? :dontknow:

 

[Tom]

When I first flashed an EEC I was a little paranoid and I thought my idle was hunting... I know that flashes are supposed to take a while and the computer is supposed to learn but hey, what do I know. I let it idle for 10 minutes like I am supposed to and then started driving it around gently to allow the learning curve, blah blah blah... After 20 minutes it still hunted for idle just a little bit when I was at a stop light... I was thinking well maybe mine just needs more time to learn. It was getting a little warm in my car so I shut of the "defrost" on my car... :idea: All of the sudden the idle hunting was gone...

I am not sure if our trucks do the same as my car, but do you have your A/C on via the defroster???

 

[kalani]

my truck does that stock...ocasionally it does it untill i disconnect and reconnect the battery...

 

[MWM]

This is suspicious, right after I hooked up the PCM I started hearing a squealing from the belts. I figured it was just covered with anti-freeze and would dry off. Today the squealing was ridiculously loud and sounded grumbly like a bearing was going out, so I may have moved over to the other thread in here talking about a bad harmonic balancer or something similar.

I'm going to take the DC PCM out tonight, switch it back and run it up to the dealer tomorrow to fix the squeal. Doing that I will obviously disconnect the battery so that may help. Also, the hunting could be more of a dragging/bogging down if one of the pulleys is binding/dragging. Once I get it back, I'll rehook the PCM and hope it takes care of itself.

Thanks guys!

 

[RedSrt007]

Good to see your on the right track! Keep us posted...