Engine idle hunting, why and causes

[ronbuick]

Just got the motor back in after almost a year after having popped the ol HG,
and now the idle is all over the place, now in my smartness I installed my cracked drivers side manifold instead of the other uncracked one, hey its been almost a year, and I also removed my 83lb injectors and installed my 009's , now my modded ECM should work for both injectors, correct?? and also had the heads redone at the same time, so why is my rpm's at idle up to about 15-1800rpm then drop down to almost dying then repeat the process all over, under throttle she seems to run out well, so looking for some help
here and some ideas, thanks.

Ron

 

[DailyDrifter]

Possibly IAC needs to be reset. Or vacuum leak of some type

 

[ronbuick]

Throttle respose from idle in park has a big lag before the R's climb, also
went out and tried to build a little boost from a dead stop and it would not even do that, just not right, so ideas keep em comming, thanks.

Ron

 

[bmackinnon]

The cracked header CERTAINLY doesn't help.... you DID change the chip for the 009's, right? Vacuum leak is the most likely culprit.... double/triple check I/C hoses, maf pipe connections..... what are the o2's? tps? iac numbers? Start spraying carb cleaner or propane around the intake, injector bosses, plenum, vac block, etc.... most likely a vac. leak....

 

[ronbuick]

Yes a TT chip for 009's. I will keep looking for that vac leak, but just not sure
that is the problem, also forgot to mention that my wastegate solenoid is
missing and so it is not plugged in, just can not find it at the moment, so more plausible ideas please, thanks

Ron

 

[DailyDrifter]

Yes a TT chip for 009's. I will keep looking for that vac leak, but just not sure
that is the problem, also forgot to mention that my wastegate solenoid is
missing and so it is not plugged in, just can not find it at the moment, so more plausible ideas please, thanks

Ron

Does your car need the wastegate solenoid? Or do you have a manual boost controller?

 

[ronbuick]

right now it needs it, the hoses hook to nothing right now, I'm not sure if it is even needed, but maybe it is causing my problem, but I'm not sure it is causing the problem, but again maybe it is, I need more info, so that also means that the red wastegate connector is connecting to nothing, thanks.

Ron

 

[87geeinn]

Ron,

I'm willing to bet your cracked header is the likely culprit. Try checking out this post of mine. I've been tracking a cruddy idle for quite some time. Pay particular attention to the last few posts on the second page of the thread. Maybe it will help:

Help with lean idle - TurboTweak Forum

 

[ronbuick]

I will change the header this week end maybe, lol, also I was thinking that the E-90 I have in the gas tank for the past year could have picked up some moisture thru condensation even though my shop is kept at 50 deg. during the winter months, I'm starting to think that that could also be the problem, what say you guys! thanks.

Ron

 

[DailyDrifter]

You might want to connect the wastegate solenoid back up. Sounds like a vac leak. I would hook everything back up and see where that gets you. Or spray carb cleaner around that area.