2,650 RPM Idle!!!

[Blown&Injected]

I think I may have some harness problems as the car is doing some strange stuff.

I had a problem with no start/backfire .http://www.turbobuick.com/forums/showthread.php?t=218132&referrerid=1527 Was told to re-set the Cam Sensor. Cam sensor was set right - did not move it except to watch the needle on the meter drop from about 7v to 0v. I stayed in the same place by eyeball - could have been +/- a few degrees but for what seems to be something that one may just get in the ball park, that should not have mattered.

So I essentially did nothing and rolled my eyes as I hit the key - But it fired right up!!!

And then died. Acted like the fuel pump primed but never turned back on - started in to high idle and instead of settling down is just died. So I put my foot on the throttle and feather it - just barely cracking the throttle and it keeps it running but at way high RPM's.

The thing will idle at 2,650 RPM's but will not settle down from there.

There are some potential issues:

I blocked off the EGR - do not know if the chip is set for no EGR, so I plugged in the EGR solenoid but eliminated the vacuum lines. There is just one line going from the check valve to the 3 way check valve on the firewall.

No screens in the MAF, but it is a less than 7K mile GM MAF that was working before...

The GN T-Type Org says the engine must be warm-closed loop- to set the IAC. IAC Reset Procedure Guess I will let it rev until warm but something just does not seem right - it has never done this before on new engine start up...

What could I be missing here?

 

[Ormand]

Check all the hoses, and make sure you don't have big vacuum leak somewhere, or air getting by the MAF. Do you have a scan tool? That would help.

 

[TurboDave]

The problem as you describe it sounds very much like a massive vacuum leak. Something like you'd see if a hose somewhere between the MAF and Throttle body were not clamped, or like the time I forgot to tighten the screws holding the vacuum block on top of the Throttle body....stuff like that.

 

[Blown&Injected]

Hi, and THANKS!

Some new info - looks like you guys are right as usual

It seems way to bad to be a vacuum leak but when I was near the engine and feathered the throttle by hand, I was close enough to hear and feel massive air from the EGR block off plate.

Had to be some serious air from somewhere as I backed the "idle" screw back and held the throttle blade tight - closed and it was still reving strong.

TPS is at .32 closed and 4.76 WOT
MAF shows 3 with just key-on/engine-off and about 24 when it is about 2,500 RPM's - super fast idle. It would normally be 7 to 9 at normal idle but do not know what it should read in neutral holding about 2500 revs.

 

[TurboDave]

Hi, and THANKS!

Some new info - looks like you guys are right as usual

It seems way to bad to be a vacuum leak but when I was near the engine and feathered the throttle by hand, I was close enough to hear and feel massive air from the EGR block off plate.

Had to be some serious air from somewhere as I backed the "idle" screw back and held the throttle blade tight - closed and it was still reving strong.

TPS is at .32 closed and 4.76 WOT
MAF shows 3 with just key-on/engine-off and about 24 when it is about 2,500 RPM's - super fast idle. It would normally be 7 to 9 at normal idle but do not know what it should read in neutral holding about 2500 revs.

That's NOT an idle screw you backed out, that's the IAC minimum air bleed adjustment. That's why your idle tps is so whacked out of adjustment now (It's WAY too low for idle value). DO NOT try to adjust idle rpm with that screw. There's a whole procedure on how to use that screw to set an optimum IAC value. Put the screw back about where it was (should be maybe one thread showing through on the screw where in comes through that little block it's mounted in) and make sure your TPS value is correct (.40-.44).
It's not always a good idea to start adjusting things on a computer controlled car if you're not sure/familiar what the adjustment is for or does.

 

[Blown&Injected]

I am very familiar with the adjustments on the car but not sure if there is a too low value there - there is a reason I made NO mention of an idle screw but an "idle" screw - just like I call the hub, even though I have a BHJ Harmonic Dampener, a "balancer" it just avoids some confusion.

Besides that screw is only used for idle "type" adjustments.

Thanks for the help.

It seems to be good now

 

[microELVIS]

Funny seeing you had a very high idle, I currently have a no idle. I have to give it gas to keep it running. The tps is correct, iac however i cannot set because the car doesnt stay running without gas. Its been a long time diagnosing this problem, with tlink readings and waiting to borrow a maf. The maf didnt change anything. I dont see any obvious vac leaks, this is just way weird and it just started happening on a whim. But anyways im getting directscan in, hopefully I can get some new numbers, faster ones anyways.

 

[martymcsuperfly]

I wish i had an idea to help! My car does the same thing as both of you! I also checked vaccum leaks, mass air, etc. Mine wont stay running without gas...goodness! We are in the exact same boat! mine also did the for NAR. (no apparent reason)

 

[microELVIS]

Yea so far its not the maf, and not the vacuum brake booster. The only thing I can think of now is try closing the pcv valve tube and see if it will idle. Im still getting 16psi vac on the guage though.

If you figure anything our marty let me know.

This is crazyyyyynessss

 

[TulsaGN]

I don't know if the several of you that are having the same problem ever got that fixed, but mine was doing the same things(not running unless I give it gas), and I bought a new IAC and reset everything and POOF, fixed. I scanned everything, called everybody, had posts, and finally said screw it, I'm just going to buy a new IAC. Damn glad I did. What a pain in the arse and wasting of hours. Good Luck.