Idle at 1500rpm? cant seem to fix

[ECLIPSE95]

I had a problem with my car having idle stuttering and now when my car warms up it idles at 1.5rpm and it does it sometimes when it is cold..and my check engine light comes on and we pulled codes and a vaccum leak and we found it and fixed it and it still does it..so far I have changed the spark plugs and checked the wires..changed out the vac lines and now I am about to goto the EGR valve..I think its leaking would that cause the idle to act like that? I need some help here

 

[crankbender]

This is idle surge or a similar problem. You are getting too much air either way.

http://www.dsm.org/how-tos/tttt/tttt3.html

check taht out.

 

[laserblue]

Please describe what you mean [specifically] by "idle studdering". What does it do "sometimes when it is cold"?
A high idle doesn't make my CEL come on... but I own a '91, and it's different than yours!
Anyway... many things cause high idle [and that annoying ruRR-rUrr-RUrr idle surge, which is caused by the CPU sensing high rpms, and cutting fuel to attempt to bring it down]. Basically too much air getting in from ANYWHERE will make a fast idle, whether it's a vacuum leak [or any air leak], or a stuck valve thingy [such as the idle air control valve, or cold engine fast idle valve, or whatever].

I don't have answers for you..... but if you post back with more details, maybe some DSM-brainiac will know where to lead you.

{and I assume that you meant 1.5krpm, right?}

 

[ECLIPSE95]

Originally posted by laserblue
Please describe what you mean [specifically] by "idle studdering". What does it do "sometimes when it is cold"?
A high idle doesn't make my CEL come on... but I own a '91, and it's different than yours!
Anyway... many things cause high idle [and that annoying ruRR-rUrr-RUrr idle surge, which is caused by the CPU sensing high rpms, and cutting fuel to attempt to bring it down]. Basically too much air getting in from ANYWHERE will make a fast idle, whether it's a vacuum leak [or any air leak], or a stuck valve thingy [such as the idle air control valve, or cold engine fast idle valve, or whatever].

I don't have answers for you..... but if you post back with more details, maybe some DSM-brainiac will know where to lead you.

{and I assume that you meant 1.5krpm, right?}

ya..1.5k RPM and tonight I was watching it and it was stuttering from 1.2k and 1.4k(cold) and then it warmed up after driving around it started to idle at 1.5k then 1.7k..er I am so confused so I hooked up the OBDII to it again and pulled codes and my throttle is like at 12% and isn't it suppose to be at 10% at idle? I'm not sure and my exaust was stuttering really bad and kinda skipping like my engine was missing then I replaced the MAP sensor and it works now but the RPM is way high...I just had my car re-programmed because I had a recall on my car (95 manual transmission..it was the only recall for that year and only on M/T trannys) because there was a second hose that ran from my cat? and it went to my intake box..and I ran fine for a week and it started this shit so I dunno...and I just put on a new intake..but I doubt that is causing it so I dunno I really need some help here...

 

[ECLIPSE95]

anyone?

Still can fix this damn problem..so far

-Checked Ignition wire
-Changed Plugs and Gapped em
-New vaccum hose
-Flushed Radator

now the CEL light came on again and I have to pull codes again tomorrow...new fuel filter is going in tomorrow..anyways again tonight I reved the engine and the stupid Idle stuck at 3,000RPM..:angry: I still can seem to find out whats wrong..I need some serious help before I spend some serious cash at a shop

 

[crankbender]

Originally posted by crankbender
This is idle surge or a similar problem. You are getting too much air either way.

http://www.dsm.org/how-tos/tttt/tttt3.html

check taht out.

please read that.....

 

[ECLIPSE95]

ya already did...I start working on doing those steps and see what happends..thankz

 

[tlcoll1]

FYI,

I had a 1500 RPM idle the other day. Turned
out the air flow sensor (MAS) line was broken,
so if you have an AFC, you might want to check
the wiring.

Tom
The ECU+ guy

 

[Doug99RS]

You'll need to start eliminating possible sources of a vacuum leak. The first things that come to mind are speed control components or a brake booster.

I would remove and plug all vacuum fittings on the intake manifold. There's a vacuum tree with three fittings on it, a vacuum fitting on the manifold, a larger fitting for brake booster on the manifold, and a larger one for PCV system . Plug them all off and see what changes. If nothing changes then you've got an intake manifold gasket leaking, Injector O-ring leaking, or Throttle body gasket. If you buy a can of brake cleaner and start spraying it around the intake you can find it very quickly.

A 2gnt will set a code pointing to a vacuum leak. The computer looks at the Throttle position sensor and knows it's closed, it looks at the Idle air control motor commanded position and knows that it's being commanded to close, it looks at MAP sensor readings and know that pressure is too high and it also sees that engine RPM does not match target idle settings.

The ONLY thing OTHER than a vacuum leak that can cause this problem (that I'm aware of) is a bad idle air control motor. If the computer is commanding it shut and the motor is stuck then the idle will not go down. You will need to check for all the vacuum leak sources and then check the motor itself.

We need some test results posted in order to rule things out and suggest more ideas.
Doug

 

[4x4 tsi]

On my car, all I did was mess with the set screw on the throttle body. It brought the idle back down from 1.5 to around 1. Try doing that.

 

[Doug99RS]

I would not recomend adjusting the idle set screw at this point. Reason being that you do not know if the TPS sensor is at 10% open or 0% open. This means that you don't know if you actually have a vacuum leak or if it's just the set-screw. The BISS is not the cure all/end all to idle problems and should not be adjusted without first verifying that there is not a vacuum leak or bad Idle Air Control motor.

 

[asexton6969]

Clear your CEL (disconnect battery) if it comes back on then pull the codes again. My friend had that problem and it turned out he hadnt erased the old code so it wasnt giving off the new code.

 

[unlikely hero]

Originally posted by tlcoll1
FYI,

I had a 1500 RPM idle the other day. Turned
out the air flow sensor (MAS) line was broken,
so if you have an AFC, you might want to check
the wiring.

Tom
The ECU+ guy

I'm having this same problem and checking w/ my AFC I'm not getting a reading off the air flow. Where did you're break at? Anyplace I should start looking?
=Jason-

 

[tlcoll1]

Originally posted by unlikely hero
I'm having this same problem and checking w/ my AFC I'm not getting a reading off the air flow. Where did you're break at? Anyplace I should start looking?
=Jason-

Try checking where you soldered the AFC wire into the harness. That's the most likely place.

Tom