High Idle problems

THAWA · Post by **THAWA** » Sun Jun 19, 2005 8:03 pm

Okay, I've got the new engine in, it's pretty much good, but it's idling pretty high, like 2,000 rpms or so. I fiddled with the original throttle body's stop screws and that made no difference. I replaced that with a throttle body whose screws were still factory. Still, no difference. I replaced the coolant temperature sensor as the first one was broken, no difference. I plugged the IAC valve lines, the car start, then die immediately. I unplugged the iac valve, the car runs and idles at around 1,500 rpms up to about 2,000 rpms at times. What could be the problem? Intake leak somewhere? I've reset the ECU so many times that I don't know what to do.

J-MoNeY · Post by **J-MoNeY** » Sun Jun 19, 2005 11:30 pm

Did you check the nuts for the cruse control and the throttle cable where they connect to the TB? When I put my newer engine in they were to tight causing the engine to idle high.

entirelyturbo · Post by **entirelyturbo** » Mon Jun 20, 2005 12:06 am

Like I said, I think it's IAC related. I think it's stuck open all the way.

Post by **Legacy777** » Mon Jun 20, 2005 12:56 am

Does your TB have an air bypass screw on the top of it, like this?

http://www.main.experiencetherave.com:8 ... images/tb/

THAWA · Post by **THAWA** » Mon Jun 20, 2005 2:20 am

The old one did, it was one of the screws I adjusted. The old one had the throttle completely closed. The new one I haven't touched, it was idling fine on the old engine. I'm going to go try cleaning and adjusting the iac valve, if that fixes it I'll swap to a known good and calibrated iac valve.

JasonGrahn · Post by **JasonGrahn** » Mon Jun 20, 2005 2:41 am

It's gotta be IAC related. When i put the 2.5 in my car, i had to get an adapter plate made to put my original IAC on the car, nothing else would work correctly.

THAWA · Post by **THAWA** » Mon Jun 20, 2005 3:22 am

when you remove the electronic protion of the IAC valve held on by two screws, should you be able to move the shaft inside with your hand?

dzx · Post by **dzx** » Mon Jun 20, 2005 5:26 am

What you described is the same exact thing my engine is doing. I switched the electronic part of the IAC today and it did nothing.

THAWA · Post by **THAWA** » Mon Jun 20, 2005 6:20 am

I can believe that if the mechanical part is stuck open.

J-MoNeY · Post by **J-MoNeY** » Mon Jun 20, 2005 6:33 am

J-MoNeY wrote:Did you check the nuts for the cruse control and the throttle cable where they connect to the TB? When I put my newer engine in they were to tight causing the engine to idle high.

TTT.

THAWA · Post by **THAWA** » Mon Jun 20, 2005 6:48 am

oh sorry, the throttle was never the problem, I had the throttle completely shut and it was still idling like this.

Post by **Legacy777** » Mon Jun 20, 2005 3:43 pm

THAWA wrote:when you remove the electronic protion of the IAC valve held on by two screws, should you be able to move the shaft inside with your hand?

Yes, you should be able to rotate the valve back and forth with your hand. Have someone start the car, and you turn the valve with your hand. Or just turn it all the way in one direction, then try to start the car. One way, idle will be really high, other way, car may not start or idle will be really low.

Just out of curiosity. Have you checked the IAC valve's duty % via Vikash's scan tool?

THAWA · Post by **THAWA** » Mon Jun 20, 2005 6:34 pm

Nope, but it doesn't matter. The mechanical part is frozen open.

Guess I know what I'm doing today. I did however test the valve using the FSM's instructions. The electrical part tested fine.

entirelyturbo · Post by **entirelyturbo** » Mon Jun 20, 2005 6:39 pm

Told ya

THAWA · Post by **THAWA** » Mon Jun 20, 2005 6:43 pm

Yeah yeah

I just didn't want to replace something I didn't have to.

JasonGrahn · Post by **JasonGrahn** » Mon Jun 20, 2005 7:01 pm

IN SUMMARY:

throttle closed, revving high, check ability of IAC.

THAWA · Post by **THAWA** » Mon Jun 20, 2005 7:12 pm

Well you should check both the mechaical part, and the electrical part.

JasonGrahn · Post by **JasonGrahn** » Mon Jun 20, 2005 7:51 pm

agreed and edited.

Matt Monson · Post by **Matt Monson** » Mon Jun 20, 2005 10:18 pm

There seems to be a run of IAC failures, I sold all four of the spares I had in my inventory in the last 30 days!!!

BAC5.2 · Post by **BAC5.2** » Tue Jun 21, 2005 12:55 am

I still have a BRAND NEW IAC valve...

THAWA · Post by **THAWA** » Tue Jun 21, 2005 3:47 am

I'm still not paying $200 bucks for one

.

Swapped valves, works fine now. The old one is like really bad. I took a screw driver and tried to pry it by the door, and it chipped part of it off!

entirelyturbo · Post by **entirelyturbo** » Tue Jun 21, 2005 4:24 am

THAWA wrote:I'm still not paying $200 bucks for one .

You wish... I paid $362 list new for mine

dzx · Post by **dzx** » Wed Jun 22, 2005 2:56 am

Poor phil, stuck with money you cant spend. Kinda like my 400 dollar subwoofer that holds my keys in my room.

dzx · Post by **dzx** » Fri Jun 24, 2005 2:12 am

I replaced the IAC and it seems to have solved most of the problem. Most of the time it idles normal now but sometimes it still idle's high.

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High Idle problems

High Idle problems