When cleaning my IAC valve, the Pintle and spring fell out

Tiny
COOLOLDS85
  • MEMBER
  • 1989 BUICK REGAL
  • 2.8L
  • 6 CYL
  • 2WD
  • 55,900 MILES
If I change my IAC does anyone know the correct GM IAC valve relearn procedure for my car listed above (V6 MFI)? So my Idle will be fine and will not rev higher than it should be.
Friday, April 20th, 2018 AT 9:19 PM

14 Replies

Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
Or since it is an older car I do not have to relearn it?
Was this
answer
helpful?
Yes
No
Saturday, April 21st, 2018 AT 12:23 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
Here is Prodemand's information on installing the new IAC, including how to get it set right.
Was this
answer
helpful?
Yes
No
Saturday, April 21st, 2018 AT 3:22 AM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
I know there is a relearn process for when replacing an IAC control valve, but I came across an older Buick Dealer Service Bulletin from 1988 regarding the 2.8L V6 Engine Base Idle RPM Adjustment for the Idle Air Control Valve relearn process.

Buick stated that all 2.8L MPFI V-6 Engine calibrations for 1988 and 1987 service include a feature which stores in ECM memory the Idle Air Control Valve (IAC) Position at which the engine idles. Each vehicle will have a unique value, depending on the throttle body base air rate setting, deposit build up, etc. The IAC position information is continuously updated, during vehicle start operation, and stored in the ECM "keep alive memory when the engine is turned off. If the ECM is without battery power for any reason, then the IAC position information for a stable engine idle is lost and is replaced with a default value.

Buick than said to correct IAC position information due to a disconnected battery power and improve engine idle, you must perform the relearn procedure for the Idle Air Control Valve to work properly with smooth idle.

I have never knew you could do this before. So my point is do you have to do this procedure every time when you disconnect the battery or get a new battery to improve engine idle? Also, can this service process by Buick be done with 2.8L V-6 engines for the 1989 Model year as well? Such as if Buick says you do not need to perform this process for the 1988's and 1987's can it be done with the 1989's as well since it has the same displacement engine or did they change it? All the throttle body's worked the same way for all interchangeable 1988-1991 models that had this type of throttle body used.

If I can save myself some time by not disconnecting the battery when putting the new IAC this would save a lot of time. But I want to make sure I do not damage my engine. They said a base idle rpm adjustment is not required and should not be performed on 1988 Vehicles. Like I said above can this be matched with 1989 vehicles as well?
Was this
answer
helpful?
Yes
No
Wednesday, April 25th, 2018 AT 4:21 PM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
No need to relearn every time you disconnect. You might have to give the engine a a little gas to keep it running for a couple of minutes, but after that, it should be good to go. The reason being that the IAC valve is already set to a good running point. So the computer just has to get some data together to know a little more about running the engine.
Was this
answer
helpful?
Yes
No
Wednesday, April 25th, 2018 AT 6:43 PM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
So there is not a need to do that process above you listed? Or for the first time since it is new sensor I need to for better idle?
Was this
answer
helpful?
Yes
No
Wednesday, April 25th, 2018 AT 7:11 PM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
What I am saying is that you need to do that process when you install a new IAC, but not every time that you disconnect the battery.
Was this
answer
helpful?
Yes
No
Wednesday, April 25th, 2018 AT 7:19 PM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
Oh okay, thank you. Got side tracked to as what Buick meant when they said you did not need to relearn anything without connecting battery.
Was this
answer
helpful?
Yes
No
Wednesday, April 25th, 2018 AT 7:22 PM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
New one came into today. Can you tell me how to extend the pintle out further in the new one to look like the older one?
Was this
answer
helpful?
Yes
No
Thursday, April 26th, 2018 AT 12:55 PM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
Pintle is not even in the housing because it is not extended out.
Was this
answer
helpful?
Yes
No
Thursday, April 26th, 2018 AT 12:55 PM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
I read somewhere a while back to use a nine volt battery with wires hooked up to the leads of the IAC. Just do that until it is extended, and do not force it.
Was this
answer
helpful?
Yes
No
Friday, April 27th, 2018 AT 3:34 AM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
I actually do not have an idea how to do that. I thought the ECM would extend the pintle and spring. The directions on the IAC relearn said do not extend it because it could damage the part.
Was this
answer
helpful?
Yes
No
Friday, April 27th, 2018 AT 7:28 AM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
Actually scratch that. Stick it in there and start it. It may take a few tries or it may fire up and stall several times. It should eventually get the valve where it needs to be though. I remember that that is how I had to do one on my old 1989 Buick Riviera years ago. God I miss that car. Anyways, pop it in and fire it up.
Was this
answer
helpful?
Yes
No
Friday, April 27th, 2018 AT 6:49 PM
Tiny
COOLOLDS85
  • MEMBER
  • 173 POSTS
After that it will not stall months later would it? The idle will be adjusted after it is driven right?
Was this
answer
helpful?
Yes
No
Friday, April 27th, 2018 AT 7:32 PM
Tiny
HARRY P
  • MECHANIC
  • 2,292 POSTS
Yeah, I let mine just idle until it was right. Never had an issue after that and I had kept the car a few years afterwards.
Was this
answer
helpful?
Yes
No
Friday, April 27th, 2018 AT 7:36 PM

Please login or register to post a reply.

Sponsored links