Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

1988 Regal Fiasco Many Sensor & Electrical Problems

Thread Tools
 
Search this Thread
 
Old Oct 27, 2013 | 03:52 PM
  #61  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

It must be too large to upload. Try these:


Reply
Old Oct 27, 2013 | 06:29 PM
  #62  
jwfirebird's Avatar
Senior Member
True Car Nut
 
Joined: Dec 2009
Posts: 9,616
Likes: 594
From: western,ny state
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

my inlaws car seems to be having a similar problem, and im not quite sure what it is at this point, i thought it was the iac but since you replaced your now im not so sure. i think in your case if you adjust the idle screw it maybe just bypassing the iac, havent done many obd1 vehicles but i dont think they even have one on the newer vehicles
Reply
Old Oct 27, 2013 | 06:39 PM
  #63  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

I'm torn between:

1) if I adjust the low idle screw, I'm ignoring the real problem - maybe transmission control related.

2) if I don't adjust it, I'm ignoring the correct procedure after working on the Throttle Body.

I think in my and your case, maybe drive it for awhile to see what'* up. It seems like both are intermittents and I don't have a SES light after fixing the vacuum snafu.
Reply
Old Oct 27, 2013 | 06:41 PM
  #64  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

Still thinking about it, you may very well be right about your in-laws IAC. Might be the best starting point if it acts up again.
Reply
Old Oct 27, 2013 | 06:53 PM
  #65  
jwfirebird's Avatar
Senior Member
True Car Nut
 
Joined: Dec 2009
Posts: 9,616
Likes: 594
From: western,ny state
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

then again it might just be a lowest setting then the iac adjusts up from there with load
Reply
Old Oct 27, 2013 | 07:52 PM
  #66  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

Yes, I agree. What I'm starting to think is, when the car is shut off, the IAC motor is set for the next re/starting position. If it is sticking when retracted due to age or dirt, when starting in closed loop again, I guess the only feedback for the ECM to readjust it is when the TPS sensor value changes like when we have to press the pedal or maybe O2 or other sensor gives adequate feedback. It'* a brainteaser for sure. Did the scanner show the right TPS voltage at closed throttle - I don't remember what you wrote.
Reply
Old Oct 27, 2013 | 08:24 PM
  #67  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

Originally Posted by B-1
Yes, I agree. What I'm starting to think is, when the car is shut off, the IAC motor is set for the next re/starting position. If it is sticking when retracted due to age or dirt, when starting in closed loop again, I guess the only feedback for the ECM to readjust it is when the TPS sensor value changes like when we have to press the pedal or maybe O2 or other sensor gives adequate feedback. It'* a brainteaser for sure. Did the scanner show the right TPS voltage at closed throttle - I don't remember what you wrote.
Oops, I meant: open loop on a cold restart. I see that your TPS was OK on the scanner.
Reply
Old Oct 28, 2013 | 06:24 AM
  #68  
jwfirebird's Avatar
Senior Member
True Car Nut
 
Joined: Dec 2009
Posts: 9,616
Likes: 594
From: western,ny state
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

on my Father inlaws buick the throttle position was 0 when off the throttle then any little movement on the petal would show an increase on the scanner
Reply
Old Oct 28, 2013 | 07:08 AM
  #69  
B-1's Avatar
B-1
Thread Starter
Member
Posts like a V-Tak
 
Joined: Sep 2013
Posts: 91
Likes: 0
From: Charleston, WV
B-1 is on a distinguished road
Default

Assuming on a deal like this, there are no spark/ignition related problems, then either (and since your sensors scan OK):

1) Too much/too little air through the IAC port at start-up - in relation to fuel delivery.
2) EGR valve going bad.
3) Too little fuel delivery at start-up via the ECM thinking it'* flooded.

The rough Idle at start up and needing to give it gas sounds like the vacuum problem I was struggling with, but mine did it at every start-up for the most part.
Reply
Old Oct 28, 2013 | 07:44 AM
  #70  
jwfirebird's Avatar
Senior Member
True Car Nut
 
Joined: Dec 2009
Posts: 9,616
Likes: 594
From: western,ny state
jwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond reputejwfirebird has a reputation beyond repute
Default

1)thats what i think is going on
2)on a 2000 the egr codes are oversensitive so if it was bad i would think it would set a code. there are no codes set either.
3) not sure how you would check that other than i checked maf, temp(air+coolant)sensor readings, fuel pressure, fuel trims, seems all normal
Reply



All times are GMT -4. The time now is 02:58 AM.