Idling problem - surging?
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Joined: May 2010
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Idling problem - surging?
Hey everyone
Ok I know there are probably tons of threads about idling issues. Here's my specific situation for my 1985:
When I bought the car last year, I noticed the idling jumped back and forth between say 500 - 800rpm when the car was warmed up. Very annoying and embarrassing. At the time, as a temporary "fix", I increased my idling speed with the screw adjustment so that the car would idle around 1000 or 1100 steadily and then I forgot about the issue.
The other day I changed my IAC and TPS because I needed a new TPS and I figured I'd change the IAC while I was at it. I removed the throttle body to change the IAC. Then of course, after I put it all back together, I was going to properly set the IAC and TPS according to Lars' article. (the IAC procedure involving disconnecting it, set the car at 400-450RPM, reconnect IAC, etc.).
My problem is that when I was trying to set my idling to 400-450rpm, i had that pesky old problem again with the idling surging between 400 and 800 rpm (then I remembered about having this problem last year!). Therefore I wasn't able to properly adjust my idling and had to set it back to approx. 1000rpm.
The hoses are connected tightly to the TB and the duct between the MAF and TB seems to be good too.
Any suggestions?
Ok I know there are probably tons of threads about idling issues. Here's my specific situation for my 1985:
When I bought the car last year, I noticed the idling jumped back and forth between say 500 - 800rpm when the car was warmed up. Very annoying and embarrassing. At the time, as a temporary "fix", I increased my idling speed with the screw adjustment so that the car would idle around 1000 or 1100 steadily and then I forgot about the issue.
The other day I changed my IAC and TPS because I needed a new TPS and I figured I'd change the IAC while I was at it. I removed the throttle body to change the IAC. Then of course, after I put it all back together, I was going to properly set the IAC and TPS according to Lars' article. (the IAC procedure involving disconnecting it, set the car at 400-450RPM, reconnect IAC, etc.).
My problem is that when I was trying to set my idling to 400-450rpm, i had that pesky old problem again with the idling surging between 400 and 800 rpm (then I remembered about having this problem last year!). Therefore I wasn't able to properly adjust my idling and had to set it back to approx. 1000rpm.
The hoses are connected tightly to the TB and the duct between the MAF and TB seems to be good too.
Any suggestions?
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Joined: Apr 2011
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Has it been driven since these adjustments and the IAC being d/c and reconnected?
It needs to run a few miles over 30 mph for a distance to re-learn and establish a pattern.
Idle when cold can be 800 then drop on its own down to 650 or less after it reaches its min temp..around 150 degrees. Setting the idle screw to 1000 rpm is not a good ldea...the ECM has no idea of what is going on..
Is TPS set right? No other vac leaks? egr leaks?
It needs to run a few miles over 30 mph for a distance to re-learn and establish a pattern.
Idle when cold can be 800 then drop on its own down to 650 or less after it reaches its min temp..around 150 degrees. Setting the idle screw to 1000 rpm is not a good ldea...the ECM has no idea of what is going on..
Is TPS set right? No other vac leaks? egr leaks?
