Surging Idle, at startup.
04-04-2007, 10:16 AM
#1
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Join Date: Oct 2006
Location: Woodstock, GA
Posts: 2,594
Surging Idle, at startup.
O.k. here is what I have discovered, I had a post about my ac cutting the engine off. Well I started thinking about how my car acts when I first start it up, normal temp. or cold. The motor turns over great and for about 10 seconds it searches for idle, goes from 500 rpm to right at 900 rpm and stays at 900 rpm, runs great at this point. The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd, and I bought the car with a cai, I checked the iac out with another one I had laying around and it did the same. What are your thoughts on this? btw I am not worried about the ac, I can get around it for now, if I cure the idle issue, I think it will cure the ac issue. The only vacuum lines that are not connected are the ones going to the smog pump. sorry for the book.
04-04-2007, 10:47 AM
#2
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Join Date: Oct 2005
Location: Ohio USA
Posts: 4,616
RE: Surging Idle, at startup.
ORIGINAL: tmajikman
O.k. here is what I have discovered, I had a post about my ac cutting the engine off. Well I started thinking about how my car acts when I first start it up, normal temp. or cold. The motor turns over great and for about 10 seconds it searches for idle, goes from 500 rpm to right at 900 rpm and stays at 900 rpm, runs great at this point. The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd, and I bought the car with a cai, I checked the iac out with another one I had laying around and it did the same. What are your thoughts on this? btw I am not worried about the ac, I can get around it for now, if I cure the idle issue, I think it will cure the ac issue. The only vacuum lines that are not connected are the ones going to the smog pump. sorry for the book.
O.k. here is what I have discovered, I had a post about my ac cutting the engine off. Well I started thinking about how my car acts when I first start it up, normal temp. or cold. The motor turns over great and for about 10 seconds it searches for idle, goes from 500 rpm to right at 900 rpm and stays at 900 rpm, runs great at this point. The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd, and I bought the car with a cai, I checked the iac out with another one I had laying around and it did the same. What are your thoughts on this? btw I am not worried about the ac, I can get around it for now, if I cure the idle issue, I think it will cure the ac issue. The only vacuum lines that are not connected are the ones going to the smog pump. sorry for the book.
What happened to the lines from the smog pump to the rear of the cylinder heads? Are they plugged?
04-04-2007, 10:52 AM
#3
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Join Date: Oct 2006
Location: Woodstock, GA
Posts: 2,594
RE: Surging Idle, at startup.
ORIGINAL: aode06
I didnt know the smog pump had any vacum lines.
What happened to the lines from the smog pump to the rear of the cylinder heads? Are they plugged?
ORIGINAL: tmajikman
O.k. here is what I have discovered, I had a post about my ac cutting the engine off. Well I started thinking about how my car acts when I first start it up, normal temp. or cold. The motor turns over great and for about 10 seconds it searches for idle, goes from 500 rpm to right at 900 rpm and stays at 900 rpm, runs great at this point. The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd, and I bought the car with a cai, I checked the iac out with another one I had laying around and it did the same. What are your thoughts on this? btw I am not worried about the ac, I can get around it for now, if I cure the idle issue, I think it will cure the ac issue. The only vacuum lines that are not connected are the ones going to the smog pump. sorry for the book.
O.k. here is what I have discovered, I had a post about my ac cutting the engine off. Well I started thinking about how my car acts when I first start it up, normal temp. or cold. The motor turns over great and for about 10 seconds it searches for idle, goes from 500 rpm to right at 900 rpm and stays at 900 rpm, runs great at this point. The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd, and I bought the car with a cai, I checked the iac out with another one I had laying around and it did the same. What are your thoughts on this? btw I am not worried about the ac, I can get around it for now, if I cure the idle issue, I think it will cure the ac issue. The only vacuum lines that are not connected are the ones going to the smog pump. sorry for the book.
What happened to the lines from the smog pump to the rear of the cylinder heads? Are they plugged?
04-04-2007, 10:57 AM
#4
Join Date: Apr 2007
Posts: 35
RE: Surging Idle, at startup.
The ac does the same thing if I sit at idle if I turn the switch on then off. The car is sd. wat do u mean? THE CAR IS SD. ur on the right track from wat i readi dont understand that (SD)but try buying a bottle of brake cleaner and spraying it on the intake manifold or any vacuum lines to see if there is a rpm change to locate a vacuum leak
04-04-2007, 11:16 AM
#6
6th Gear Member
Join Date: Jun 2006
Location: Maine
Posts: 5,693
RE: Surging Idle, at startup.
Yes the smog pump / thermactor has vac lines that connect to it. And if you have open / disconnected lines, you probably have a vacuum leak. Spray some carb cleaner around the lines and around any other vacuum lines with the engine running and listen for any changes. That will give you a rough idea of where the leak is (if you have one.)
04-04-2007, 11:27 PM
#9
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Join Date: Oct 2006
Location: Woodstock, GA
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RE: Surging Idle, at startup.
I messed with the idle, and the surging only happens when I first start the car and when I turn off the ac. I need to look into the vacuum lines first, I know there are a few off. If the smog removed can I just plug those vacuums at the time.
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