05-01-2008 | #1 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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High idle after running.. Some questions
I did some searching on here, but I need to be verified..
with key on, not running, secondary pump runs every 30 secs for about 10 secs maybe.. When I start the car the it idles around 700 rpm.. if I drive it a short bit it will not drop below 100 it seems. Can the secondary vacuum lines be a cause of the higher idle? Primary map is connected fine, as is fuel regulator. I took the vacuum hose off the driver side of plenum and blew air in it.. that is okay.. I know there are probably more I need to look at any spots more then others? I need to put my scanner on it and check the IAC steps and such too, but I did not have time tonight. just trying to see what I need to look at, I really don't want to pull the plenum but if I have to I will.
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
05-02-2008 | #2 |
Join Date: Oct 2004
Location: Folsom CA
Posts: 1,650
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Re: High idle after running.. Some questions
Jeff:
Had a similar problem on my '90, turned out to be a vacuum leak. On mine it was the funky PVC two hose connector just behind and under the throttle body on the drivers side. If it's not *EXACTLY* in the right position it leaks. I had a heck of a time getting mine to seal, I swore that if it ever gave me problems again I'd replace the f*ing thing with fuel hose and hose clamps. Have you tried tapping the throttle after the car comes to a stop? If that kicks the idle down then I'd say it's more likely in the throttle body. If the primary throttle body blade doesn't close all the way it'll cause idle problems. The mechanism might be gummed up a little and need a little WD40. Good luck! TomC
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TomC '90ZR1 #792 Honorary Pirate [B]If it ain't FUN, you're doing something terribly WRONG. [/B] |
05-02-2008 | #3 | |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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Re: High idle after running.. Some questions
Quote:
I also will reset the IAC and see if that helps.
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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05-02-2008 | #4 |
Join Date: Mar 2006
Location: Innsbrook, Missouri
Posts: 1,727
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Re: High idle after running.. Some questions
Hey, Jeff,
i get the same damn feeling, i just don't run anymore. I'm walking at every chance. Am I in the right post? where the hell am i ? |
05-02-2008 | #5 | |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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Re: High idle after running.. Some questions
Quote:
where are you? you are HERE!!! LOL
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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05-02-2008 | #6 |
Join Date: May 2007
Location: Chicagoland, IL
Posts: 9,698
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Re: High idle after running.. Some questions
Jeff,
You'll want to look at the IAC counts. I adjusted the MinAir on mine to the point where the throttle stop barely touches the throttle body. My idle is around 800rpm. I have been getting a slight surging which had me suspecting a vacuum leak but I think I have been able to smooth it out modifying the timing and VE at idle. Did you check line from secondary pump to under the plenum? Does it hold vacuum? See what MAP is at idle. Lgaff started his up and then did the IAC adjust and he says his idles fine now. This is where having the Ostrich really helps. I sat in the garage yesterday and played with the cal with motor running. I made successive changes to the Prop Gains and downloaded bin. Worked great. I could immediately see which direction I needed to make changes in without running back and forth to the eraser/burner. |
05-02-2008 | #7 | |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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Re: High idle after running.. Some questions
Quote:
http://zr1netregistry.com/forum/show...57&postcount=6 and This: http://zr1netregistry.com/forum/show...5&postcount=10 that were found in this thread: http://zr1netregistry.com/forum/show...ight=high+idle leads me to understand that it is not an issues with the secondary system My Secondary pump runs for a few seconds, then shuts off for a few then repeats.. As I said, I need to see what the scanner shows, but i will try the IAC reset first.. Start simple. I question it being a vacuum leak because when I start it the idle is fine, after the motor is running and I drive it a short bit the idle is high. If there is a vacuum leak it will be there when I start the car too, so I would never see the lower idle. I am unable to do too much right now though, my radiator is leaking too, found that yesterday. Pass Tank is Bulging athough there are no stress cracks yet leaking on front and back.. Good thing I have a spare
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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05-02-2008 | #8 |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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Re: High idle after running.. Some questions
Okay.. Tried IAC trick.. no change
all Hoses seem good as far as I can tell. BUT.... the PCV Vales were very loose, theat 2 to 1 rubber piece was loose on all 3 holes.. I uses a hose clmap for it on the tube to the front of the Plenum. for the 2 PCV valves I used a zip tie to keep them together wrpped top and bottom.. will that work.. don't know started it again and it did drop to abot 1000 on the tach (need to connect the scan tool though) the vacuum line from the bottom of the air horn goes to where? all other vacuum lines I blew into and all seem good
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
05-02-2008 | #9 |
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Re: High idle after running.. Some questions
Jeff, for giggles, go get a vinyl 3 ring binder and slap the flat surface over the air horn inlet. See if it dies.
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05-02-2008 | #10 | |
Join Date: Jul 2007
Location: Bartlett, IL
Posts: 7,155
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Re: High idle after running.. Some questions
Quote:
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1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978 |
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