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06-27-2012 | #1 |
Join Date: Feb 2010
Location: Pendleton, IN
Posts: 3,904
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IAC Maintenance
Solved an issue today.
Started the car this morning and after about 15-30 seconds the idle began to rise to over 3k. I blipped the throttle and it did nt not come back down. Background Info * My car had ran very inconsistantly shortly before Bowling Green in May and after I got home a fuel pump failed. * June 1st - Installed CHEAP Airtx fuel pumps (I had them, so I used them) Still installed them but plan on installing Bosch pumps next week. I just don't have a lot of trust in the Airtex pumps, personally. * For the past week, when I would first drive the car in the morning, I'd get a stumble from 1st to 2nd gear when pulling out of the neighboorhood. (Yesterday, it almost died due to starving or fuel.) After that, it runs OK but feels like it's starving for fuel, to an extent. You know how you can feel things to be different when you drive your car everyday. I felt that one of the cheap pumps was beginning to fail???? Today After my high idle occured, I checked the MAP hose and also the IAC connections. TPS was not loose. Shut off car and re-started. Idle was ok. Drove car and it still felt like it had a weak fuel condition from the pumps. I took the IAC loose and began to clean it with solvent.Wahla! A large chunk of carbon fell out onto my hand. The chunk was about 1/4" or larger and it was also thick. I finished cleaning the IAC and the spring and also the hole in the plenum. Re-attached the IAC and started the car. Seemed to idle just fine. (Be careful not to drop a screw underneath the plenum.) Telescoping magnets are a geat invention. LOL Drove the car. Exhaust note was nice and smooth and no more stumble. Ripped a few gears and PERMAGRIN is back! My Point I'm slowly learninig the preventive maintenance of the LT5. It's a lot of enjoyment when you start to get the feel of the car and know how to diagnose issues as they come up. Maybe this post will help someone inn the future??? Brett
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1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project Last edited by Blue Flame Restorations; 06-27-2012 at 03:42 PM. |
06-27-2012 | #2 |
Join Date: Dec 2003
Location: Arcadia,OK
Posts: 3,394
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Re: IAC Maintenance
Very good post Brett. Are you using K&N air filter?
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Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 ZR-1, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed. |
06-27-2012 | #3 |
Join Date: Feb 2010
Location: Pendleton, IN
Posts: 3,904
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Re: IAC Maintenance
Hi Jerry. No, I have the SLP three fork system right now. I plan on changing it to the Copeland open unit soon though.
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1988 KOH Prototype EX5023 sold 1990 ZR-1 #444 Convertible 1990 ZR-1 Black #966 1991 ZR-1 Quazar Blue #296 1957 Duntov SS Project |
06-27-2012 | #4 |
Join Date: Jan 2009
Location: Portland Oregon metro area (Washington side)
Posts: 3,207
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Re: IAC Maintenance
FYI . Way back before the forum when there was only an email list the issue of IAC cleaning came up multiple times. The gist of the experts was not to clean the IAC too thoroughly. There is a special grease used on them that needs to stay (same grease used on the TB plates). Since that time whenever I've cleaned it (every 4yrs) I always clean just what I know to be carbon. The area in the crevices by the shaft I leave alone.
Each to his own though. An important area to get is the "in" and the "out" to the IAC on the TB.
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Scott Vett owner since 1979._It's about the car and the people |
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