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Strange idle issue

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Old 11-11-2012, 09:22 PM
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sundog
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Default Strange idle issue

Well, I think I did something, but can't figure it out.

I was tracking down my injector issues, and took them all out, and replaced them. Put the injectors and fuel rails back on and started the car. Worked like a champ.

Then I put back on the blower, and air filter housing. And replaced the heater hose in the left rear wheel well. When I got back into the car and started it, it went right to 3500 RPM. I can go back and force it back to 1000 RPM with the throttle linkage on the engine, but then it goes back to 3500.

I took it for a drive, and thought that might sort it out, but no luck. Messed with the Cruise Control, but that didn't seem to have any effect.

Anybody have any ideas where to look?

1991 C2 with Tiptronic.
Old 11-11-2012, 09:43 PM
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Rocket Rob
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If you had the injectors out, could you have an intake air leak? That would cause a high idle.
Old 11-11-2012, 09:49 PM
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Originally Posted by Rocket Rob
If you had the injectors out, could you have an intake air leak? That would cause a high idle.
I don't think so. I can bring it down by pulling the throttle back in contact with the idle switch.

Where does the throttle cable run? Maybe I pulled that while putting in the heat hose.
Old 11-11-2012, 10:05 PM
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Rocket Rob
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Not sure if there is any differences in the routing on a car with a tip. On the manual cars, the throttle cable routes from the butterfly down through the tin at the back of the engine. The cable is then attached to the side of the tranny at the top of the diff side cover. It then goes to a tube in the central tunnel.

Did you remove the intake plenum when you were pulling the injectors?
Old 11-11-2012, 10:10 PM
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Originally Posted by Rocket Rob
Not sure if there is any differences in the routing on a car with a tip. On the manual cars, the throttle cable routes from the butterfly down through the tin at the back of the engine. The cable is then attached to the side of the tranny at the top of the diff side cover. It then goes to a tube in the central tunnel.

Did you remove the intake plenum when you were pulling the injectors?
Nope, just the air box cover. It was running fine with it off..
Old 11-15-2012, 03:49 PM
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OK, so I diagnosed and fixed it last night.

The issue was that when I was replacing the heating duct in the right rear wheel well, I must have moved the throttle cable out of the way. When I checked the throttle cable mount back behind the throttle body, the sheath around the cable had come out of the boot that terminates and holds the end of the sheath. So, all I had to do was cut the hell out of my hand getting it back in the space, and realign the throttle cable into its termination. Problem solved, and only required 2 bandaids.
Old 11-15-2012, 03:55 PM
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Rocket Rob
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Glad you got it resolved. I can relate to needing bandaids. My GF always laughs when I work in the garage and come in with cut hands. She give me a hard time about not working if I come in without a cuts. I prefer using superglue instead of bandaids for most cuts.



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