Engine revving high in park
Thread Starter
2nd Gear
Joined: Aug 2012
Posts: 2
Likes: 0
Engine revving high in park
Hey guys, I'm new to posting to this forum and have looked for the answer to this but haven't had any luck yet. I got a problem when I start my 79 up it revs up pretty high but when put in gear it runs normally. Anybody else ever have this problem? Also, my exhaust on right side blows cold air (did the paper trick and it did not pass needless to say) but the plugs seem to fire just fine. Any help here would be GREATLY appreciated.
Burning Brakes
Joined: Oct 2001
Posts: 1,241
Likes: 4
From: Okinawa Okinawa
I'm guessing it does not only run at a high RPM on the first start up which would indicate an adjustment needs to be made to the choke. Have you set your timing and idle correctly?
Is the right side manifold hot when the car is running?
Is the right side manifold hot when the car is running?
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Sounds like the heat riser valve on the passenger side is sticking closed. What's interesting is that it the passenger side showed no air, so if my theory is correct that would also assume the vehicle has true dual exhaust with no crossover pipe... does it, and is the heat riser valve present?
Instructor
Joined: Apr 2011
Posts: 217
Likes: 0
From: Shearwater Nova Scotia
What exactly is high RPM? If it runs at 1600 from a cold start then you are spot on (if I remember the idle settings correctly). Once you are in gear you should be about 650. Curb idle is about 1150 (?) I think - all these settings should be in the owners manual.
IF you are still high in RPM, below the choke adjustment there is a little screw whose head is facing the front of the car. This is the fast idle adjustment screw. When the car is cold, start and adjust this screw to get the idle you want.
You only get a couple of cracks at this per day. Once the engine is warmed up - adjusting that screw won't do you any good.
There are some YouTube clips showing the works of a QJet - look them up and get familiar with the parts. If you are anything like me, you can read this stuff till your eyes bleed - but you need to see it to understand.
IF you are still high in RPM, below the choke adjustment there is a little screw whose head is facing the front of the car. This is the fast idle adjustment screw. When the car is cold, start and adjust this screw to get the idle you want.
You only get a couple of cracks at this per day. Once the engine is warmed up - adjusting that screw won't do you any good.
There are some YouTube clips showing the works of a QJet - look them up and get familiar with the parts. If you are anything like me, you can read this stuff till your eyes bleed - but you need to see it to understand.
Thread Starter
2nd Gear
Joined: Aug 2012
Posts: 2
Likes: 0
I havs not checked the manifold yet and it is a true dual exhaust with no crossover. Where would that valve be? I dont really hav that extenaive knowledge of things besides how to change plugs n wires 
i will try that screw after work today and see if itdoes the trick
i will try that screw after work today and see if itdoes the trick
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
The heat riser valve should be connected to the passenger side exhaust manifold.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
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From: At my Bar drinking and wrenching in Lafayette Colorado
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