Idle trouble
Thread Starter
Burning Brakes
Joined: Aug 2001
Posts: 1,060
Likes: 33
From: Eagleville PA
Idle trouble
I'm having Idle trouble with my 79. The carb is the stock quadrajet. When warm, it was running at 900 in park, and 400 in drive with the brake on, but the engine wanted to cut out. So I bumped it up to 1300 when in park, which now runs at 600 when in drive with the brake on. It doesn't want to cut out when stopped with the brake on anymore, but now it runs for a little bit after I turn the key off, and the park/idle sounds is really loud and seems too high.
My questions are these:
1) Is there only one idle adjustment screw?
2) Should there be such a great difference between the park/idle speed and the drive-stopped/idle speed?
3) What can I do to get it to idle properly?
** UPDATE 11AM 11/5 **
I found a vaccum leak... pretty obvious one. It run from the engine to the fuel vapor canister. It was laying on the exhaust manifold so it burned and split apart. I fixed that hose and turned the idle down. It now runa at 600 in park and 400-500 in drive. But now the GEN light comes on while idling stopped in drive. Should I crank the idle back up 100 or 200?
Thanks in advance!!
[Modified by adamw1979, 11:02 AM 11/5/2003]
My questions are these:
1) Is there only one idle adjustment screw?
2) Should there be such a great difference between the park/idle speed and the drive-stopped/idle speed?
3) What can I do to get it to idle properly?
** UPDATE 11AM 11/5 **
I found a vaccum leak... pretty obvious one. It run from the engine to the fuel vapor canister. It was laying on the exhaust manifold so it burned and split apart. I fixed that hose and turned the idle down. It now runa at 600 in park and 400-500 in drive. But now the GEN light comes on while idling stopped in drive. Should I crank the idle back up 100 or 200?
Thanks in advance!!
[Modified by adamw1979, 11:02 AM 11/5/2003]
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: Idle trouble (adamw1979)
1300 in park for a stock engine is way too high. Then when you hit drive or step on the brakes it drops or stops. Mostl likely a vacuum leak somewhere. Get a gauge and see what your vacuum is at idle. You should be pulling about 17-18". Idle it down to 800 in park to check. Then leave the gauge on and see what your reading is in drive. Should not drop below 15". Now step on the brake and see if it drops beelow 15". If so, your booster may have a leak.
What is the timing set at? For a base engine look at your decal and make sure your timing is set to spec to start with.
As far as idle adj. goes, there is only one screw on the throttle arm with a big spring on the drivers side. The idle solenoid should only affect it when the AC is on. The mixture screws will affect idle but not from 800 to 1300.
I don't think you have the E4MC carb in that year. If you do then there are bunch of things that come into play. Tag us back.
What is the timing set at? For a base engine look at your decal and make sure your timing is set to spec to start with.
As far as idle adj. goes, there is only one screw on the throttle arm with a big spring on the drivers side. The idle solenoid should only affect it when the AC is on. The mixture screws will affect idle but not from 800 to 1300.
I don't think you have the E4MC carb in that year. If you do then there are bunch of things that come into play. Tag us back.
Thread Starter
Burning Brakes
Joined: Aug 2001
Posts: 1,060
Likes: 33
From: Eagleville PA
Re: Idle trouble (adamw1979)
** UPDATE 11AM 11/5 **
I found a vaccum leak... pretty obvious one. A hose that runs from the engine to the fuel vapor canister. It was laying on the exhaust manifold so it burned and split apart. I fixed that hose and turned the idle down. It now runa at 600 in park and 400-500 in drive. But now the GEN light comes on while idling stopped in drive. Should I crank the idle back up 100 or 200?
I found a vaccum leak... pretty obvious one. A hose that runs from the engine to the fuel vapor canister. It was laying on the exhaust manifold so it burned and split apart. I fixed that hose and turned the idle down. It now runa at 600 in park and 400-500 in drive. But now the GEN light comes on while idling stopped in drive. Should I crank the idle back up 100 or 200?
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: Idle trouble (adamw1979)
Great, found a hose off. Set the idle at about 800 in park and you should have around 600-650 in drive. As far as the light on = check to see if the alternator belt is loose. If should deflect no more than the thickness of the belt. Idle at 600 and a tight belt should fix it.
