Need help. Possible tune issue???
Thread Starter
Drifting
Joined: Dec 2000
Posts: 1,785
Likes: 91
From: Leander TX
Need help. Possible tune issue???
I have an 81 with an edelbrock perormer intake and carb. Car has a gm 350 crate motor as well. It seems to drive good but the car wont stop Dieseling plus I just finished my first tank of gas since the intake and carb and I got right at 8-9 mpg. Car is a 4 speed.
I have the base timing at 8 BTDC and the carb hasn't been touched since taking it out of the box (they said it was tuned from the factory). Car no longer has the EGR or smog pump but has everything else in stock form.
By Dieseling I mean running forever without stopping. Today I waited 10-15 seconds before I just put it in gear and let off the clutch to get it to stop. Sometimes when it stops it make a noise like a womans sigh when they are mad (hope you get the sound I'm trying to describe) at you... At least my wife
Any idea on what I can do to get some MPG's and stop the Dieseling? I understand it is an old carb car but was thinking that I'm getting big block MPG with a base 350.
I have the base timing at 8 BTDC and the carb hasn't been touched since taking it out of the box (they said it was tuned from the factory). Car no longer has the EGR or smog pump but has everything else in stock form.
By Dieseling I mean running forever without stopping. Today I waited 10-15 seconds before I just put it in gear and let off the clutch to get it to stop. Sometimes when it stops it make a noise like a womans sigh when they are mad (hope you get the sound I'm trying to describe) at you... At least my wife
Any idea on what I can do to get some MPG's and stop the Dieseling? I understand it is an old carb car but was thinking that I'm getting big block MPG with a base 350.
Le Mans Master
Joined: May 2002
Posts: 5,086
Likes: 786
From: Lebanon Township New Jersey
Dieseling is usually caused by timing or idle speed.
When you set the timing at 8 deg, was the vacuum advance disconnected? It should be. Reconnect when done and set the idle speed to a minimum level needed to keep running.
When you set the timing at 8 deg, was the vacuum advance disconnected? It should be. Reconnect when done and set the idle speed to a minimum level needed to keep running.
Thread Starter
Drifting
Joined: Dec 2000
Posts: 1,785
Likes: 91
From: Leander TX
Idle speed was set at 700-800 rpm so it would idle good with the AC on. On the way home last time I drove it the car stayed at 1200-1300 for some reason. Thinking it may be due to me fixing a previous vacume leak so I was going to hit that again. Do you think this would cause the MPG's to be so bad too?
