Vacuum ??'s

94CobraPace · Dec 14, 2005

I rebuilt a 351 W recently & I got it running. It runs OK, not great. Have a Edelbrock carb that was previously on the car & it ran good. When at idle the funes are eye burning real bad. At idle with the digital timing light with rpm, the rpm will flucuate from 700 to 1000, after the the car is reved. I've check all the vacuum lines, didn't see any cracks or leaks.
How to check to see if there is a vacuum leak between the intake & heads?
Any other ideas?

Wootdog · Dec 14, 2005

carb cleaner spay the intake gaskets it will run real rough and spay your lines it works

tos · Dec 14, 2005

Woot is right. spray cleaner around base of carb too, you'll know when you hit a leak. It sounds to me like its running real rich though which would be the opposite of a vac leak although dont rule that out just yet. Are you sure your choke is working and opening up all the way?

jbuening · Dec 14, 2005

Go buy a vacuum gauge from Autzone or your local parts store. I paid $20 and it has saved me many headaches. Post your vacuum reading results here and we can go further. What does the car idle at normally and is the rpms steady?

tos · Dec 14, 2005

Also are you sure your firing order is correct? its different than 289/302.

krash kendall · Dec 14, 2005

Are you using a carb spacer? Are you using a new carb gasket? The edelbrocks can draw fuel from the bottom of the carb, bypassing the idle curcuit, if not seated properly. Again, a spray of something flammable at the base of the carb will make the motor rev if the gasket seal is the problem.

94CobraPace · Dec 14, 2005

I have put a vacuum gauge on it & it was reading a jumpy 16. Yes a carb spacer is being used. RPMs are not very steady, it changes after it is reved. I can set the rpms at 750, rev the engine & when it settles it will be 900 or so. New carb gasket between both spacer & carb. I can change the idle screws & it changes how the car idles & can die when screwed in too much.

HistoricMustang · Dec 14, 2005

tos said:
Woot is right. spray cleaner around base of carb too, you'll know when you hit a leak. It sounds to me like its running real rich though which would be the opposite of a vac leak although dont rule that out just yet. Are you sure your choke is working and opening up all the way?

Keep that stuff away from the distributor!

I use starting fluid....................keep it away also!

HistoricMustang
www.historicmustang.com

krash kendall · Dec 14, 2005

94CobraPace said:
.... I can set the rpms at 750, rev the engine & when it settles it will be 900 or so.

Is this with engine warmed up to operating temperature? Is the vacuum advance hooked up and if so to which port?

94CobraPace said:
....New carb gasket between both spacer & carb. I can change the idle screws & it changes how the car idles & can die when screwed in too much.

This is good. I had a hard time with brand new parts getting those gaskets sealed at the front. Had to really torque the carb bolts.

Vacuum ??'s

94CobraPace

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94CobraPace

HistoricMustang

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