Author Topic: FORD 302 rough idle  (Read 9259 times)

hoagie

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FORD 302 rough idle
« on: August 09, 2008, 09:39:05 PM »
Hello all,
 

I have a 73 302 I'm trying to get running good before I put it in my 67 mustang. It has a rough idle that I can't seem to fix. This is what I did today. I took off the carb and cleaned the spacer and replaced the gaskets "new" replaced the points and condencer. I also replaced the plugs and wires.  I looked at a intact van with a 302 and routed my vac lines the same as the  van. One line from the carb to the front port of the vac adv and the back port of the vac adv to a vac port on the back of the manifold. All with the same results very rough idle and will smooth out if I rev the engine above 2500 rpm's very slow. In gear it will die ( and slight backfire ) with a little gas.

Any help please

Hoagie

66GTKFB

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Re: FORD 302 rough idle
« Reply #1 on: August 10, 2008, 12:00:52 PM »
There are too many variables to contend with when you have a 'rough' idle. Try a vacuum guage to see if you have a steady vacuum. Burnt valves, vacuum leaks, carburator floats etc, are all on the list. First, get a 1967 distributor and get rid of what ever you. That advance-retard distributor is a pain in the ass. 
Jim

Soaring

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Re: FORD 302 rough idle
« Reply #2 on: August 11, 2008, 01:45:56 PM »
Check the compression in addition to the vacuum as Jim suggested.  If one of the cylinders is more than 15% or so lower than the others, more than likely that cylinder has a burnt valve. 

Jeff n Karen Fleetwood

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Re: FORD 302 rough idle
« Reply #3 on: October 12, 2008, 02:45:31 PM »
I would also suggest checking the vaccum line to the transmission (if automatic) sometimes they get brittle, and can crack (weather/age rot) where the line connects to the Vaccum modulator, had this happen on my 1970 302 C4. Fixed the problem with a 3 inch piece of vaccum line, and the transmission shifted better also..

Soaring

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Re: FORD 302 rough idle
« Reply #4 on: October 12, 2008, 06:16:13 PM »
I would also suggest checking the vaccum line to the transmission (if automatic) sometimes they get brittle, and can crack (weather/age rot) where the line connects to the Vaccum modulator, had this happen on my 1970 302 C4. Fixed the problem with a 3 inch piece of vaccum line, and the transmission shifted better also..
Good suggestion.  I sure wish folks would get back to us with how they fixed the problem.  It makes it almost a waste of our time to post a suggestion to cure the problem when we don't get feedback. 

 

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