Vehicle hesitates and cuts out at 3K rpm under hard acceleration

[clintmopar]

Hope that you can give me some help. I have plugged my vacuum advance and changed my orange box and I am still having a bad hesitation and it cuts out. When it occurs let off the gas and feather the gas and it runs fine again. Happens worse on hard off the line acceleration. I have a 68 Road Runner with a 383 and auto trans. Has a Mopar Electronic conversion ignition with orange box, eddy 750 carb, headers, small thumper cam, stock fuel line, pump and filter. Wondering if I have a ignition or fuel problem?

 

[Lionized]

What do you mean by "plugged"?

 

[Hemi Rebel]

Sounds like fuel to me. Has non stock cam, carb and exhaust. With stock fuel system.:gah:
weak/bad pump and restrictive filter could be it.

 

[clintmopar]

Vacuum ports on the advance and the carb.

 

[clintmopar]

Thanks

 

[mopar 3 B]

If you have a tack installed does it gain or lose rpm when this occurs?

 

[clintmopar]

It looses rpms and surges.

 

[glassman]

My old 62 Savoy afb used to do this. I would hange the accelerator pump in the carb and all would be fine.

 

[WP29440SE]

I would check fuel pressure and float levels for starters

 

[mopar 3 B]

It looses rpms and surges.

Fuel problem. If you had a bad coil rpms would increase.

 

[kdtjb]

Try putting some more timing in it, Then see what it does. I changed mine from 12 to 18 initial, made a big difference.

 

[mopar 3 B]

Try putting some more timing in it, Then see what it does. I changed mine from 12 to 18 initial, made a big difference.

I do not think he has enough cam to justify anything over 12. Also he needs to hook the vacuum advance backup and check for proper operation first. Will need a timing light and tach. 18 degrees initial will work the heck out of the starter on hot starts and I have found no justification for it with the type of ignition he is running if everything in working like it should.

 

[glassman]

With all of these ideas, he should have it fixed in no time and I am real curious to see what the actual problem really was.

 

[lewtot184]

stock fuel pumps are 3-5lb pumps and most won't make 5lbs. and, to add to the misery folks will put a filter on the suction side of the pump. this is the first i'd look because it sounds like fuel starvation.

 

[coloradodave]

With all of these ideas, he should have it fixed in no time and I am real curious to see what the actual problem really was.

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