I rebuilt my 360 AMC, have gone through everthing with quality parts, but between 55mph-65mph it begins to backfire and sputter and wants to die unless I let off the gas. I've tried two different new carburetors, and even put a new MSD iginition system on it to replace the old Ford setup.
2007-02-28 05:18:52 · 3 answers · asked by whisky 3 in Cars & Transportation ➔ Maintenance & Repairs
The intake(four barrel edlebrock aftermarket) is not leaking and vacuum is excellent. It only seems to happen off line when I punch it and the secondarys are open going into third gear. If I gradually cruise up to 60 mph there is no problem. Also, the fuel pump is brand new, and seems to deliver fairly well at idle, at idle the engine sounds great.
2007-02-28 07:40:09 · update #1
Did it do this before the rebuild? How's the fuel pump delivery? At idle, with the fuel line going into a can, you should be getting about a pint in thirty seconds. It sounds like fuel starvation to me. What does the engine vacuum look like? Are you dead certain that the intake manifold isn't leaking air somewhere. Go around the gasketed area with a can of carb cleaner and a leak will show up as an increase in r.p.m. What type of fuel filter do you have. Is it new? Also, a vacuum leak in the advance line could be causing a loss of timing under load. Good luck.
2007-02-28 05:37:10 · answer #1 · answered by lurned1 3 · 0⤊ 0⤋
Is either a timing issue or something is wrong with the EGR system, as both can cause a backfire.
2007-02-28 13:50:15 · answer #2 · answered by gary o 7 · 0⤊ 0⤋
Check the timing?
2007-02-28 15:43:55 · answer #3 · answered by ? 4 · 0⤊ 0⤋