Mechanics

FORD F-350 RPM PROBLEM

1993 Ford F-350 • 10,000 miles

I have a f350 with 351w standard trans I had edelbrock fuel injection with 24lbs injectors could never get it to tune. Pulled it all off replaced with edelbrock victor jr intake, BIGS carb jetted 800cfm, msd 6a, fuel regulators, and pushing 40psi intake fuel pumps. My fuel pressure gauge is all over the place, had to retard my timing to 5 btd to get it to stop deiseling, and when I adjust my air fuel at an idle runs great tell you try to drive it, starts to back fire and acts like its running out of fuel, so I idle it up to 2000rpm reset floats, drove again did same thing except now the fuel pumps are pushing past my regulators and over running the floats Do you have any idea's


Thank you for you response, I have a high dollar regulator on it thats suppose to be able to handle the fuel injection pumps that are in the tank and keep the pressure at 8 lbs witch is what the BIGS carb needs and it does have a return line, all the work on the timing was done with the idle around 800 rpm, I started at 10, set the carb but was dieseling, played with it over and over and ended up at 5 degrees with an idle of about 750-800, tuned in the floats in the shop it sounds great you could hold the Rpm up, rack it, but as soon as you try to drive it it goes bad, it would go maybe 50 yards and start acting up, I cycled the key three times to let the fuel pumps refill the bowl and it would go again for about 50 yards that's why I held the rpm at 2000 rpm and reset the floats only but no change, I'm starting to wonder if the msd system is acting up or if the distributor is not advancing or the plus sating fuel injection pumps can't keep up with the demand of the carb
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Nate2084
March 1, 2013.




Put the timing back to correct specs. Dieseling comes from the carb not timing.

The fuel pressure needs to be 8 lbs, no more.

The carb needs to be set up so the idle is low enough that the throttle plate is closed at idle. That will stop the dieseling.

Roy



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