I can’t make a good run at the strip. Symptom is surging
from the almost from the time I leave the line and won’t run past 3-3,500 rpm
or so. Fuel pressure drops from the recommended 6.5 to 3.5 psi. Engine will usually
cut off down track like it’s out of fuel. I can eventually restart it.
Sometimes it runs enough to get me off the track, again, at the reduced rpm,
other times, it stalls out again and can’t be restarted till I get back to the pits.
This engine and carb made 500 HP on an engine dyno and hasn’t been messed with
since then.
I gone completely though the 3/8” fuel system from the
pickup to the regulator. Was pumping 100 gph out of the pump, 80 gph just
before the regulator and 45 gph at the carb – I upgraded the regulator as a result
of that to no avail. I added filters 9 a 100 micron filter before the pump and
a 40 micron before the regulator.
We did notice that the electric fuel regulator would take 30
seconds or so to get to full pressure or 6.5 psi and did it in spurts. The mechanical
gauge on the regulator was very slow to react. Based on that, our guess at this time is that the Carter P4600 fuel pump is
worn out. The fuel pump I don’t have a spare and I’m hesitant to throw money at the thing and buy another pump without some more rational reason.
We also think that the carb needs rebuilt/replaced. I have a 750cfm Edelbrock
and an 850cfm AED Holley that we will try next time.
Any ideas ?
Akron Don Gallimore
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