Hi. If there's "pooling" of some fuel in the rear intake manifold "valleys", could that indicate a bad acc. pump?
I have a 1973 mustang with a 351C engine, stroked to 394.6 cu. ins., yielding 500 h.p. and 500 lbs. of torque,
and runs quite strong. There's a quick fuel 750 cfm with manual secondaries carb. Front jets are 72's while the rears are 84's. The power valve is a 6.5 ( it pulls about 12.5 inches at idle.) The 4 squirters atop are all 35's. Carb rums on 6 lbs. fuel pressure. Manual transmission. The secondaries carb linkage is set to a 40% or better throttle, with the secondary "cam" being a "light pink" in the #1 position. When I deliberately "get on it" with a STEADY, interrupted press to WOT, she flies terrifically. But when I "stomp it", there's a split second bogg until it catches up to itself and resumes flight. My exact question is: With noticing some fuel "pooling" in the intake manifold "valley", just below the the secondary accelerator pump, could the "bogg" concern be from a bad secondary accelerator pump, possiblly being revealed by the "pooling? Could there too be a need for a recalibration within the secondary circuit (pink cam and mounting position, jetting, or squirters)?
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Open Oct 09, 2023 - 08:10 AM
Ford
1answer
Answer
Oct 12, 2023 - 02:28 PM
Hi there,
Yes. "Pooling of fuel" in the rear intake manifold valleys indicate a bad secondary accelerator pump. The 2ndary accelerator pump is responsible for injecting additional fuel to the engine when throttle is opened quickly. It helps to prevent the engine from bogging down when accelerating. If it is faulty, it would not inject fuel into the engine. Another cause is clogged or defective fuel injector. A faulty injector may not inject fuel to the cylinder of the engine or spray the fuel to the wrong direction, which lead to pooling of the fuel in the rear intake manifold. I hope this helps!
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