I was holding my rpm at 1800 then mashing the gas to WOT (this is all while the car is in park.) The engine stutters at about 3500-4000 rpms for less than a second then takes off. If I mash it from a dead stop it kind of winds up then once it hits 2000 it will take off up to 5000 with little to no hesitation. The hesitation from a dead stop is because of the duration in my cam (at least that is my guess.)

I am running a holley 700DP with 27 primary and 35 secondary squirters, not sure on jetting I will have to check my records, I know it is jetted close most likely a little fat.

Thanks,
Chas

 

No one has any ideas?

 

A few...

1) Does the primary squirter fire out gas with the slightest touch of the throttle? It should. If it doesn't, check to make sure that the pump arm is adjusted correctly and that the spring on the pump arm isn't compressing instead of the arm compressing the pump diaphragm.

2) The primary squirter seems small for a performance application. I think I have 35/35 in mine. Up the primary to see if it helps.

3) What is the timing curve like? Mechanical advance comes in when? Do you run vacuum advance?

4) Fuel pressure steady and high enough?

5) Float levels high enough?

6) Lastly, if none of this helps or solves the situation, I would look at the Air bleeds. Maybe one is bocked and not allowing a circuit to turn on in the carb.

 

The primary does squirt at the slightest touch of the throttle (that was my first thought and it did need to be adjusted.

It originally had a larger 37 squirter but ran like crap with the 37.

Timing is full out at 2000 and is ~38* total (I don't have timing tape on the balancer anymore), Yes I am running the vacuum advance. I plugged the vacuum advance to see if that helped and it didn't make a difference.

Fuel pressure is good and holds a steady 7psi.

Not sure about the air bleeds I haven't checked them yet.

Forgot the floats but they are set so fuel just starts to come out when you bump the car.

The hesitation is after the primary and secondary are fully open almost like it runs lean for a fraction of a second then finishes dumping fuel. I don't seem to notice it when I am driving but I can't really tell right now. The roads are to wet to hammer down on her (I went sideways at 70 mph on monday trying to merge onto the highway scariest thing ever, the worst is my car has a open rear.)

I will try the larger squirter and maybe the power valve. Could it be the jetting as well?

 

If it is only doing it at WOT and the throttle is moved enough to open primaries and secondaries, I would be looking at the power valve. Your enrichment at this point will be coming through the "Power Valve Channels". If they are blocked/clogged or the power valves aren't working correctly, then the engine is probably going lean.