Alright guys, let me pick your brains. You've helped me out before when I ghost the forum so hopefully this will work.

I have an 86 Z28, originally with the 305 4bbl carb, vin H. The engine in it now is a 350 4bbl Holley, 600-700cfm (not positive) with a street dominator intake. T-5 transmission as well. There is no more computer in the car.

The automatic choke on the Holley has always given us trouble, and never worked. I assume this is because the P.O. hooked up the bimetal with a hot 12V wire, burning it out or something.

The car has a manual fuel pump in the engine bay off the block. I have heard that these cars do have electric fuel pumps in the gas tank, but I am not sure if it is working because the missing computer.

I have an MSD ignition, 6A box and a blaster 3 coil.

Within the last month or two, the car starts great with 2 or 3 pumps of the gas pedal before cranking when COLD.

There are two issues I am having. After it has warmed up, say at 160* and up, while braking (clutch in) the rpms drop down to 750, and if it's a hard stop, it can stall sometimes. While I'm stopped at a stoplight, the idle goes up to 1200. Before my idle was set to about 800 when hot. Moving the idle screw out does nothing to lower the idle.

Also, If it doesn't sit for a few hours, the engine has trouble starting. It cranks at a normal speed (hopefully eliminating starter heat soak), but does not fire up without pumping the gas a lot. I also noticed yesterday that holding down the pedal all the way so the throttle is 100% got it started, albeit still slower than a normal firing up.

We replaced the coil assuming it was heat soak on that, and even relocated it far away from the engine, and that did nothing.

We have a few theories right now, such as the choke closing and flooding the carb, or vapor lock.

I am sort of confused on the vapor lock because it has not done this since we bought it, only recently, and we've never changed the gas line routing.

Sorry for the long winded post, hope its readable, and hope you guys can help me out with this one.

Thanks everyone!

Jake

EDIT: Also, the charcoal canister is not hooked up. Something we have not fixed from the P.O. yet

 

If I were an expert, I'd have my own fuel issues solved, but what comes to mind is...

Holding the pedal down all the way to start it is telling you it's flooded perhaps - that's how to start a flooded carbed car. Maybe floats need adjusted in the carb.

 

The majority of the time when a car stalls form using the brakes, it a vaccum leak problem, as the brakes use so much vacuum, if there is a leak, it will suck the life right out of the engine.

 

Whats your initial timing?

 

Not sure on my timing at the moment. However I did notice that my secondaries were dripping a little heavy with the car on, and when I shut down the car, the secondaries continue to drip for about a minute. I assume this is where the flooding is coming from. I'll get back to you guys when I pull the carb apart to check out the needle valve.

 

UPDATE: Took the floats off the carb, there was a metal chip () stuck in the secondary needle valve, so after doing that it works great. I messed with the floats a little bit to see if I can get them on right.

Now the car starts with 3 pumps of the gas (no choke), idles high, then dies.

Also, I heard a whistling sound the first few times I started it after putting the carb back on. I kind of think this is from the mounting bolts not being tight or even.

I'm thinking I need to set the floats higher and the accelerator pump to hit sooner.

 

RESOLVED.

Floats set, accelerator pump and cam set. starts, idles, accelerates. Problem solved. If you are having a hard start when hot, check to make sure your secondaries (or primaries). They could be leaking into the carb. Good luck all