Hard to start when hot. Please advise.

[billblack]

I have a 383 satellite with a very lumpy cam, single plane Edelbrock RPM manifold, Holley 650 DP and headers.

The car runs fine but it is annoying to start when the engine is hot. It floods easily and the only way it will start is with 10 seconds of cranking and my foot on the floor.

What causes this and how can i fix it?


Regards,

[451Mopar]

What ignition?
Type of fuel pump?
Pressure regulator?

It could be several factors.
pump gas these days is junk for carburated cars. It boil and vapor locks really easy compared to the old leaded fuel.
to cool the carb temp down you can get one of the non-metalic carb spacers, and block off the heat cross over in the manifold with a different manifold gasket.
If the fuel is vaporlocking in the lines/fuel pump, adding a by-pass return to the fuel system helps keep cool fuel moving in the lines, and using a bypass type regulator is even better.
If the engine cranks, and acts like it wants to fire only when releasing the key, the problem may be in the electrical system. I had a problem like this and it ended up being bad battery cables. Resistance in the ground cable when it was hot, reduced the voltage at the ECU to only about 6-volts and the ignition din't want to fire untill I released the key which removed the high current load of the starter, resulting in full voltage to the ECU.

[billblack]

What ignition?
MSD6
Type of fuel pump?
Mechanical/stock
Pressure regulator?
N/A


Thanks for the tips

[425W5]

Originally Posted by billblack

I have a 383 satellite with a very lumpy cam, single plane Edelbrock RPM manifold, Holley 650 DP and headers.

The car runs fine but it is annoying to start when the engine is hot. It floods easily and the only way it will start is with 10 seconds of cranking and my foot on the floor.

What causes this and how can i fix it?


Regards,

Check your float level on both the front and rear bowls check your initial timing also if you have the old style starter I would change it to the mini style starter.How lumpy is the cam?What are the specs of the cam?

[ehostler]

Too much advance is the primary culprit of this kind of problem. It could also be the starter motor. The third option is that fuel is leaking out of the carb into the intake and flooding the engine.

[billblack]

I don't know the specs of the cam.

Initial timing is ~ 12°, hard to tell though because the advance springs are so freakin light all the advance is in by ~ 1000 rpm. So even at idle, the timing is already into it's mechanical advance curve.

Thanks guys so far for your input

[65TerrorCuda]

I'll bet it's the carb.
My holley is doin the exact same thing since the weather turned warm. Here's what I tried: park the car, let it cool, pull the bowl plugs and look inside the fuel bowls to see if the level has dropped. The front bowl on mine leaks somehow into the engine, it's not the gaskets. Any holley gurus out there?

[coupe32]

Check the timing.

[John Kunkel]

Holleys are notorious for leaking gaskets between the metering plate(s) and the main body. A small amount of leakage will go unnoticed when running but after shutdown fuel will drip into the intake and cause a flooded condition on hot restart.

[TK]

Put a phenolic spacer under the carb, if there is room.
Pitch the Holley.....oh, uh , sorry, LOL.

I have a radical 318, that does the same thing. It idles cool enough, that I give it a quick "vroom" and shut the key off when it is at the top of the "vroom". It seems to help clear the gas elft behind from the long cam duration not burning all of the fuel.
If your engine is hot, it may diesel if you try that, however.

It has cam, but does it have compression? It also sounds like a bad case of over cam, to me.

[billblack]

Thanks all.

I'll look for the flooding after sitting.

Regards,

[dsburch]

I have the HOW to Start tag for my 73 small block. Even in 73, the fuel and vapor locking were known Mopar issues. The warm starting procedure, from the factory, said OPEN THROTTLE SLIGHLTY. This feeds air to the engine to overcome the vapor lock without flooding. The spacer approach to cooling the carb is marginal and may rise the carb too much, causing a number of issue like surprise hood bugle, throttle cable misaligned, etc. The best route is the heat crossover block off. Let her warm up, and you'll never notice a diveability issue.

[crisser]

[QUOTE=451Mopar;680250]What ignition?
Type of fuel pump?
Pressure regulator?

It could be several factors.
pump gas these days is junk for carburated cars. It boil and vapor locks really easy compared to the old leaded fuel.
to cool the carb temp down you can get one of the non-metalic carb spacers, and block off the heat cross over in the manifold with a different manifold gasket.

451 is right. Pump gas really sucks now. A lot of carbs down here are shooting gas out of the bowl vents lately. The weather has warmed and i guess they haven`t changed over to the "summer" blend yet. This only happens after the engine has warmed and has been sitting for a bit. You go back and it runs like $hit.

[billblack]

All,

Forgive my ignorance, but what is a "heat cross over" in the manifold? I infer from reading your posts that this is something that apparently can be blocked with a gasket. I also guess that if I block it off, my car takes longer to warm up. Yes?


How can I tell right now if it is blocked or not? Car is not stock, has edelbrock single plane rpm manifold and aforementioned holley dp.

Thanks,

Bill

[65TerrorCuda]

Heat cross over or heat riser is a passage that allows exhaust gas to heat the intake manifold. Great in winter, sucks in summer.
Performance type intake manifold gaskets like the fel-pro have the passage blocked.
I think this crap gas is a conspiracy to give us carb guys headaches to cave in and buy a new car...

[wilks3]

Take the intake back off, put Felpro or any hi-po intake set that blocks off the heated crossover. Then either buy the Edelbrock insulator carb gasket (.320 thick) or take your carb and go uptown to the "good" autoparts store and have them find you one. Lastly, buy and use Marvel Mystery oil in the gas as directed on bottle. My .060 over 440 had the same problem, did all the above and problem gone.

[Dick]

I don't know if this would work on your engine but I recall that there were some Mopars that had a foil covered insulating bag that fit between the intake manifold and the valley cover. I don't know what years or what engine, although any engine to benefit from this would need a spider manifold and a separate valley cover rather than a one piece manifold/valley cover.

[John Kunkel]

The foil bag used on some BB's was strictly for noise insulation, many believe it actually makes the intake manifold hotter by blocking air flow beneath it.

[Dick]

Originally Posted by John Kunkel

The foil bag used on some BB's was strictly for noise insulation, many believe it actually makes the intake manifold hotter by blocking air flow beneath it.

Thank you John for clarifying the purpose of the bag.

[sundrop_440]

there has been alot of good suggestions, I'll throw a couple more that might save you, what kind of water temp are you running at, if you can keep it under 190 that is going to help the percolating of your carb, under hood temps can really be a problem, an electric fan on a temp switch wired direct to the battery will help reduce the under hood temps alot and they usually only cycle for about 10-15 min. before completely shutting off after you shutdown,it works for my 68 charger, do you have a hood scoop or opening in the hood that can help to,but for many, who wants a hole or scoop when your trying to look stock, wrapping the headers with exhuast tape helps alot also, but for some it doesn't look good, but it will help,and finally check the fuel pressure, I have a carter high pressure mechnical fuel pump, great pump but it pushes at about 9psi and when I installed a regulator down to 6 1/2 it helped, those high pressures really strain the needle and seat in your carb. I hope this all gets you on right path to good running,Sundrop.

[DerbieDriver]

Yeah check to make sure you are not dumping too much gas in by adjusting the screws on the carb.

[DerbieDriver]

You probably also want to check to make sure you choke is working

[pishta]

Electric fuel pump. Sticking distributor advance.