Fuel System: 62 Hawk Runs a while, stalls for 5 min +-, restarts for another 5

[Ted Johnson]

I have a beautiful restored '62 Hawk GT with original Stude 289, Edelbrock carb and electric fuel pump added. Inline sight-glass fuel filter new. Air filter element with chrome top and bottom, naked sides. For the last few days the car will start fine, run about five minutes just fine, stalls, then after about 5 minutes will re-start, etc. Will idle indefinitely. I am getting fuel, have a new fuel filter, no fuel leaks, heat-insulated fuel line near the engine. What could my problem be? I hate not being able to drive on IDYSD! Any advice?

[rusty nut garage]

was the electric fuel pump recently added? What type of electric fuel pump? Do you also have a engine driven pump?

[StudeRich]

To eliminate the Fuel System, I would check for a couple squirts of fuel in the Primary Carb. throats WHILE IT IS DEAD.

If that checks out the Coil may be suspect, is it Hot to touch? Original or newer "Flamethrower I " from China known for failure?

[6hk71400]

2 Cents. Any rubber gas line in the system is suspect to me. All it takes is a very tiny almost not visible pin hole that when it gets warm will open up and cause the car to stall. It will idle all day but when fuel is demanded, the gas will take the path of least resistance, out the hole. A rubber hose may look good but if you have not replaced all the rubber hoses used in line, maybe that it. Cheap and easy to check out.

Bob Miles
Tucson AZ

[Ted Johnson]

Thanks for responses. Yes electric fuel pump is after market and recently replaced. No active engine driven pump. I do have some rubber fuel lines. No apparent leaks Aren't there any that are reliable?

[sweetolbob]

Thanks for responses. Yes electric fuel pump is after market and recently replaced. No active engine driven pump. I do have some rubber fuel lines. No apparent leaks Aren't there any that are reliable?

If you mean reliable rubber lines, then the answer is yes. Just purchase the ones rated for fuel injection use. Made to handle way more pressure and the newer fuel types. A bit pricey, relative to the cheap cr@p, but it's all I use now.

Bob

[rusty nut garage]

start with coil mentioned above.
the reason I asked on the electric fuel pump, if you were running a engine driven pump as well, they won't suck through the gearotor design pumps. The pulse diaphragm pumps will work with a engine driven pump.
Is the electric pump mounted close to the tank and lower then the pickup at tank. The electric pump will push fuel better then it will pull fuel. If your asking it to pull fuel and you have a pinhole in line prior to pump it will pick up air and not pump fuel. If you have a pinhole downstream from pump you should have a leak. a fuel pressure gauge mounted where you can monitor it when the car quits will be helpful. As always when dealing with fuel and testing be careful with leaks while driving and testing.

Thanks for responses. Yes electric fuel pump is after market and recently replaced. No active engine driven pump. I do have some rubber fuel lines. No apparent leaks Aren't there any that are reliable?

[karterfred88]

Runs fine at idle--for how long? If forever, and quits after being accelerated, or driven some distance, I'd aim at "fuel supply". Perhaps collapsing of hose into the fuel pump, cutting off supply, a clogged screen in the tank inlet slowing fuel delivery. Drive, let stall, and immediately run, open hood check the filter for fuel level at that moment. Or put a fuel pressure gauge you can read from inside car, immediately before the carb inlet inline. While a coil is a possibility, most coils I've replaced were never good for 5 minutes, then bad, and then worked again! However, a carb that gets drained and stalls the car, can refill and run the engine for a long time at minimal fuel delivery, just not under use that depletes the bowls faster than they are filling up. Also the opposite can occur, too much fuel, running over the bowl tops flooding the engine, sitting lets it dry out and it restarts and if the inlet needle is able to control the flow at a low pressure it will run fine, till pressure overcomes the needle and seat and starts the process over. If possible, if the bowl of the filter looks full when it stalls, pull first available spark plug and check for wetness as a sign of flooding out. If its wet it's time to dig into the carb-- possible a dirty or damaged inlet needle might be all that's wrong, or a bad float. Good luck.

[6hk71400]

Thanks for responses. Yes electric fuel pump is after market and recently replaced. No active engine driven pump. I do have some rubber fuel lines. No apparent leaks Aren't there any that are reliable?

A small pin hole will not be apparent and drive you crazy! I went through this on a great running 1956 President Classic that did not have an electrical pump but had both a pin hole and possible collapsing rubber line. Went to my FLAPS, replaced the rubber hose(s). No more problem even in summer driving with trunk mounted Studebaker A/C. Now I advise everyone to replace the rubber fuel line hoses every couple of years. The hoses don't seem to age well with our current gasoline.

Bob Miles
Tucson, AZ

[kurtruk]

Does this car need a vented gas cap? Does it have one?

[Warren Webb]

Does this car need a vented gas cap? Does it have one?

This was the first thought that came to me before I read any of the other responses. I'd remove the gas cap & take it for a drive staying nearby & see what happens. I don't believe I've seen an in-tank fuel filter in a Studebaker but the electric pump should be mounted as close to the tank as possible. I've experienced the cheap fuel hoses for the past few years & opt to the fuel injection hoses as Bob Miles recommended.

[JoeHall]

After it sputters and dies, turn the key off, look down into the carb, and pump the accelerator 4-5 times. If the accelerator nozzles are spraying gas, the carb did not run dry, so starvation is not likely the problem. OTOH, if the nozzles are not spraying, that is exactly what it is telling you (bowl is dry). If dry, could be fuel supply, somewhere between the tank and the carb inlet valve.

If the bowl is not dry, it is likely flooding due to: floats set too high; floats dragging on the sides of the bowl, or inlet valve sticking.

I am assuming the choke is opening all the way. Yes?

Maybe you have an extra carb to slap on it and see if the problem goes away?

Its easy enough to test the cap vent by just removing the cap.

[Dan Timberlake]

Like others said, as soon as it dies the first thing I'd do is look to see if the carb accel pump squirts when the throttle is open. Pass /fail, with clear direction as to whether there is a fuel delivery problem.

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The second thing I'd do immediately post mortem is test for spark at a plug, and also out of the coil. I recently got one of these.
http://www.autozone.com/test-scan-an...ter/10257_0_0/

Easily One of the best 9 US bux I ever spent. WAY better than the wide gapped new plug test I've used for the last century. The ground clip positions the gap for good viewing and frees up a hand and resists being disturbed by engine motion. The adjustable gap REALLY puts the ignition to the test. The dark colored body shows up the wispy spark of a CDI very well. The tip unscrews to simulate either type of spark plug end.

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If there is fuel in the carb and a good spark I'd be thinking maybe a big droplet or 2 of water is rolling around in the carb covering up important holes.
http://www.flatheadv8.org/Image17.gif

I like to take a sample of fuel in a clean pyrex cup from the fuel line disconnected at the carb, after the final inline filter while cranking. If it is anything but crystal clear it suggests water contamination. A splash of isopropyl drygas will prove if the gas was clear, or not. It is still possible all the trouble is in the float bowl.


Sprinkle some water and some gasoline on two separate clean surfaces to see how the droplets form. Water droplets look like jabba the hutt.
One of the few times (but becoming MUCH more common in the era of ethanol laced fuel) a bottle or 2 of isopropyl dry gas earns it's keep.
Briefly covering the carb throat while revved in neutral can sometimes clear the clogged jet.

[JoeHall]

I am also assuming it has clean, fresh gas, from a clean tank? Varnished gas will gum up the motor so bad it will need to be disassembled in order to get the gum off the rings and valve stems.

[SN-60]

I'll never understand why folks shy away from the reliable Studebaker mechanical fuel pump and INSIST on wiring the car up for an electric fuel pump.

Sorry, but to me, it's like trying to re-invent the wheel. (IMHO)