We have tried everything we can think of (including wholesale replacement of parts) and cannot solve the following. Car starts and runs great for a few minutes or about a half mile and then suddenly stops running. It appears to run out of gas but am not sure about that. We have replaced distributor, caps, wires, pump and pushrod. carb. harnesses, resistor, switch, and start relay. You can choke and restart car but it will quit again. You cannot catch it by pumping the gas. We have checked float level and installed carb spacer. None of this has changed or solved the problem. We have an inline electric pump used for start up. I need help.
Might be common sense, but did you clean the fuel tank? Maybe the fuel filter is getting clogged with rust/trash? Posted using the Full Custom H.A.M.B. App!
Yrs ago I had a like problem with my 33 pickup.. Remove gas cap and see if it runs longer.. I had a gas line hose clamp (not leaking ) that caused the problem on top of tank. I had to remove bed to find problem, no problem after that..
Try running it at a fast idle in the driveway and see if it quits. It sounds like either a fuel starvation problem or a coil that gets hot and opens up. My guess would be fuel related.
I had this problem on a Ford F1 truck, it was the gas cap, it let no air in to tank and its building vacum when you drive.When the car had stopp for a minute the vacum is gone and you can start the car. Rickard
Remove the gas cap when this happens and see if it will run. We have seen a couple of tanks collapsed because of bad vent caps. If removing the cap doesn't allow it to run, loosen the line at the carb and see if fuel is getting there while cranking.
You say you have an inline electric pump for start up! What happens to the electric pump after you start the car? simple check, after stopped pull the carb covers and check for fuel by looking for accelerator pump and see if it is afuel problem, namely no fuel in carb. If fuel in carb it is electrical. pull sparkplug and check if sparking when cranked., If sparking, check for a bad coil that is opening up after the coil gets hot. And then pull gas line and see if the electric pump will pump a gallon of gas a minute. Not on the floor , but in a gas can. LOL Some times the electric pump may have a shut off if the gas is not re-circulating back to the tank.
thinking a little more, it seems you have an inline electric pump, but you say you replaced the pump and pushrod, which seems to indicate that you use the electric pump to get gas to the regular pump to start the car. Now, an I am guessing because I can not see what is being done, the regular pump uses a vacumn to pull gas out of the tank and if you are putting pressure into the regular pump the regular pump might be stopping pumping as the valve in the pump is closed under pressure. (that is all conjecture as it has been along time since I worked on a flathead pump. So it may just be my old mind has gone away.
My brother just bought a 1970 ElectraGlide, takes it out, it stops running. Pops gas cap to have a look, plenty of gas. Starts back up, rides a mile, it dies. Pops the cap again, same thing. We are thinking the tanks have some crap in it, so start to pull them. The. P.O. Removed the "T" between tanks, one of which was a vent, and replaced with just hose and no "T". We put one back in along with a length of hose for the vent. Never does it again. Check the cap.
Will the thing start and run after sitting for a while, then repeat the cycle?? If so, that is a classic description of a dying coil or condenser. Either will drop output as it heats up, work perfectly well when cold.
Not sure which dist. you're using, but if you haven't replaced the condenser, try that. These innocent looking little devils have caused many-a headaches !!!
Almost all of the condensers that are available are made in China. I've gone thru a few of them in the last couple of years.
Hope you have tried this. I'm thinking vapor lock also. No fuel in carb will answer that question. Then it's either fuel line heat or pump not pulling fuel thru electric pump. I bought a simple spark tester that goes on plug and fits in wire. Super easy to check spark.
How bout the carb spacer..maybe fuel is boiling? Or my guess condenser Posted using the Full Custom H.A.M.B. App!
Cut your possible issues in half by duct taping a timing light to the windshield so you can see it flashing as your driving, if the motor stops running and the light stops flashing its spark, if you roll to the shoulder with the motor still turning(clutch out still in gear) but not running its fuel.......and what a lot of guys said...if its spark look at condenser and coil......just cause its "new" doesn't mean it's good!..... Posted using the Full Custom H.A.M.B. App!
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