Engine dies at high RPM and won't start

[speeence]

We have twin Ford 302's recently rebuilt. The problem we are having is after running the engines at approx 3000 Rpms for about 20 minutes, the starboard engine dies and will not restart. Once the engine has had a chance to cool, (after about an hour), it will restart on the first crank. The temp on the engine seems OK before it dies, never getting over 160 degrees. Where do we start trying to diagnose the problem. Our gut tells us its electical, but we could be wrong. Any advice would be appreciated.

 

[Bondo]

Re: Engine dies at high RPM and won't start

Where do we start trying to diagnose the problem. Our gut tells us its electical, but we could be wrong.

Ayuh,.... When it Quits,....Is the time,+ place to See what's missing,....

Fuel, or Fire,..??
Then work thru whichever one's missing's flow chart....
Fuel at the Carb,..??
Power to the Coil,..?? From the Coil,..??

 

[dontask]

Re: Engine dies at high RPM and won't start

Just a couple suggestions since you have spare known good parts (on the engine that does not shut down). It could be electrical or fuel. Does it have spark after it dies? If you lost spark you could try swapping the coils over and try again. The coils heat up with use and there is a point at which the insulation could be breaking down. Next try swapping the condenser over. If it is not electrical try fuel supply. Possibly the fuel filter. I used to do fleet maintenance and I had to deal with angry employee that was putting small soap bars into the gas tanks and the units would run until the soap particles built at the filter (gasoline will not completely dissolve all hand soap types) . At that point it shut down, wait for soap particles to settle down in the filter bowl and the engine would start again and run for a while. After looking into one of the fuel tanks I found the soap bar (bars). Not saying soap in your case but debris could be surrounding the filter enough to choke the fuel supply off. Another issue like yours was another mechanic working on a boat fuel tank used regular engine silicone to seal a tank level sending unit back onto the fuel tank at top (instead of installing a new gasket). Well regular silicone does not do well getting washed by fuel sloshing around. The sealant turned into a snot like goo and dripped to the bottom of the fuel tank. The fuel would not completely dissolve the silicone and it would start to travel up the fuel tank pick up tube and then shut the engine down. Let it sit for a while and the silicone snot goo would settle down the tube and the engine would run for a while. At idle it would run all day, but raise the engine rpm's and it would shut down shortly. Your problem should be easy to pin down cause you have known good parts on your other running engine available at no cost. Good luck

 

[speeence]

Re: Engine dies at high RPM and won't start

Thanks for all the input. We have checked the carb, and it appears that fuel is not the culprit. After doing a little more digging we think we may have found the problem. The coolant reservoir is close to the distributor cap, and the drainage line coming off the top of the reservoir had come loose. We had just filled the reservoir and it appears overflow coollant was squirting on the distributer cap. We pulled the distributor cap and found some moisture so we think thats probably the issue. Thanks again for all the input.

 

[180shabah]

Re: Engine dies at high RPM and won't start

...that might do it.

 

[Bondo]

Re: Engine dies at high RPM and won't start

The coolant reservoir is close to the distributor cap, and the drainage line coming off the top of the reservoir had come loose. We had just filled the reservoir and it appears overflow coollant was squirting on the distributer cap. We pulled the distributor cap and found some moisture so we think thats probably the issue.

Ayuh,.... Those darn Fords,... They put the Distributer on the Wrong end of the motor.....