So, do 914’s get vapor lock? It was a 70+ degree day here in Portland, and I was out for an extended ride in the foothills SE of Portland. I stopped in a Supermarket parking lot for 5 minutes, and the engine was dead.

I has 1/4 tank of gas, good spark from coil & spark plug wire, battery & starter were turning strong. After waiting for 45 minutes with the engine lid open it still wouldn’t start. At this point my road service guy showed up. After a tow
truck ride home, watching St. Helens blow on the way, It started right up as the tow truck drove away. Is this classic vapor lock? Runs great now. Do fuel injected systems fail when the engine bay warms up?

Yes, 914s vaporlock, but not usually at 70 degrees. My 73 vapor locked on 90+ degree days till I moved the fuel pump to the front trunk. After that it never happened again. The original location of early cars had hot air dumped directly on it from the closed flapper valve. Next time it happens, pour some water on the fuel pump. If it starts, you have your answer. If not, the fuel pump or CHT could be at fault

Curt: I was about to inspect the fuel pump when my road service guy showed. The fuel pump on my ‘75 is located in the front trunk, which is why I thought I was immune to vapor lock. What is the CHT?

Cylinder head temp sensor. Hmmm, I had the exact problem with my 75. It would just die for no reason. Turned out to be the air filter.

Hmmm, my air filter is a almost new NAPA paper filter. Do KN filters make a huge positive impact? perhaps if this happens again i'll pop the filter compartment open.

Could be a relay board problem. Mine was having fuel pump troubles and I traced it to the relay board. wiggling things would make the fuel pump work/not work.

It might be the planets or Mt. St. Helens, but I have had the same problem the last couple of days here in Portland as well. Ran a thread the last couple of days, consenses is the CHT. I'm out of town the next couple of weeks, so you will get a chance to try the advice before I do. Please PM me and let me know how it goes for you.

Gary

Gary, three of us are having the problem right now. I just ordered an new CHT and will get it installed and let you know if that solves the issues. I also plan to give all the wiring a good look over/cleaning at the same time.

Travel safe.

I'm going to check my fuel pump circuits, fuses, and relay to see if anything is loose.

Side note, I had a new car audio deck installed yesterday. I truly doubt this had anything to do with the engine not starting for 1.5 hours and then starting again like there never was an issue, but until I solve this problem, it is suspect as well.