Stalling while driving

[hgraham]

For those who haven't followed my recent posts, I had some trouble with vapor lock in warm weather and installed a Facet electronic fuel pump. On my test drive to check the pump, one of my coils went out and I ended up replacing both coils with new Bosch blue units (with the internal ballast resistor). On the new coil test drive, the car started and idled better than ever and made it about 5 minutes around the neighborhood before the engine sputtered and quit. After a minute, it would start again and run as if nothing happened, drive for a block, and quit again. I eventually made it back home (a block at a time) and the car idled perfectly in my driveway for 15 minutes or so while I poked around to see if I could find anything wrong. To me this sounds like fuel starvation, and I suppose there is the possibility that the pump needs to be mounted vertically as Tom suggested, but I wanted to see if anyone had any other ideas for possible causes.

Hudson

[tyang]

Hi Hudson,

The easiest way to check is when the car stalls, pull the top of the air cleaner off, and operate the throttle linkage. If there is no spray from the accelerator pumps down the throats of the carbs, the fuel bowls are empty. To see if the electric pump is working properly, take the hose off the fuel rail and pump some fuel with the electric pump into a container. It definitely sounds like the fuel flow is not keeping up.

Tom

[John Vardanian]

The other thing, if your car has a glass filter bowl, look at that and if it's not full then that's another indication of fuel starvation.

john

[Al Pezzella]

I too have had many problems with being let down on the road. Have had vapor lock and I did install facet pump which took care of the fuel problem. But I see that you burned out one of your coils and I burned out about 5 sets of electronic ignition modules. I have my car at Toms now to switch back to points because it has been impossible to pin down the reason why the modules are burning out even though I know that it could only be from either low voltage or high voltage. Unfortunately I don't have a recording meter in line to see exactly what is happening. I've change alternators, regulators and I've exhausted all other possibilities but at one point I did find that at the fuse terminal the connection was intermittent so I fixed that. Well the short story became long.
What I'm getting at is if you have fuel, check electrical.
Oh by the way after Installing facet pump, I still had fuel problem until I cleaned out check valves in mechanical fuel pump being that facet feeds through mechanical.

[hgraham]

Thank you all for the great advice. When the car stalled the first time, I thankfully had the presence of mind to take off the air filter housing cover and look into the carbs. The rear most carb was dry, but when I pushed the throttle lever, fuel squirted into it and quickly evaporated so I think it was just engine heat making it look dry initially. I haven't taken off the hose at the fuel rail to check flow. I know that fuel is flowing, but I think I would need to use a gauge to determine if enough fuel was getting there unless there is a shadetree mechanic's method. I would assume that if fuel is flowing adequately at the rail that I wouldn't have problems with my mechanical pump check valves, correct? If there's bad flow, I'll definitely check out the mechanical pump. I did check the glass filter bowl and it was full at every stall.

Al, I'm glad to hear things are getting sorted out with your car. After reading Tom's articles, I'm definitely steering clear of electronic ignition. My switch to Bosch coils was more a matter of cost and reliability, but they supposedly have comparable specs to the Marellis and shouldn't burn out my points. Then again, maybe I should go find some wood to knock on!

[hgraham]

It did turn out to be a fuel problem caused by a kink in the new fuel hose after installing the Facet pump. I posted the rest of the story to that thread for anyone who is considering doing that conversion. Thanks to everyone here for your help!

Hudson

[Steve Meltzer]

Yes, the Facet pump should be mounted vertically. Just did it on my GTC. I can email you the drawing Dyke did for me, showing where to mount a fuel pressure gauge to check out the system. Webers like about 4PSI and vapor lock is common without the electric pump running. s