Everything was going so good
My 71 340 Duster . I went to a car show after sitting there all day car fired up and I drove to an Ice cream stand up the street close to home I sat there for about 20 minutes and the sub started going down. I went to start it and it would not start .
What I notice is the fuel pump was not changing sound like it always does when pressure was up. I shut the pump off and took the air cleaner off it was flooding. So I left the pump off and held it flat to the floor and it started but when I turned the pump on it died. So I kept turning the pump on and off and after a couple times it stayed running. I felt like a fool in front of all the other people there with cars.
This puzzled me it never did this before. But On the way home from the show I stopped and top the tank off with pump gas before going to the ice cream stand.
After some research and talking to others we determined the ethanol / oxygenated fuel was boiling in the line and carb. This caused the needle and seat not to close due to the floats not being lifted and the constant dead ending pressure on them
I installed a return line in the car using return regulator. This allowed the fuel to circulate. The car never did this again. I found out in the late 80's mopar install a return system on all there cars for this reason. Now every car I build gets a return filter if it has a mechanical pump. Electric pump cars get a return regulator.
The picture below of the orange car you can see I added the return line . on the other engine with the mechanical pump was for a car I just finished. It works perfect just went to the same show and stopped at the same ice cream stand.
I believe this is your problem if you don't find it to be spark related. My car never did it after it started and restarted unless I drove it and went to start it after it sat for only 15 minutes. Once it cooled down there was not a problem or if I restarted it soon after it was shut off..
Before the return on the Electric pump car
After the return regulator was installed
This is the return filter used on the mech. fuel pump cars by the factory in the 80's due to this problem with the fuel boiling
My 71 340 Duster . I went to a car show after sitting there all day car fired up and I drove to an Ice cream stand up the street close to home I sat there for about 20 minutes and the sub started going down. I went to start it and it would not start .
What I notice is the fuel pump was not changing sound like it always does when pressure was up. I shut the pump off and took the air cleaner off it was flooding. So I left the pump off and held it flat to the floor and it started but when I turned the pump on it died. So I kept turning the pump on and off and after a couple times it stayed running. I felt like a fool in front of all the other people there with cars.
This puzzled me it never did this before. But On the way home from the show I stopped and top the tank off with pump gas before going to the ice cream stand.
After some research and talking to others we determined the ethanol / oxygenated fuel was boiling in the line and carb. This caused the needle and seat not to close due to the floats not being lifted and the constant dead ending pressure on them
I installed a return line in the car using return regulator. This allowed the fuel to circulate. The car never did this again. I found out in the late 80's mopar install a return system on all there cars for this reason. Now every car I build gets a return filter if it has a mechanical pump. Electric pump cars get a return regulator.
The picture below of the orange car you can see I added the return line . on the other engine with the mechanical pump was for a car I just finished. It works perfect just went to the same show and stopped at the same ice cream stand.
I believe this is your problem if you don't find it to be spark related. My car never did it after it started and restarted unless I drove it and went to start it after it sat for only 15 minutes. Once it cooled down there was not a problem or if I restarted it soon after it was shut off..
Before the return on the Electric pump car
After the return regulator was installed
This is the return filter used on the mech. fuel pump cars by the factory in the 80's due to this problem with the fuel boiling