Engine dies out

[70_Steve]

I thought about this some more. Maybe my question should be different. When I do get her good and hot, and am successful in getting her started, it's always a really fumbly start, never a good solid start. It's usually a fairly long crank, then a bumbly fire, and eventually smooths out to a nice running engine. So...

What would cause a really weak start when she's warm?

Could be a sensor failure, and/or running in "limp" mode.

Might want to keep stuff with you to at least run KOEO codes when the engine won't start.

 

[HGM]

Might have missed it, but have you tried a coil? I've seen those E-core coils do funny stuff like that in the past..

 

[collinbrewer]

I'll try running the KOEO next time she won't start.

I thought it might be a coil, so I replaced that a couple weeks ago to no avail.

 

[sstclair]

I looked through this thread again and didn't see where you positively ruled out he Fuel Pump. Like others posted. I too, had this exact situation and mine was the pump. It'd randomly quit for about 10 minutes, sometimes cold, sometimes hot. Sometimes after 5 minutes of run time, sometimes hours or days. Mine was a low pressure feeding a high pressure. When we finally diagnosed it you could hear the pump spinning but way too slowly. It never threw codes btw and I replaced everything from the ECU, any critical sensor, and all the relays in the process.

-Steve

 

[brianstrange]

Two items that many overlook in a vintage EFI swap, are 1) using the resistance wire to power your ignition circuit,and 2) using a solid state voltage regulator if using the original alternator. Those two items can cause issues. Check the actual voltage at the run wire, and make sure you're getting close to 12 Volts, and make sure you have a small style voltage regulator.