Vapor lock or something like it

[SevenT]

EFI Gurus,

I have an EFI converted '70 Bronco and the weather has gotten much warmer here in CO and the stalling issue is back.

Vehicle particulars: 1988 Lincoln Town Car engine converted to Mass Air, metal fuel lines (supply from tank up passenger side of frame, return down driver side of frame), 65 PSI fuel pump on frame just in front of 23 gallon tank, EEC in glove box.

Symptoms are heat related I am certain. With outside temperature in excess of 75 and operating temp of engine 195 - 200, it will stall and be hard to restart.

I have relocated the TFI module to the fender on a heat sink out of an E-350 van, wrapped supply line to insulate from engine heat. Used Reflectix double reflective insulation (from Lowe's) along the heater box and firewall to cut down on heat transfer. The fuel pump is directly above where the current muffler is located.

Any ideas as to what I am missing? Do I need to move the fuel pump?

TIA,

SevenT

 

[RV77]

Just throwing this out there but Could your fuel pump be the culprit.I have read/heard that you want the fuel pump IN the tank to keep it cool and not "pull" the fuel from the tank rather have it "push" the fuel.

 

[Viperwolf1]

My instinct says the pump isn't pulling enough fuel when hot. A fuel pressure gauge would confirm that. Could be the pump is just getting old or filters may be getting plugged. The best place for a pump is as close to the tank as possible and as low as possible so gravity assists it.

If the TFI is the problem you won't have spark. That's easy to check.

 

[TRSmith99]

For what's its worth....

My wife has a 1977 Fiat Spider and we were having very similar symptoms (we're in Oregon). When the car was "cold" everything ran fine. When the car warmed up, it would sputter and stall. Eventually, we realized the problem was "worse" when we were driving up hill - still thinking it was a vapor lock or something.

I was chatting with my local mechanic. He suggested a marine gas additive to get water out. He further explaned that ethanol gases can attract more moisture and condensation. In the spring (at least in Oregon) our gas was higher than the E10 mix.

All I can say, it 1/2 can of the marine gas additive ($5) = problem solved.

 

[70_Steve]

I would check the fuel pressure when the engine is hot and hard to start.

 

[Recko555]

I have had similar issues out in Moab. I have an in tank pump also.
Watching this thread closely.