2.3L ('83-'97) Intermittent start/die when warm

[Lil'Red1997]

I have a 97 2.3 manual 2wd. It does not have any codes and runs fairly well. I've averaged about 20mpg in the 3000 miles I've had the truck which I understand is fairly low. I've read rangers aren't quick but this think makes my prius seem zippy. I can live with poor mileage and acceleration as it's just a play thing but I don't wanna get left stranded.

It starts and runs just fine when it's cold aka my commute to and from work. Sometimes, but not all the time, the truck will refuse to run after a brief stop. It will start, run for 2-3 seconds and die. Cycle key on and off run 2-3 seconds and die. For instance I've shut it off to run into a coffee shop to pick up my order from the to-go shelf and the truck will not run. To be clear, it will have been sitting for less than two minutes and not start. After a few cycles of key on-off stumble/die it will start and run no problem. I have also had this issue after killing it at a stop sign, stopping to get gas, and even shopping for about 20 minutes (the wife was with me and it started first try after she got out of the truck to listen for the fuel pump).

I have jumpered out the inertia switch and changed the fuel filter. Holding the gas pedal to the floor while cranking doesn't seem to make a difference (won't fire at all) and neither does pumping the pedal before/during/after cranking. When it is running for those few seconds pumping the throttle kills it immediately. Cycling the key on and off to prime the fuel pump doesn't seem to make a difference either. I have replaced the relay with a "known good" relay a friend gave me from a chevy that was in a junkyard. It has not died while running.

Any ideas?

 

[dvdswan]

How much fuel do you have in the tank when this happens?

 

[Lil'Red1997]

This has happened at all tank levels.

 

[Masonbrant]

Mines got a very similar issue next time it stalls out try unplugging the maf if anything like mine it will idle fine and not like taking off from a light but will run good enough to get you home. I've put 2 brand new mafs on my truck and only get a month or so out of them so I think I've got bigger issues. But try unplugging the maf if it helps maf is probably bad.

 

[Shran]

Sounds to me like you have a plugged up fuel filter or your pump is weak. I would try the filter first regardless, see if there's an improvement and if not, get a fuel pressure reading and go from there.

Holding the pedal to the floor while cranking the engine disables the fuel injectors, that's normal.

20mpg sounds about right. Mine have always been right around that area in warm weather. And they are definitely not fast trucks!

 

[Lil'Red1997]

The fuel filter has been replaced within the last thousand miles and I tested the fuel pressure with a harbor freight fuel pressure gauge, see below. The truck did seem to run better after replacing the fuel filter but I still have the starting issues.

Key on engine off 35 psi
Idle steady 30psi
Rev the engine it jumps to 40psi
Holding higher rpm steady 30psi
Left the gauge on at 12:30pm with 35psi and checked it again at 8pm and had 20psi.