I have a 1995 ranger xlt with the 3.0 5 speed. When cold it will fire right up and idle just fine for 10-15 minutes and then will shut off unless i idle it above 2000 rpm. I have replaced the pcm, ignition coil, spark plugs, wires, fuel pump, fuel filter, clutch, all to no avail. Only shows just over 200 rpm when cranking trying to restart. Have to wait a good hour or more for it to cool all the way down before it will restart. No fuel coming from fpr when vaccum line is removed. Engine idles down when maf is unplugged. I can hear the fuel pump prime after it shuts off. Ive tried everyi can think of or find. Please help.

 

Welcome to the forum

Yes, that sounds like a real puzzler

200rpms is the correct cranking speed for most gasoline engines, just FYI

When you turn on the key the CEL(check engine light) should come on, that means computer has booted up
Watch the CEL and crank the engine, it should go OFF as soon as engine starts to turn, that means computer is getting the timing signal from Crank sensor
No timing signal means no start
There is no connection between starter motor and computer, the computer has no idea you want to start the engine UNTIL it sees that timing signal and then it starts spark first and then injectors one second later

If CEL is not going off when cranking then either Crank Sensor or its wires to computer are the issue


Try the 50/50 test to see if its a spark or fuel issue
After engine is warmed up and will not restart, and CEL goes off when cranking
Pull off the air plenum(tube) on the upper intake manifold
Open throttle and spray gasoline or quick start(ether) into the engine
You can leave plenum off for the test as long as fan won't hit it

Try to start engine
If it starts and dies then fuel delivery is the issue
If it does not start/fire then its a spark issue

Having fuel pump running and fuel pressure doesn't mean injectors are opening
50/50 test has been around since late 1890's when gasoline engines were first being used still the best test to do for crank but no start issues, lol

 

I did the wide open throttle crank that ive seen mentioned in a few threads after it shut itself off...it did start but ran rough. So that pretty much narrows it down to a fuel injector that is slightly stuck open...unless im reading it wrong

 

You said you have to wait for an hour for it to restart????
But now it will restart after shutting down when warm???
If it was a leaking injector you would also get a BIG bellow of smoke out the tail pipe on restart, do you see that?

 

When its warm i push the throttle to the floor and crank it and it starts. When cold i start it like normal. Yes on restart there is alot of black smoke.

 

Then yes, I would first check Fuel Pressure Regulators vacuum hose for gasoline, if found replace regulator
If Vacuum hose is dry then you can replace all the injectors OR you can test for which one is leaking

Cold engine
Unplug 4 wire connector on coil pack
Cycle key on and off 4 times
Press gas pedal down to the floor and hold it down, as you already know this turns off injectors
Crank engine over 3 times turning key off and on between cranks
Now pull out the spark plugs
WET tip will indicate leaking injector

This is good to do even if you plan to replace all 6 injectors
The injectors all get 12v with key on, the computer grounds each injector to open it
IF(big if) one of the injector wires back to computer has a bare spot or ?? it could be grounding out, so injector opens, so not a "leak" but same as
If you know which one then...............can give that a better/closer look

 

Would a higher fuel pressure from the pump cause them to leak? When i replaced the fuel pump i went with one that had a higher psi so IF i decided to upgrade parts later i had the fuel pressure to deal with the upgrade

 

No, the factory pump was capable of 80psi and system only runs at 35psi
Higher flow pump wouldn't matter, just more fuel flows back to the tank on the return line

Same injectors are used with 35psi or in later years(1998 and up) with 65psi
Injectors are also forward flow blocking, meaning the valve needs to be pulled back to let fuel flow in to engine, there is a spring that holds valve down but so does the pressure behind the valve, so higher pressure holds valve closed tigher, vs pushing it open