engine runs very rough and then shuts off when warm

[singleton8068]

93 ford ranger 4wd
4.0 v6 with approx 9k on the motor
5 speed jasper transmission

my engine runs great when its cold but as soon as it warms up the engine runs very rough. the truck shakes violently and then shuts off. it takes multiple starts to get it going again but will continue to do the same thing weather im driving or not. when it starts to shake i lose all acceleration and it just stops. i did plugs, wires, and a coilpack. i ran a bottle of stp injector cleaner and just replaced the fuel filter thinking it was the problem but it continues to do it. ive run outta things to try.

 

[shane96ranger]

93 ford ranger 4wd
4.0 v6 with approx 9k on the motor
5 speed jasper transmission

my engine runs great when its cold but as soon as it warms up the engine runs very rough. the truck shakes violently and then shuts off. it takes multiple starts to get it going again but will continue to do the same thing weather im driving or not. when it starts to shake i lose all acceleration and it just stops. i did plugs, wires, and a coilpack. i ran a bottle of stp injector cleaner and just replaced the fuel filter thinking it was the problem but it continues to do it. ive run outta things to try.

Have you checked for fuel pressure when it dies? Just wondering if your fuel pump is the issue?

 

[singleton8068]

i just pulled the whole intake off, the throttle body, and the mass air flow sensor and cleaned them all with the appropriate aresol cleaners and it didnt change anything.

 

[singleton8068]

i had the fuel pump replaced about a month ago right after i got back from deployment.

 

[getjackedup]

when you swapped for a new fuel pump did you check/swap your fuel pressure regulator?

 

[feellnfroggy]

GO to the junkyard and get a new used MAF. These go out alot. You can clean them all day long but they just dont work. The engine runs fine colds because its open loop (running rich) But when it warms up closed loop the MAF gets no readin and it shows running lean, so the computer compensates and runs it rich, but its enough to wet the spark and it dies. A way to test this is turn the truck on without the MAF plugged in. If the MAF really is bad it will run better without it. Let us know.

 

[singleton8068]

ive been trying to get it started to try the maf sensor but its not starting. the engine turns over but it seems as if its not getting any fuel. its getting cold outside so im gonna try again tomorrow morning.

 

[singleton8068]

i tried starting it but it wont start. the engine turns over but it wont fire. im gonna replace the fuel lines and see if that doesnt fix it. if not atleast ill have new fuel lines.

 

[singleton8068]

the fuel lines were good. i got it started and it was running like shit. i unpluggeed the mass air flow sensor and it ran better then with it. it was still running like shit but a lot better. im on my way to buy a new sensor.

 

[singleton8068]

problem fixed

i bought a new mass air flow sensor and its running better then it ever has.

thanks everyone

 

[feellnfroggy]

Glad to hear it.