engine studder and dying.

[hvac]

Hi guys,
I have a friend that has a 1988 ford ranger with 300,000k and it has been running good .
Then this year the engine started having problems cutting out or studdering and sometime the engine will cut off in while driving.
He has had the car tuned up with new plugs,wires,cap, and rotor button and the truck ran good for a couple of days and then started it again.

I asked him if he had changed the fuel filter and how long it had been since he ran some fuel injector cleaner through his system and he had changed the fuel filter recently, however had not ran any cleaner through the system.
do any of you experts know what may be causing his problem or have any advise on what to try.
I would appreciate any and all suggestions or comments.

 

[RussellA]

If it's cutting off completely I don't know if that can be clogged injectors. What's the odds of them all stopping up at the same time. I would look at fuel filter again. It's not how long since replace, but has it been replaced since last bad gas. Might want to change gas stations, could be they have junk in their tanks. Also I have seen a bad fuel pump relay do this.

 

[Mike242GT]

hvac:

Not familiar with your friend's make or model, but most fuel injected vehicles have some sort of sensor which sends an RPM signal to the engine computer, telling it that the engine is running. This can be a Hall-type sensor on the distributor, or a flywheel sensor on the bellhousing. Without this signal, the fuel pump will not run. There may also be a relay in the circuit to the fuel pump which is going bad.

 

[moribundman]

Not sure about a Ford, but on an Audi those symtoms might point at a dirty/defective MAF sensor. If the Ford has a MAF, I'd definitely check that out.

 

[Drew99GT]

Basic diagnosis: check fuel pressure; igntion componets such as ignitor/coil. Check all those with a multimeter. Then go for vacuum diagnosis, which is a bit difficult if the engine won't even run

With that high a mielge, you can't rule out the possibility of perhaps a timing chain slipping a tooth? Seen that happen before and watched a friend replace EVERYTHING in his engine he could only for me to unbolt the front cover and point out to him that timing marks were off by on tooth.