Engine/Transmission (1994 - 1998) '95 INJECTION TROUBLES Help

[Motorhead]

I have a '95 auto that is having some serious running problems. Maybe someone out there in Diesel Land can give me some ideas.

The truck has only 95,000 miles and has been well cared for. It started missing and lost power and would stall. I changed the fuel filter and cut open the old filter finding very little crud in it. It also flowed ok. I checked the lift pump and it puts out good. I removed the pressure relief valve and blew it out and checked the spring. It was ok. I bleed out the system and it started and ran ok. I took it out and drove it aggressively and then got on the freeway. I ran it wide open for a while to ck that the lift pump was supplying enough fuel. AS I BACKED OUT of it at 70 mph, it started missing and the throttle pedel felt hard. It ran crappy and was actually missing on and off on a few cylinders. I checked the exaust while it was running bad and it is NOT smoking excessively. If you can get it to idle, it hunts.

This poor running starts in an instant.



What do you think. I am thinking that the inj pump has a problem.



ANY IDEAS OR SOMEONE EXPERIENCED THIS??? Chris

 

[DRAG DIESEL]

have you checked out your overflow valve?

 

[mikel]

My '95 did this exact thing once after 'playing' with some guy in a powerstroke.



I was full throttle at better than 3000 rpm for a little while and then when I backed out of it the engine missed and died if I pushed the clutch in. I had to coast almost a mile with it in gear before it started to pick back up, and as it began to come back to life it would run if you didn't push it too much, but if you tried to give it too much throttle it would miss out and want to die. My throttle was hard too, just like you describe.



I called Piers Diesel and talked to them (I can't remember who, though) about it and was told that sometimes a vacuum can be created somewhere within the injection system and the truck will pretty much 'run out of fuel' even though the lift pump is not bad and there is fuel in the tank. I got the impression it was kind of like vapor lock on a gasser. It probably didn't help that I had less than 1/4 tank of fuel though.



They also said that this is more common on the 24-valve trucks.



I haven't done anything to the truck to try and "fix" this and it hasn't happened again, but I also haven't run it as hard since then either so I don't know if it was a "fluke" or if it's just waiting for the next time I want to play with a ford to act up again.



Good luck, and if you figure out what caused it let me know.



Mike

 

[Motorhead]

The overflow valve is ok. I removed it and blew it out and ck'd the spring and ball seat.

 

[bmoeller]

Originally posted by Motorhead

The overflow valve is ok. I removed it and blew it out and ck'd the spring and ball seat.

Did you check the spring legnth? Supposed to be . 5" I believe.

 

[Deezul1]

Over flow spring is supposed to be . 500 long. Stretch to . 550 and reinstall to see if there is a diffrence, if so get a new valve some day. I had one that was bad, stretched it and ran it for over a year and then sold the truck still running good. Also return line being bad can cause all sorts of weird problems.

 

[Motorhead]

I'll ck it... . I have an appointment with a pump shop on thursday. Thanks.

 

[Joseph Donnelly]

Check fuel pressure at idle and 2500 rpm. Overflow valve or lift pump could be weak. If not you may need inj pump work.

 

[Motorhead]

Joe, can you give me the pressure specs? Thanks Chris

 

[bmoeller]

Fuel Pressure: 18-24 psi at idle, 28-36 at 2000 rpm with no load.



http://dodgeram.org/tech/dsl/Facts/94specs.html

 

[Motorhead]

Thanks, I'll ck it

 

[Motorhead]

THANKS.... THANKS.... THANKS!!!

THANKS TO ALL OF YOU "12 VALVE HEADS" THAT HELPED ME OUT WITH THE RUNNING PROBLEM ON MY BUDDIES '95. .

I took out the return relief valve again and took it apart and measured the free length of the spring. It was only . 450" and apparently the problem. I stretched it out to . 520 and put it back together. I put 25 miles on it with a lot of W. O. T. and it didn't miss a beat!!! I told my friend to try it out for awhile and if all is well, we will replace the relief valve with a new one. SURE is a hell of alot cheaper than someone telling us that the Inj. pump was shot!!!

Well as that problem was fixed and sent down the road, a guy that I work on his '77 300D MBZ called me and said it wouldn't start or run very well. I went to his house, pumped the lift pump and started to bleed the filter out and smelled GASOLINE!!! He had accidentially filled his tank FULL with gas. So here comes another job my way!



AGAIN THANKS!!! I can and HAVE counted on ALL of you guys for GOOD, ACCURATE Information. Peace, Chris

 

[bmoeller]

For a new overflow valve, as far as I know, Piers has them for the best price. Almost half what I paid for mine at Cummins.

 

[Motorhead]

bmoeller, Thanks for yet another "TDR Member" tip. I am going to let him drive it for a month or so to make sure that it was the problem. If it WAS the culprit, I suggested that we replace it.

THANKS for all of your help!!! CHris