Anybody know about non-intercooled fords?

[Idaho CTD]

A friend of mine is getting some sputtering/stumbling at low-mid rpms. He said it only does it when it is hot out. It doesn't do it when it is up to running speed. He is a mechanic by trade and this is stumping him so any help would be appreciated.



Nathan

 

[FFutch]

My .02...

More than likely the fuel pump is going south. Is it a 6. 9 or 7. 3?I think though the fuel pump is basically the same. It is an I. D. I. ,right?If it's a Power-stroke than possibly a cam position sensor... . Doug

 

[Idaho CTD]

Doug,

His truck is a pre-PowerStroke 7. 3l. It is non-intercooled so I'm guessing it is a '93-94 (he didn't tell me). I dont know what a I. D. I. is so I cant answer that. I'll ask him if he checked the F. P.



Thanks

Nathan

 

[FFutch]

InDirect Injection...

... which is what he's got. They had pre-combustion chambers in the heads to pre-heat the fuel. Not a very efficient way to burn fuel but it works. The power-strokes went to direct injection like the Cummins had all along,which means they squirt the fuel directly on top of the piston. So now you know. I'm by no means an expert on the I. D. I. s but we had a panel van that was doing similar to what you're describing. We tweaked the timing a little by loosening the pump mounting bolts and moving it slightly. Ended up replacing the pump. I'm talking injection pump here. It's on the front of the engine in the valley with 8 lines coming out of it. Maybe some of these other guys will chime in,or you could also try Ford Diesel.com. How many miles?It seems I read about the inj. pumps needing work at about 100k... . Doug

 

[Evan A. Beck]

WAIT!!!

Before condemning the injection pump, be sure to do a compression test. I have seen many of these with a miss like you describe, and it has turned out to be low compression on a couple cylinders. If compression is ok (they should all be around 400 psi), then check your fuel pressure. Should be around 4-5 psi at idle, and no lower than 3 psi under full load.



If the above checks out ok, then its time to replace the injection pump and injectors. Always replace injectors at the same time you do the pump, along with the fuel return lines between the injectors. Be sure to buy NEW injectors--NOT remanufactured. A reman injection pump is ok though.



Typically, the injection pump on the 6. 9L/7. 3L IDI diesels usually lasts about 100K, give or take 20K. The good news is they are pretty cheap, same goes for the injectors.



I've worked on dozens of these things, so feel free to PM me with any questions!

 

[Idaho CTD]

Thanks Evan

I didn't talk to him today but I will try to call him tomorrow and tell him what you said. If he has any more ?'s then I'll PM you.



Thanks Again

Nathan