2001 Ford Excursion 7.3 will run barely for about 20 sec. shudders, then dies. Bought new, driven 334K miles. Performed the usual fixes common to 7.3’ issues over the years. All original injectors except for #7 which I replaced about 5 yrs ago. (I know should have replaced in sets but not in the budget at the time). Anyway had my wife turn the engine over after I had removed valve covers for inspection and observed a lot of smoke coming out of what appears to be at or around number 7 rocker arm valley? All rocker arm/pushrods look to be moving as they should beyond that I'm in over my head. Am I screwed or could it possibly just be a bad injector/injectors? Thanks, charlie

 

How is the wiring harness connection at valve cover ?

 

I replaced both about 2 yrs ago. This time around I removed the IDM and ohm'ed out all the pins on the cable plug and all tested at what they should. But thanks for the good idea.

 

How much fuel is in the tank? Do you have any way to monitor any of the PCM/sensors?

 

It's got about 3/4's of a tank. I added 10 more gallons since the no start just to make sure. I dropped the tank and replaced the broke off fuel pick up screen and clogged fuel return lines in the tank about 6 months ago because it would die with a 1/4 tank. The screens were full of I guess "varnish" off the plastic tank, I got educated about that on this forum and it being another common issue with my truck. I also resolved it with instructions from this site. But thanks for the idea. I think I found the issue though, I pulled out #7 injector which I replaced with a rebuilt one from Swamps about 5 yrs ago. I then pulled out the next one same side where the smoke is coming from. The o-ring and seals are shot. There is soot/carbon way up the injector so I'm guessing the combustion gasses/smoke? are leaking through and that's what I'm seeing. So I'm guessing the other original 6 injectors are not much better. They do still buzz but I guess that just means the solenoid is working but not necessarily all the injector components. I'm struggling here trying to explain it correctly, hope it makes sense LOL but thanks again anyway.

 

It makes sense. Can you get a picture of that injector and the o-rings? You MAY not need new injectors, it may just be a situation where you need to put new o-rings on them. If they were failing, you won't have enough ICP for the truck to start. Riff Raff sells them for cheaper than my local dealer told me they pay for them.


Alliant Injector O-rings - Ford 7.3L Powerstroke (94-03)

 

Sorry about the late reply. I'm out of state until Mon but will take pictures when I get back and post. I'll be interested to get your opinion when when you view them, thanks.

Alliant Injector O-rings - Ford 7.3L Powerstroke (94-03)[/QUOTE]

 

Hi Hkusp, here are 3 pictures of the injectors. The one on the left I replaced at about 250K, the other 3 are original with 336K miles. let me know what ya think, it sure does look like catastrophic o-ring failure. Any idea why the injector tip on the newer injector on the left would be black unlike the others? Glow plugs all looked good, forgot to include them in pic.

 

What is weird is the truck uses no oil, shouldn't it have high oil consumption with these bad o-rings or am I getting things confused?

 

About $10/injector or less for genuine Alliant oring sets. Good time to spend it.

These machines hold 15 quarts of oil. Might not notice a quart or so

Looks like you've found your problem! Don't forget the copper washer and make sure it doesn't fall loose when reinstalling.

Others can give better tips with more experience, but I can tell you that you are likely to notice a significant difference in the way she runs

 

Ok thanks, I'm going to price having them rebuilt as after a little research there are several internal o-rings and wear parts as well. If I didn't have so many miles on these, I agree with you doing just the external oring kit would probably get me back on the road but I don't want to be tearing into this another yr. from now. Their are several rebuild kits out there and I watched a few videos of the rebuild process. But too many little parts for me which have to be replaced in the correct order. I just want piece of mind because I don't do this sort of work to be good at it. In other words I'm afraid I would screw it up. LOL. I really appreciate the help, thanks

 

Looking back, it seems you have 334k on the original injectors? If so, no shame in rebuild/replace for sure!

 

I am not sure why the tip would turn color on one versus another. I remember a few of mine were that way as well. Call Tim or one of his guys at P.I.S., or Ryan Casserly at Full Force Diesel. They will talk with you and get you pointed in the right direction.