EDIT: Not stranded anymore, just confused at this point!


Hello everyone! New to the forum here, and really need some help. I've been hunting and hunting but it seems some have a problem like mine at all times where mine is intermittent. I just returned from vacation when this occurred and will try to give a "timeline" as to what happened.

First off, I have a 1995 F250 SCLB 4x4 7.3L E4OD 3.55 with 215k on the clock. I'm going to start by listing mods, conditions and whatnot before I explain the issues I'm having so here goes nothing!

Mods and maintenance completed in the last year.

1. Fuel filter housing rebuilt and cleaned the FPR. It has a FPR shim installed to get the pressure up to 65psi. (July 2012)
2. Fuel filter has about 5k on it. (July 2012)
3. New fuel pump. (July 2012)
4. New radiator. (July 2012)
5. New Fleet Charge coolant. (August 2012)
6. New intake-Y to intake manifold boots (silicone) (November 2012)
7. 6637 mod. (Feb 2012)
8. Fresh trans oil change with filter and NEW triple disk converter. (August 2013)
9. Tru-cool in bumper. (July 2013)
10. TS switch. (March 2013)
11. 3" downpipe, cat delete pipe, 3.5" cat to 5" exit before passenger tire. No muffler. (September 2013)
12. Fresh transfer case and axle fluid changes. (July 2013)
13. 5k on oil change right now.
14. Full gauge package.
15. Black CPS (June 2012)
16. No Water in fuel light unfortunately as the filter media heater was broken and subsequently removed and the Water in fuel wiring was damaged (until I find a replacement harness)

Turbo boosts to 20psi under load and heavy acceleration, temps are always normal and my EGTs seem good. (going up a 3%-5% grade holding 65 mph while towing 12k on 3.55 gearing nets 1080-1190*, idle goes below 300* normally. Cruising on flatland while towing nets 700-800*)

I can pull off the oil cap and flip it over covering the oil filler port and no blow-by is evident. There is no pressure coming out whatsoever.

From what I know, it has the original injectors in it. I use the Diesel Service grey bottle diesel additive every fill.

The rest is irrelevant so I'll cut to the chase.

I'm towing a 37' 9.5k lb. TT with about another 2k loaded in it . I fueled the tanks at a little fuel station in Colchester VT while on vacation two weeks ago that used above ground small tanks. I was suspicious, but the tanks look new so I did it anyway. I hooked to the trailer and set out for home in VA. Everything was fine until I started to decelerate while entering Lake George, NY when the engine began to give indications of a misfire when the torque converter unlocked. No CEL, no nothing.

I slowed and entered a fuel station parking lot where the engine began to misfire heavily and put out some, not a lot, of white smoke while idling. I began to look for leaks under the hood. I found nothing but a misfiring engine that had a bit of a loud "clack" sound while idling. There was approximately 1/4 tank in the affected tank.(I have had this sound happen before when a tank ran out of fuel while I was idling the truck to warm it, indicating a fuel starvation issue)

I then shut it off and drained the water trap. A very small amount of water came out and I restarted. Idle was still choppy but immediately upon hitting the accelerator in neutral, the misfire went away. Upon idle again, misfire returned. I switched tanks from front to rear, dumped some diesel 911 in both tanks and started driving. Under acceleration, the exhaust looked whitish for a bit but the engine seemed to have good power. After about an hour of driving, the engine was back to normal. Idle was restored, no more white smoke. The thing is, the truck ran great for about 100 miles after the tank of fuel was procured in VT. I have had problems here and there ever since. (two weeks)

Fast forward to today. Driving again, unloaded and all was fine. I decel for a light and the misfire/rough idle returns but immediately is remedied by stepping on the accelerator. Whitish smoke returned for a bit and then went away. While idling at the intersection I noticed the EGT was hovering at 345-350* which seemed abnormal to me. It normally cools back to under 300* while idling at a traffic light) The truck runs great sometimes with a silky smooth idle and other times its rough like its misfiring. I'm stumped!

Please, read the following suspected issues over and let me know if you think my suspicions are correct. I believe I have a couple of problems, but wanted to run it by you guys first before attempting anything.

1. I need to change the oil. It has 5k on it and the truck is ONLY used to tow. It is degraded.
2. The CPS is intermittently, partially failing.
3. There is water in the fuel system.
4. I may have a damaged or unsecured UVCH or valve cover gasket. One looks new, the other, old.
5. I have an injector that is sticking partially open.

Lastly, the dreaded low compression. I have ruled this out due to the nature of my problem. It comes and goes so low compression is ruled out.

Thank you all ahead of time and look forward to your responses!

 

Personally, I would rule the CPS out because the PCM should shut the engine down if the CPS signal is corrupted and it will not fire the engine again until it has good signal from the CPS again. For $26 though, all 7.3 owners should have one just in case and they are handy just to try out for the heck of it.

I'm thinking UVCH, IDM, or water somehow getting to the PCM.

If it was mine, I would put a scanner on it and see what it tells me.. Scan for codes, do injector buzz tests, and contribution tests.

If nothing comes of that I would check the oil level, ohm the UVCH, check IPR connection and tin nut, and pull the IDM and see if there's any water in it. Then go from there.

 

I kind of had this happen to me im not sure if you will have the same problem as i did,you were saying something about your fuel heater was broken,my fuel heater in my fuel bowl was shorting out one time and gave me the same symptoms as your truck is having but i did get a cel and my code was reading something about the cps but i changed it and still had trouble,my truck was running good then all of a sudden it would start misfiring and smoking white bad and keeping the rpm up seemed to be what kept it running and when it was up high enough it ran fine but i couldn't let it idle down because it would die on me,it always started rite back up but it smoked white and ran like crap,i barley got it home that night and the next morning i opened my fuel bowl and found my fuel heater had been broken and touching the side of the bowl so i took it out and undid the the wire in there and left it out and it ran like a beauty ever since,i dont know if you have a wire in there or something to that measure going on but i did get the same issues with mine so i thought id say something anyway to see if i can help at all,i hope you get it going soon and find the problem

 

My vote goes to that one. My truck was pissed at me one morning after a 2,000 mile road trip that put my oil at 5,500 miles. It was low. Changed it and no more problems.

 

This is probably the cause, but you should inspection the VC harnesses to be sure. Also check the fuel filter to see if it is black. If it is that is a sign the injector o-rings are failing and they could be causing you symptoms.

 

^^^^^ +1 oil. We've only noticed it a couple times, but it seems like when the oil is old/weak, you get a significant rough idle specifically on decel / coast from highway speed. 5000 miles towing is a pretty good OCI in any event.

'Course, the suggested inspections are always a good idea.

 

Update:

I changed the oil and filter, fuel filter since it was slightly black, found one uvch that had a bad glow plug circuit on #8 and a glow plug that was open which I replaced.

I bought the compression test adapter from amazon.com for $20 and compression tested it. Showed 340-355 on all cylinders, so thats good. I also moved the CCV so that it vents to the atmosphere instead of into the turbo.

It runs great now. Idle is about as smooth as a 7.3 can get and acceleration is improved. I think I have at least one injector with bad o-rings so I have placed a set of 8 o-ring kits on order.

EDIT: No more white smoke on cold start anymore. None whatsoever. I'm sure the UVCH and open glow plug had alot to do with it.

Thanks everyone for the help. It is much appreciated!

 

Glad your going again. What injector oring kit did you order?

 

http://www.summitracing.com/parts/rn...view/make/ford

 

I hope those o rings hold up for you. Its really best to use alliant orings on these trucks. And they are cheaper than those at riff raff diesel.