Please read this saga and help restore my faith in 7.3
 

Ok, First sorry about the long post, but I want to include all I have done so far to try and fix the start/die problem. THANKS for this great resource! First some history. I loved this truck. Worked it hard. 2000 7.3 xlt reg cab. Bought it with 37k mi, now It's at 237k. New water pump at 170k, brakes and front bearings at 224k, that's it 'cept for a cps or two, and changing the oil every 7 to 9k. Pretty stock, with a four inch straight muffler, a mild three position chip, and BIG air filter. Consistent 21 miles per gallon.

Now I'm hurtin' and would really appreciate any help/advice. TIA. I need my truck for work deperately!

So, it's been about 5 weeks since I went to start the truck one morning and here's what happened, and what I've done so far:

The truck started normally, then about two minutes into warm-up ( I was standing outside toward rear of truck), It coughed, started missing and puffing some grayish, whitish smoke. Ran like that for about 30-40 seconds then died. When I restarted, it would run for two to four seconds then die. Over and over.

First thing I did was put in new gray cps. Exact same result. then I remembered that I had been smelling diesel for in the cab for the last couple weeks. I have to admit that I have not been great with maintenance other what I said above. There has been oil seeping from somewhere. I thought it was the front main seal, cuz there is oil dripping down the front onto the lower rad hose. However there is oil in the back as well and coating the starter, etc...

So I look on top and find oil/ crud/dirt coating most of the engine (looked like cooler tube blowby oil), and a pool of diesel in the valley in front of the pedestal. So... I rip everything out and:

Oh yeah, first thing I did was pulled the fuel tank, cuz I did have an intermittent miss that seemed to be worst at half tank and quarter tank. I thought that the pickup foot had fallen off. To my surprise the plastic tank (1/3 full) was pretty clean considering the miles, just a few flakes in the bottom and the pickup tubes, the foot and the mixing bowl were not too bad at all. So I cleaned it up anyway and reinstalled tank.

Cleaned the valley area (PITA, Rolls of paper towels)

Rebuild ebpv (it was leaking a little, and not working right).

New passenger side fuel line. Almost worn through at bracket, but didn't seem to be leaking yet.

Rebuilt the fuel bowl (it was coated with crud, but couldn't tell if it was the culprit). (Outer filter screen was kinda black, FPR piston also some black coating)

Rebuilt IPR (used old spacer. Warning: I got an IPR kit from NAPA. The spacer was a hair too small to fit. Cheap Chinese O-rings and non anodized nut). Solenoid is a slightly loose, but ohms-out ok.

Cleaned EBP sensor and tube - totally clogged

I found the lower clamp on the driver side plenum very loose. Maybe that's where some oil was coming from?

Ohmed-out wiring harness, injector and glow sides checked out ok.

Pulled only driver side valve cover. Harness still plugged in, but did 25 cent mod. plastic tops of injectors had the black coating like the filter and fpr had.

Cleaned CAC tubes, intake, new pedestal O-rings reinstalled everything.

Nice and clean. Filled HPOP with Prolong.

Batteries are kinda tired, so I charged them. ( I use the top-line Auto-Zone batteries and they always go bad at about two and a half years. Under warranty, so I just buy the same ones each time)

Tried to start yesterday. Same problem still there, but a couple times it ran for maybe four to five seconds. I can only try starting a few times, maybe ten or fifteen times before I have to charge batteries. Looked in the valley after many starting attempts, still clean so far.

I checked connection at chip. OK.

NO codes. No SES. I have an OBD II tool, that has pulled codes before when there was SES.

Again, sorry about this long post, but I just wanted to answer questions in advance.http://images.ford-trucks.com/forums...2/blahblah.gif

Can anyone help?

If it was injector o-ring wouldn't it still start?

Why does it run great for a few seconds?

Air in lines? IDM?

Tried starting with ICP unplugged. Same.

Fuel pump seems to pump fine. Fills bowl fast. Fuel shoots out drain fast upon opening.

This is killing me. If there are any good Samaritans in the Chico/Paradise/Magalia CA area that can help, maybe with AE or??,
I can supply your fuel and beverages at least.http://images.ford-trucks.com/forums.../party0005.gif

MANY THANKS!

UVCH replace both of them. Sounds like what happened to me. It was easy for me to diagnose because I run dual egt gauges. One bank would die and the other would struggle to keep it running. Sounds like you're on the right track.

Two things that would be helpful to know right off the bat would be your fuel pressure with key on and engine off, and your RPMs and ICP while cranking. Also, what scan tool are you using? The generic scanners are very limited with our trucks.

During the diagnosis I would just leave the chip unplugged to completely rule it out.

Thanks so much for the replies. I just came back home and have a little time to play with it. Just tried to start it again about fifteen times. It started each time for two seconds, a couple of times it ran for two or three seconds, loped and ran a second or two more. I never noticed before, but does the fuel pump normally have a bubbly/sucking type sound during bowl fill? Still seems to fill bowl quickly.

I just have a cheap Inova 3030 scan tool. It pulled codes a couple of years ago when the Glow plug relay died.

I don't have a fuel pressure gauge yet.

Maybe I'll pull out the chip, and later I'll pull the pass-side VC. John 01- Should the harness be replaced, or just 50 cented? I got good ohms outside.

Anyone ever tried bleeding air at the head side fuel connections? Prolly be messy.

StillTruckin': I don't have any knowledge to help you, but I am pretty good at asking stupid questions for others more knowledgeable here to answer:

..."Outer filter screen was kinda black, FPR piston also some black."
..."plastic tops of injectors had the black coating like the filter and fpr had."
..."It coughed, started missing and puffing some grayish, whitish smoke."

Did the gray smoke come on all at once?

At 237,000 miles, are those your original injectors?

Does clamping a temp pressure gauge to fuel drain work for test?

Thanks Tim. Yes original injectors. I am puzelled that it sounds good for those few seconds then dies like fuel is cut. Oil pressure comes up good during cranking.

Again just askin' stupid questions: Under your truck at the junctions of the manifolds to the up-pipes any liquid there? A photo would be nice.

I posted something like this to help a fellow van guy get helped better by these engine gurus here at FTE. So maybe it could help you also.

Maybe posting a video showing the upside down oil filler cap blow by test. Also a video (with audio) showing you start the engine and letting it run with the camera pointed toward the open engine bay would help. Getting, a friend to stand outside and video the passenger side as you drive towards and away from the camera would be good also. Finally, a video shot of the exhaust pipe as you start the engine and then raise and let off the idle a few times could be instructive. As I told the van guy, right now you are asking these engine gurus to imagine how it runs. With photos and especially video they can actually see and hear how it runs. Saving them and maybe you some time. Just a suggestion.

I'll get back to this later this evening, gotta run, but thanks again.

Another thing. I used to really know the smell of raw diesel fuel years ago from running equipment but it has changed. The fuel I've been draining is very light green with a light varnishy smell. Maybe bad fuel? I'm grasping at straws here.

I did the 50 cent mod and it didnt fix my problems. Finally on the last try I replaced the uvch and problem solved, I took the old harness apart to "investigate" and it wasn't until I broke it beyond repair that I found the real problem.

I wouldn't put money on it at this point but we are trouble shooting too, do the free or next to free things first. Can you hear your fuel pump kicking on when you turn the key over? My fuel pump went out a few weeks ago and under normal driving conditions with the exception of the SES light all seemed normal. I had a strong vacuum from the tank feeding the engine.

Given the odd fuel, any chance you got gas in it? The internet truth I read here goes like this: put some of the fuel in a styrofoam cup. If it dissolves the cup it has gas in it.

Also, does the SES come on when you first key on the power? Just to check if that lamp still works. You may have codes but the dash lamp is dead.

Assuming the lamp is good and really no codes I'd suspect fuel issues. When you cleaned out the tank did you remove the white mixing chamber? The screens inside may be clogged. Fuel pump is a suspect too. As John mentioned, does it sound steady and strong for the 20 seconds or so when you key the power on?

We'll get this sorted, no worries. :-X22

This has been sticking in my proverbial krawl all day since I read the the original post. How can you title a thread asking to restore your faith in a truck that you admit you got 200,000 miles out of after all but neglecting it? If you have done nothing but oil changes a few CPS's and no other basic maintenance, and got 200K out of it, how could your faith ever be shaken?

Agreed, subscribing.

Thanks all for the replies. I cleaned the mixing chamber in the tank first thing, as stated in the top post.

As far as the faith thing, ya, I know. I just became frustrated. I've worked on large truck and tractor diesels, and was a little surprised at the somewhat complex setup in the Ford. Now that I've been into it, It does seem a little easier now. I just wish the cab/hood tilted forward...ha ha. (not lol)

I always had confidence in this rig, and hoped I could get the miles from it that some folks experience, ...upwards of 400k and beyond. There was an old crew cab, I think it was a '90 on one of my jobs that had close to 350k and was beat to hell, but kept on going strong engine and drive train wise.

Thanks again for the suggestions. Just seems like it wants to start ( again it does start and sounds fine for a few seconds) and the pcm, or something says "Nope , stop, not gonna do it"!

I'm kinda scared to buy an ICP, or a fuel pump, or an IDM and/or take time to tear it down again and to change harness, or etc... , when maybe it's something else.

The fuel pump sounds ok, and fills the bowl, but I don't know about the static pressure.