Ran great, then smokey and down hill... - Diesel Forum

Super_Dave · 06-26-2008, 05:27 PM

Well, after replacing a few things over the past few weeks, I started getting my mileage back up to what I had when I got the bus, '96 E350 dually. I had tanks back in the 11-13MPG pulling my 24ft enclosed trailer.

Things were good, then seemed to drop off rather abruptly. Kind of a blue smoke at idle and above, then black smoke trying to stay at interstate speed. Engine ran warmer and wouldn't maintain the speed I would like to. Mileage dropped to a consistent 7MPG. Made it feel like a 7.3 non turbo motor or like it dropped several cylinders.

I almost ran the tank out, and I'm hoping in many ways that I got a bad batch of fuel. I think my tank has a drain, and I might try getting everything out after that.

I've never had any injector service on it. With 256k, and no knowledge of what was serviced on the bus when it was used by Belleville Area College, I've been wondering what might happen. Would the injectors or the o-rings finally go out and fail? I had deteriorating performance over a period of time, but then it recently bounced back, now dropped very low.

Thoughts would be appreciated.

blageurt · 06-26-2008, 05:56 PM

Mayby the lift pump is going south. I have to change mine soon too . Chech your pressure and the FPR screen. I had to clean mine last week after about 20, 000 kms . I aslo will swap my Turbo while I'm there. I also had similar issues , changed my Map sensor and got marginally better . I am also sending the feline on a one way trip, never to return. I've been very busy so I haven't gotten to it yet but I will do everything at once . Fuel pump /Turbo / feline vacation / guage install etc. etc. I need about a week of rain . . .

Super_Dave · 06-26-2008, 06:02 PM

I have a recently replaced screen, and I recently shimmed the FPR. At idle, I was around 65psi.

blageurt · 06-26-2008, 06:33 PM

Are you making normal boost?

Super_Dave · 06-26-2008, 07:09 PM

Quote:

Originally Posted by blageurt

Are you making normal boost?

I don't have anything to measure that. I can hear the turbo, but that's all I can say.

blageurt · 06-26-2008, 07:22 PM

I would get a guage and install it as soon as you can. Also take the dog house off and see if there is any sooty deposits where the donuts are on the up pipes. They can leak causiing low boost issues. That is why I am installing a rebuilt Turbo and upgraded intake hose. The orange rubber ones tend to flatten out under high accelleration. That would explain the poor economy and black smoke. Not enough air. Right now I am making normal boost (14-17 psi max ) , but when I do my upgrades I should see higher numbers. I would start there. Determine what your boost is and go from there. You can get a cheap guage for about 50 bucks on e-bay . Double that for a good one. It sure helps in diagnosis thats for sure. Good luck.

Super_Dave · 06-26-2008, 07:32 PM

I do still have the orange hose. I actually just got the new black one a couple weeks ago. Hard to access everything on a van to do it all quickly between events for me.

Certainly, it might explain the black smoke on boost, but it doesn't help explain the blue smoke at idle that came with it. Or does it? I've certainly ran her harder over the 86k that have used her to pull my trailers, so I would be surprised if the hose would be the cause completely.