Massive fuel consumption, bogging out, white smoke, possible computer failure?

[Tim]

http://www.turbododge.com/forums/f4/...gging-out.html

I have a topic going on this over at turbododge. The problem started a few days ago, although it came and went a couple times in the past 2 months.

I've tested out the MAP, O2, fuel pressure, and some other things, the injector ground / power leads seem to be ok, but the problem seems to be injectors 1 and 3 dumping HUGE amounts of fuel into the engine. Lots of white smoke and fuel dripping out the tailpipe.

I was able to swap around a few injectors, and the problem pretty much stayed in 1 and 3. I had a Code 27 injector driver failure come up in my Check Engine Light before I reset it by taking the computer out to clean and inspect and test the grounds.

Engine is a stock 2.5 Turbo, with a 2 piece intake and LWP aluminum fuel rail. Chris at turbosunleashed was just telling me about cracked mounts on the rail, but my mounts are fine.

Any new ideas appreciated!

[shadow88]

Replace with known good computer is my best guess unless you're going to complete the diagnostics for the injector driver circuit.

[Tim]

Got my new set of free warranty replacement injectors at pep Boys today. Put them in, and the car mostly ran better. #3 still had a wet spark plug tip. But the engine idled smoothly for a while.

I'll try switching injectors 3 and 4 and see if the problem moves with it.

I REALLY don't want to start cutting into the wiring harness and running individual ground wires to the computer, but I may have to.

[Tim]

Found the solution. I pulled the #3 injector plug off and left it hanging there. I went to the junkyard and got a couple other injector plugs. The rectangular ones from the 3.0 V6 fit fine. I also got a bunch of wire out of the rear door of a Caravan.

I made new wiring for #3. I ran a positive power wire to the battery, and ran a negative wire to pin #14 in the ECU, a few inches from the main plug. This unit has 4 injector ground wires, so it must be true multipoint.

Once I did that, the tailpipe smoke stopped and it ran nicely.

I'm still getting a lot of white smoke from the turbocharger area. I had the fuel rail off and on at least a dozen times, so I'm guessing some gas and oil got down there and it taking a long time to burn off.

I see about 5 inches of oil along the braided turbo oil line, I hope it isn't leaking! I just changed the valve cover and the new one isn't sealing perfectly, but I can't see how oil got all the way back there.

More testing and another oil change tomorrow, this thing had better work right!

[cordes]

Glad to see that you are making progress. You should be able to rebuild your injector wiring harness fairly easily if you need to. Keep us updated.

ETA: If it is a SMEC it is not sequential. If you need wiring diagrams I have the 89' FSMs so I can scan stuff for you.

[turbovanman²]

As cordes said, SMEC's are not SFI, they are batch fire, I believe its 1+2 and 3+4. I would rebuild your harness, you can buy the inj connectors then simply wire up a new one, I did that when I built my TIII, made a new one.

[Tim]

It is not an SMEC, it it an SBEC, a single 60 pin connector. The previous owner swapped in all 1990 wiring for the whole car when making one good car out of 1 good one and one worn out one.

I was thinking of making an all new injector harness myself. I'll leave the wire in place for the knock sensor, not that it does much good, and run a whole new set of wires to the battery / ECU area. Wouldn't be hard for me to do.

[cordes]

If it's an SBEC, then it is definitely sequential. You should really only need to rebuild the injector portion of the harness from all I've seen. Also, the stock knock detection in our cars is pretty good.

[Tim]

Drove a little over 100 miles tonight, everything worked fine. I may make a new injector harness for all 4, but then again, I'm thinking "if it ain't broke don't fix it".

We'll see.