85 eta rough misfire black soot from exhaust

[dnguyen1963]

Ahhh...but that is the life of an E30. Everything is running perfectly until you play with the engine. How many times have we heard..."but it was running perfectly until I replaced..."?

[2.5-12]

in all fairness, I did replace a lot in one go.. bad idea.

since replaced a lot more than that even. whew.

some day it'll run right, even if I have to convert it to Motronic 1.1 to do so.

[dnguyen1963]

I feel for you...but seriously, put in a new set of injectors might solve your problems.

[2.5-12]

well, shit.

swapped fuel rail, fuel injectors, FPR from my perfect running ETA and it still runs like a big pile of donky faluces.

pulled off the upper timing cover to check timing, that was a-ok.

swapped distributor cap, wires again too just to check. nothing.


car still hard starts, will die if accelerator isn't prodded gently most of the time. If I unplug the ICV, the car will idle search but it won't die. when I do this, exhaust is visible. assuming rich fuel mixture.

I think I have now replaced everything.

what. the. fuck. is this car trying to do to me?

[dnguyen1963]

Damn...what kind of injectors are in your car? Maybe, the injectors and the chip are not comparable. Have you put all stock injectors and DME back in to see if it would run ok? You have replaced so many things already.

[2.5-12]

Damn...what kind of injectors are in your car? Maybe, the injectors and the chip are not comparable. Have you put all stock injectors and DME back in to see if it would run ok? You have replaced so many things already.

all stock 19# low impedance EV-1 injectors from ETAs

I will try a couple more DMEs just in case on these injectors, but they came out of my DD E30 which ran perfectly.

[dnguyen1963]

Put 14# injectors in the car to see if the problem persists.

[2.5-12]

out of what? I don't know of any other cars that use low impedance injectors.

[dnguyen1963]

Sorry pal, brain fart. I forgot you have an ETA. Yes, ETA requires low impedance injectors. The only other thing that I can think of is that your engine might be running in a closed loop. Might be worthwhile to check the O2 sensor to make sure that it is working ok and let the engine run in open loop once warmed up.

[2.5-12]

I suppose I should.

its a brand new o2, but even new parts fail.

smoke tested it today. tight as a drum, no hints of a leak anywhere which is good. swapped all 4 sensors on the thermostat housing, dumped a ton of premium fuel and injector cleaner in the tank.

car still runs like turds.

took it out on the road briefly, and it stumbles pretty hard under WOT acceleration actually which I didn't notice before -- so thats a new symptom to maybe help trace this issue.

I just yanked my other M20B27 from my winter car that ran perectly, which is where all the parts are coming from, that car is getting an M50 but I want to make this damn thing run right!

havent tried another DME again. want to try a third green idle box just in case too. I'm at a loss. this is confusing.

[dnguyen1963]

Check the O2 wire connector and make sure there is no corrosion or loose wires. That connector can, sometimes, give us a lot of headache. What does your tach needle do when the engine stumble?

[2.5-12]

slowly falls while the engine stumbles then either climbs back up if the idle air compensates or it falls to zero as the engine dies.

will replace o2 with the one from my decommissioned eta

[2.5-12]

o2 sensor change had no effect

[dnguyen1963]

I'm out of idea...maybe Jlevie can chime in. The only other thing that I can think of to try is to take the injectors out, connect each to a 12v power supply, and monitor how much fuel is being delivered per each injector per time (5 - 10 min). If all injectors behave the same then it's got to be how the DME is metering out the fuel.

[2.5-12]

the injectors I swapped in were recently rebuilt/flow tested.

I'll chuck in a different DME just to see if the o2 circuitry is bad or something. this car is a lost cause. may have to part it out after all since no one wants to buy a car that doesn't run right.