85 eta rough misfire black soot from exhaust

[2.5-12]

I'll swap to the AFM from my DD ETA and I'll adjust valves to .010" to check it out


next on the list is swap everything over to SuperETA electronics since that would at least give me a damn Check Engine Light

[crazyman]

I just thought about it. When my afm went out it affected the whole rpm range except idle. It was really noticeable at wot. Hope it helps, I'll keep scratching my brain and let you know if I come up with any other ideas.

[2.5-12]

I noticed you never mentioned changing the timing belt(you did mention checking timing though)or having adjusted the valves (I read this thread twice just to make sure). From your post it seems you have been very thourough so it seemed odd you hadn't mentioned these two things, unless you havn't done them. The valves could have changed after a recent adjustment due to wear on a high point on the eccentric (completely new thing to me, I'm use to adjusting nuts and timing chains now I get to learn about belts and eccentrics).

I really don't have enough experience to even know if either of those two things would cause the symptoms in these cars, but they have been related in other vehicles I've owned and some I still own. I always change the timing belt, so far (knock on wood) I havn't experienced any belt related issues. Just thought I would throw it out there. My thought was eliminate all variables.

If these symptoms are completely unrelated to Valve adj. and belt I appologise for noob post and cluttering up the thread.

Ranx

I did change the belt and tensioner, I recently re checked my timing marks and belt tension

no such thing as clutter in a thread like this -- any help is appreciated. :)

I know you said earlier that you swapped afm, was that one from your good running ETA? If so was there any change in how the engine was affected?

I swapped two ETA AFMs in from my parts pile, I should try the AFM from my good running ETA that's a good call.

the engine changed maybe a tiny bit between AFMs, but always ended up running and behaving just as poorly in the end.

[crazyman]

I know you said earlier that you swapped afm, was that one from your good running ETA? If so was there any change in how the engine was affected?

[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.

[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]

o2 sensor change had no effect

[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

[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]

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]

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]

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

[dnguyen1963]

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

[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]

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.