Misfire like hell
 

Help.... I upgraded to the high res code a week back and the car started misfiring occasionally. Now it's always dragging a cylinder and I suspect it's a MS setting. Please take a look at my MSQ and let me know if something looks amiss.

I'm running 460cc RX7 injectors and COPs. I suspect this is a setting issue since I discovered at least 3 so far that did not carry over to high res in my MSQ. No idea why.

well... I just went through and double checked all of my settings against an old MSQ... apparently high res didn't take my code wheel settings properly. 2nd trigger was disabled and it had the wrong wheel style, the fact it's been running at all is amazing.

Time to order that test pipe, I have a feeling those two dragging cylinder have probably fucked the cat.

Check the oil too. Its probably contaminated with fuel.

new MSQ for you to look at. now that I've fixed the wheel settings it won't run at all. I can get it to start, but then it dies a second later and backfires like a mofo. these settings were working fine on the old code.

I need to drive this car to work tomorrow... so help is greatly appreciated.

did you plug everything back in? map line still in there?

reburn another old map. certain the flash was good?

everything is plugged in solid and getting readings in MS.

my old maps are no longer valid as I'm using a stand alone CLT that actually gives me valuable numbers (the old one read 215 anytime it was over 90*).

My old maps are pig rich in high res due to the CLT change.

I reflashed the new code 3 times with the same results, even though easytherm told me successful each time.

I just pulled the plugs and fuel vapor was rolling out like steam from cylinders 1 & 3. I pulled the plugs last night due to the progressively deteriorating misfire and they were all clean and looked perfect. This time cylinder 2 looks like it's stupid rich, 3 is mildly rich, 1 & 4 are still perfect. The engine has run for less than 4 minutes since I pulled them last night.

Possibly failure of MS coil driver?

i had to pull like 10 points of fuel throughout when i went to 10g, otherwise, no issue like this.


wanna try my map?
Attachment 7491

I just flashed standard code, I'm going to see how it reacts to an old MSQ on the low res code. If that runs then I'll go back to hi-res and dump my maps into your MSQ.

same shit in low res. I'm can't tell if I'm dragging one or two cylinders... but it definitely runs like shit.

I just swapped the plugs out for new ones before this start-up so that isn't it. I just had the fuel rail out to powder coat the manifold. I'll check there first (it didn't misfire nearly this bad before I pulled all that stuff off). I'm think'n this may not be MS related unless it's a failed/failing injector or coil driver.

Ugg...time to put spark plug wires back on :(

well.. wiring all checks out. (pulled the harness and went through it with a multimeter and inspected for insulation gaps)

I also ran a compression check to see if I toasted the rings/valves. All cylinders came back 175-180.

*edit* put the spark plug wires back on and hooked up the timing light. cylinders 2 and 3 are strong. Cylinders 1 and 4 aren't getting shit. harness in the engine bay checked out so it's time to go back to the MS.

MS and harness both check out. I'm clueless as to why only 1 & 4 will not fire. Damn it.

Ok... I rewired the whole fucking mess (despite not being able to find a problem). Obviously, the issue is still there and I wasted my time.

I also plugged the ignition into the stock ECU (MS still running the big injectors), and the stock ECU produced the same misfire condition. Cylinder 2 & 3 hitting every stroke... Cylinder 1 & 4 not getting any love at all.

At this point I'm suspecting I somehow managed to fry two coils at once. I lose because the wiring is epoxied into the coils.

So... Anyone have a set of COPs with the plugs lying around?