Megasquirt - Assistance Needed, Very strange problem Options

[yarin]

I drove the car last thursday, ran fairly rough but had some power. Did some tuning, and had this very odd firing problem. I spent some more time today digging into this, here is what i found:

INJ1 bank hooked up to cyl 1 & 4
when either injector connector disconnected rpm goes up
when either spark plug removed no change

INJ2 bank hooked up to cyl 2 & 3
injector disconnect, seriousl drops rpm

Tried both combos. Alternating, 4 and simultaneous 2. reqfuel 9 / 4.5

So my conclusion is that all cylinders are getting spark, but only two are really firing. Furthermore a quick touch of the exhaust port shows that cyl 4 is running much cooler than cyl 3 after idling for a few minutes. I swapped the cyl 3 and 4 injector drivers and noticed an immediate change in head temp. It sounds like the cyl 1 & 4 are getting fuel, but not igniting. When those cylinders no longer receive fuel, the rpm goes up indicating no combustion, but resistance to compress the fuel.

Make any sense to anyone? I attached my .msq file. I double checked my setting, i made sure i'm only running off 1 table. I just took apart my MS box and can't find any obvious shorts, burns, etc. Keep in mind i'm only looking for this problem at 1000-1500rpm. It's not injector related, its driver related. (IMG:style_emoticons/default/sad.gif)

Anyone?

[DNHunt]

it ran better (I think) on one injector driver, but now you've switched back to two and have flaky injection again? Pretty much proves that the INJ1 driver is bad.

It suggests a problem with the inj 1 circuit including connections. I'd look at continuity and then resistance. Remember the scope looks fine.

Dave

[yarin]

it ran better (I think) on one injector driver, but now you've switched back to two and have flaky injection again? Pretty much proves that the INJ1 driver is bad.

It suggests a problem with the inj 1 circuit including connections. I'd look at continuity and then resistance. Remember the scope looks fine.

Dave

I hooked everything back up to INJ 1 and INJ 2, same weird issues. Idle goes up when injector is disconnected on two cylinders and spark disconnect doesnt change anything.

Ran all injectors off INJ1, idle was very rough, jumped up. Unstable.

Ran all injectors off INJ2, got it to idle OK, still a little rough. According to the timing light cylinders 1, 2 are fouling. 3,4 are OK.

I took data pulling each injector followed by each spark plug. So the sequence of the datalog is 1(Fuel), 1(spark), 2F, 2S, 3F, 3S, 4F, 4S. The start of the event is marked at the following times on the datalog: 148s, 160, 169, 180, 190, 197, 205, 215s.

I expect my AFR at idle to be much higher than where it is now. I think its running rich, which is why my plugs are fouling. When I disconnect fuel to those two cylinders the timing light shows normal spark behaviour. As soon as i connect the injectors back the timing light shows inconsistent spark. Perhaps i'm having injector issues?

I'm stuck.