Strange problem

[wildhorsesracing]

Howdy all,
We have finished our car and are ready to do some serious testing. We have had a small problem with the engine running, it runs very rough and stumbles.

We have a megasquirt MS3Pro from Wayne @ Very Cool Parts since it is an 818R and will not need anything more than that.

We can pull the injector wiring and/or coilpack wiring for cylinders 2 & 3 and it has no effect on the engine running. We have swapped in new injectors, new coilpacks, etc. but still no change. We had replaced the timing belt when the engine was out. Our local engine builder said it is easy for it to jump a tooth when reinstalling so we pulled the cover off today and reinstalled it - but it turned out to be right on the marks to begin with.

We have checked the wiring and it seems to be fine, is there any way to verify the megasquirt is sending the proper signal to the coilpacks/injectors?

Any ideas?

[Bob_n_Cincy]

Is it possible you used a wrong chart to wire your cylinders.
Here is a Subaru.
Bob
clyl.jpg

If you thought it was

3 1
4 2

Then 2 and 3 would be swapped.

[wildhorsesracing]

That came pre-wired in the package from Wayne @ VCP. We simply connected the harness to the various connectors on the engine. We did trace it out and it seems to match what the settings are in the MS3.

[michael everson]

Ok this is a long shot but I had the same problem. Seems when I powdercoated my valve covers they then had a bad ground to the engine. I think my coil packs grounded through the hold down bolt that was in the valve cover. At least that's what I think my problem was.
Mike

[wildhorsesracing]

Finally got it running on all four cylinders! We found out that everything was firing, but it was firing all at the same time!! Found out the issue was with the megasquirt wiring that came from VCP. Spark A-D and Injectors A-D were wired in sequential order cylinders 1-4...when it was supposed to be wired in firing order! Firing order for 4 cylinder subaru is 1-3-2-4, so we swapped the pin connectors for 2 and 3 for injectors and spark and it runs perfect now! This is a picture right before we do a dyno run to tune it properly and make sure it is ok to go on track!

dynotune.jpg

[Bob_n_Cincy]

Is it possible you used a wrong chart to wire your cylinders.
Here is a Subaru.
Bob
clyl.jpg

If you thought it was
3 1
4 2
Then 2 and 3 would be swapped.

Great news.
Do I get a prize?

[wildhorsesracing]

The Megasquirt programming had the correct firing order but it turns out for Subarus you need the wiring out of the ECU to match the firing order.

[indiana818]

i may have the same problem how did your engine run at first my engine seems suoper rich and back fires

[indiana818]

what wiring and where did you switch? i need to check mine

[Mechie3]

One easy check is the color of the plug on the coil pack. 1960's segregated bus, white in front, black in back. Remember your history and wire the car right. Forget your history and it backfires. Might not be your problem, but an easy thing to look at.

[metalmaker12]

Cool you got it running right!!