Hunting Misfire...
 

One day car is making boost fine, pulling hard and running really well actually. Then I put on new TB from skunk2 (aka junk2), did the spring perch bs, loctite screws and calibrated TPS with it. With the bigger opening on the throttle body I expected some tuning so I went out and did just that. Beefed up the VE table where it told me "more fuel please". But ever since then I've had misfire that seems to range. At first it was in boost, now its on "tip -in" and when getting above ~110kpa. What the hell happened? I changed a mechanical piece and now it seems like a massive spark cut. (Feels like spark and AFR's go richer/smells rich.)

Things I've checked:
- Unplugged and plugged back in all spark harness plugs. (And cleaned connectors.)
- All grounds tight.
- Timing still on point.
- No boost leaks.
- New coil packs.
- New TB gaskets to make sure no vacuum/boost leaks
- Went over COP harness, all good.
- tested each coil through TS, all clicking.
- Video'd FP and it stayed solid and then moved upward with slight boost, as it should.
- New plugs, same ones that had worked before, gapped smaller, then another set of plugs, gapped higher, no change in misfire.

General Setup:
1.8, kraken manifold, home made downpipe, C(hina)X racing t2860, MSPNP2, walbro 250, FF960cc injectors, Toyota COP's, Aeromotive FPR set to ~44psi. AEM wideband,

Spark Setup:
wasted spark, BKR7e-11 gapped to ~.030" (have tried larger, and smaller gaps, no change.)

I am completely lost and need some more ideas/paths to go down. (someone please tell me it's just something stupid at this point)
Attached is current tune and a log. (RPM's can be seen to 'jump' a little bit.)
I'll do my best at answering questions that any of you may have

Best,
Dan.

What is up with your spark table? It seems to be all over the place

https://cimg0.ibsrv.net/gimg/www.mia...ac8d1a88fe.png

Your AE does basically nothing as well, VE Table is bumpy, may want to smooth out the transition on your spark tables + VE Table and see where you are at.

https://cimg4.ibsrv.net/gimg/www.mia...85c9566f1e.png

May want to grab a spark table from trubokitty that's more smooth and has more resolution up top, something like this

https://cimg3.ibsrv.net/gimg/www.mia...20939f6d70.png

VE table is probably jumpy due to just changing values to see if it helped the misfire. It's definitely a little on the rich side at this moment, but not far off from when it was running strong.
Spark table is the same too, I did dial it back a bit up top when the misfire first started thinking that maybe I had advanced it too much.
I had gone to touch AE just before this misfire and had about 15 minutes to see how it changed as I changed dotTPS so it was "roughly" set up but didn't cause the misfire that's been plaguing me.

I'll try some smoothing out spark table and see where that gets me. As far as AE, do you have any suggestion on where they should be? (The current numbers gave decent reactions from what I remember.)

just a recommendation, I spent a year chasing a misfire in my stock 2001 miata. replaced everything I could think of. turned out to be a valve lash issue. had almost zero lash on the number 4 exhaust valve. it was most noticeable on cold start. may not be your issue, but doesn't hurt to pull the valve cover off and throw a feeler gauge in there to check it out.

It's something to check for sure, thank you.
At the moment I've got the downpipe/turbo/manifold off as I had a pretty big exhaust leak before the O2 sensor, I'm hoping with everything milled flat and sealed, that all of this was just the trickle down of a sensor getting improper data.
But I'll come back if/when I get it all back together.

Just to update everyone on what was going on...

Turns out my mount for the MSPNP2 had failed and the ECU was flopping around with every pull, secured it and its been ripping fine.

So don't be like me, check your ECU mount and make it stout!! THE FIRST TIME AROUND LOL.

You know, I keep seeing this topic in my "new posts" search and thinking:

https://cimg0.ibsrv.net/gimg/www.mia...ecbd65ca16.gif


This thread does not deliver.