Setup:
89 dx hatch
Auto to manual conversion
Dpfi to mpfi conversion
Monotech obd0 to obd1 conversion harness
81mm sleeved ls block O-ringed
Forged pistons rods
PnP PR4 head.
Crower 404s titanium valve springs and retainers
Custom ram horn
Precision sc6152e turbo
RC 1000cc peak and hold injectors
GM MSD 3 bar map sensor
Edelbrock intake mani
aem fuel rail and apr
Tuned on crome

Only issue I had prior to our first tuning session was a TPS CEL (#7) which was intermittent and went away with proper calibration.

16deg base timing confirmed

Anyways I got everything running we went out tuned partial throttle then started doing pulls on 7psi (on spring, waiting for boost controller) just to get everything going get a baseline. This is on Crome btw.

So we pretty much got everything tuned on 7psi felt good in that small Hatch for sure!

Coming back home partial throttle started popping and misfiring a bit here and there and we changed nothing on the live tuning at all for it to start acting up. Get into boost it breaks up a little bit and then off throttle I'm throwing big flames popping(hood exit exhaust). Park it for the night.

Next day I drive over to my friends to get a bigger waste gate spring and it starts breaking up even worse and at very light partial throttle too. Pull plugs. Black fouled. Replaced with new (7s, gapped .025). Clears up some for about 5-10 minutes of driving but still light popping/misfire. I'm thinking probably coil? But more symptomatic of an ignitor. I then change the entire dizzy (stock) with the friends known to be working msd cap/rotor dizzy with msd wires and installed a blaster ss external coil.

It runs the exact same. No different at all.

Mind you we changed NOTHING in the tune and it was same weather everything.

Burned a chip to 2 different computers to try plus the tuning computer. No changes.

New plugs nothing.

Mind you it always ends up with rich fouled plugs everytime I changed them.

Base timing is correct. The tune is good (we tune alot of cars) but we don't/haven't used crome in forever. I want to get hondata or neptune maybe eventually but I've never had a crome issue that I knew of in the past.

I'm guessing it's a ground issue
Engine ground? Trans? Battery has good ground...
(ecu grounded 2 feet away to chassis via conversion harness)

Wiring issue came loose somehow???

Bad Injector resistor box maybe?(have rc1000 peak and hold)

Injector sticking open?(Idles perfect though!)

Idles perfect. It's only under load.

Running a MSD GM 3 bar MAP sensor (could be bad?)

2 different dizzy setups and same issue is what threw me off. I could of sworn this was going to be a coil/ignitor/plug wire issue...

I'm lost with what to do next. I guess I need to start tracing every wire in the harness etc and see if something came loose because this isn't making much sense to me.

I'm thinking of buying a cardone replacement stock dizzy and trying that as well. If that doesn't do it I'm not sure what to do after that...

Any ideas?

 

Bump ttt

 

here's photos of the latest plugs I really think it might be on 3 cylinders. #2 plug is dry on the threads.

 

Swap #2 injector with another one and see if problem moves to swapped cylinder.

Do you have power to the #2 injector at all times once ign. is in run, are you getting a consistent ground pulse to the #2 injector. when engine is running? 94