Thread: Passed Smog, but now car runs like crap

So I finally got my car to pass Smog, even though it's running like crap.

Setup:
96 200sx se-r
sr20ve
N1 cams
JWT ecu
DE dizzy
DE TB
VE Injectors
N60 MAF
20V header
MSD 6a ignition
MSD RPM switches

Car was running good, but I was getting a CEL (IACV code) because I was running a ga16 JWT ECU. I needed to pass smog, so to get rid of my codes, I swapped out a stock ECU, DE injectors and DE MAF. After I swapped those parts, the car idled fine, but when I drove it, it had major hesitation issues when going into VVL or anywhere near WOT and a little bucking at low RPMs in 2nd. It revs smoothly when in neutral.

I kinda assumed that my car was running badly because of the parts I swapped out, even though I thought it was supposed to run ok like this... so after passing my smog, I swapped those three things back, MAF, INJ, ECU, and I've still got the same hesitation issues. I've double checked my ignition timing, 15 BTC. Spark plugs were changed a few weeks ago.

I thought it may have been my MAF wiring as I crimped some quick disconnect spade connectors for easy swapping of the MAF. I cut those off and twisted/taped the wires together, but that didn't make a difference. MAF has not yet be regrounded to the intake mani, will do that later.

Any suggestions or things to check? I've got a consult cable if that helps.

After doing a little more checking, it seems that cylinders 3 and 4 are not firing. I pulled both the 3 and 4 plugs and no change in idle. I could see that it was getting spark. I'm thinking of replacing the distributor cap and rotor, I leaked some fuel in the distributor cap the first time I pulled the injectors before this started happening. Does that sound logical?

Could have fouled out the plugs. Pull the plugs and check them out.

Well I checked voltage at the injector plugs, had 12V common across all 4 plugs. Inspected the wiring at the ECU connector, tested continuity through each injector signal wire from the ECU to the injectors. Pulled the fuel rail and turned the motor to verify all four injectors are spraying. Cut back the wire loom on a couple suspect looking sections of the injector harness to check for damaged wires. Inspected and cleaned the dist cap and rotor. Couldn't find anything wrong, so I put it all back together and now it's running on all 4... I must have had a bad connection somewhere.