2jz-ge swap and ignition miss HELP!!

[NokaoiMK3]

So I swapped a 2jzge from a 92 lexus sc-300 into my 90 mk3 supra.. Here is what is happening.. It idles fine and revs up pretty good and smooth tilll about 2500 rpm then starts breaking up very similar to like a 2step.. If you hold the throttle it will still keep breaking up but will still rev higher in the rpm's even tho it is breaking up like crazy.. Same exact thing when free reving it and when driving it down the street.. Here is everything that has been checked and gone over so far so you can eliminate it from the potential causes..

-New timing belt and engine timing is spot on and has good compression
-Ignition timing is set to 10 degrees BTC at idle on the #1 wire
-New TPS sensor
-New Distributor cap and Rotor
-New plug wires
-New ngk platinum plugs tried gapped at oem spec .043" and gapped em down to .030" and pretty much same result mabe a little better with tighter gap
-Listened to injectors with stethoscope and all seemed to be clicking the same so no stuck injectors
-Ohmed out ignition coil and it checks out
-New maf sensor
-Stock ecu and complete wiring harness

Any ideas of what else it could be to be causing the ignition miss???? Im just about out of ideas

 

[turbodriz]

yeah if you are running a 7m wire harness and computer check all of the fuses with a test light. sometimes they look good and there not. sounds stupid but i seen it happen with a 7m motor. same symptons.

 

[hottscennessey]

have you checked codes yet?

 

[mkiiichip]

Do you have a fuel pressure gauge?

 

[NokaoiMK3]

yeah if you are running a 7m wire harness and computer check all of the fuses with a test light. sometimes they look good and there not. sounds stupid but i seen it happen with a 7m motor. same symptons.

Im running the stock sc300 engine harness and ecu.. What fuse could cause the missfire?

---------- Post added at 09:32 AM ---------- Previous post was at 09:31 AM ----------

have you checked codes yet?

Yep and funny enought its not given any codes

---------- Post added at 09:35 AM ---------- Previous post was at 09:32 AM ----------

Do you have a fuel pressure gauge?

I do.. Thing is is that its the walbro that i was just running with my 1jz with no problems.. Its the stock fpr on this engine tho.. Ill check the fuel pressure and make sure its in spec but i dont think the fuel is my problem just because the plugs have some black on them (not alot) you can wipe if off with finger its not like a carbon buildup but it does look like the engine is running rich..

 

[Albert]

Sorry to bump this thread but this same engine got swapped into my daily and I'm having the same issue again.

It's random, some days it drives fine some days it's got a bad misfire.

I'm running the 7mgte maf. Not the 2jzge maf. Any issues?

 

[claytonwes_2]

Are your valve cover gaskets good?if they leak they can fill the spark plug galley with oil and cause issues with ignition.
Sent from my LG-C900 using Board Express

 

[Albert]

Yeah I checked that when I replaced the spark plugs, bone dry

 

[Albert]

Still have this issue!

Ill set my TPS and unplug my maf, reset the ecu and set my timing at 10deg

It goes away for a week then comes back.

I have a code for oxygen sensor...but idk if it would cause the bucking it does?

Seems to be harsher in the mornings, and more of a slight miss when it's warmed up...

Getting really fed up with it, I may look into putting it up for sale

 

[Albert]

Another thing is it is on a 7mgte maf, which as we all know are paired with 440s..... 2jzs come with like 320s.

Maybe a lean breakup?

 

[Albert]

I'm running the 22204-42010 maf which is 7mgte

I think I need to be running the 22204-42011 which is the 2jzge maf

 

[Albert]

Okay I think I fixed this thing for now; only time will tell.

The ecu was a California based ecu, harness is not. I got anther ecu that wasn't a California spec ecu. I no longer have an engine light constantly on.

I also replaced the maf with a 2jzge maf instead of the 7mgte one

And I put on a TPS that has the correct part number for a 2jzge. The other one had no part number...

 

[Albert]

Did not fix the issue.

The issue was a loose wire in the distributor plug (harness side)

So far months without a single hiccup