Thread: Gtir swap.. Having some trouble at the end

Hey guys I completed a gtir swap s3m cams, z32maf,72lb Injectors from JGY, and running jwt b13 ecu tune, in my 95 200sx (b14) everything plugged in. It runs but when I try to floor it it will not go . It bugs out at like 2500-3 I've played with it. There's no vacuum leak. The gauge read 15psi at vacuum. Than I read on the forum to swap the 2 outside wires on the tps. That made my car worse! Now it's acting up. Winter start w/out gas pedal assistance. It's runs very LEAN!! 14.5-16 bouncing all over the place. When I rev it goes down to 11ish-12 and release pedal it raises to as high as 20-21. Than Slowly goes back to 14.5-16 and bounces again. Please help!!

So to clarify...

Model Series: B14
Engine: SR20DET 54C
MAF: Z32 N62
ECU: JWT B13 (OBD1 Blue Plug)
CAMS: JWT S3M
Fuel Injectors: MSD 72/lb
Fuel Pump: ???
Fuel Pressure: ???


TPS Voltage @ Closed Throttle: ???
TPS Voltage @ Open Throttle: ???
MAF Voltage @ Key On Engine Off: ???


What are you using to determine Air/Fuel Ratio?
Were you able to get the engine to run proper prior to installing the JWT S3M camshafts?
When installing the camshafts, did you secure the timing chain to the camshaft sprockets?
Did you verify proper shim clearance after installing the S3M camshafts?
Is the MAF wired in properly - Solder/Heat Shrink or with wire crimps?


Pics always help.

I cannot ever understand how you guys can trust JWT with a turbo tune on a ecu. Every car and engine and conversion is different, to put a list of parts on a engine, then get a tune from JWT and expect it to run a turbo engine safely (or even at all) is madness.

Im not knocking JWT, there seems to be a lot of people out there that are very happy, and im sure if they were blowing up engines all over the place they wouldnt be in business.

But if i was investing in a what is now getting rare GTIR engine, no way would i try to boost it on a off the shelf tune

I doubt its the jwt ecu.
if you are running the correct maf/injs for there tune then u shouldn't have a prob with the ecu.

sounds to me like a bad MAF or the wiring to MAF is incorrect.

deff ck the maf output voltageto see if its in spec.

gonna have to look into that TPS wiring also.

just so you know, when the rpms are going down cause your foots off the throttle and the afr says 21.00 its because theres no fuel going into the engine at the moment.. thats completely normal.. and 14.0 - 15.6~ is ok for idle, i try to stay 14.7-15.0 though


Are you venting the bov to open air or is it recirculated into the intake LIKE ITS SUPPOSE TO BE?

Or are you running blow through?

im a pretty firm believer in draw through w/ recirc bov when running a maf, thats just my personal preference.

Did you wire resistors in for those 72lb inj? Post some pics of the engine bay... Sounds like more then one issue.

Thanks guys. Ima take everything apart and check it all. And I plan on getting nistune but as we all know money is a problem sometimes. Haha. Got the jwt tune just for temp for this season.

Ok so figured out that what I read online was what made my car worse! Do not flip the 2 outer wires on tps. And now running better not 100% yet but she's a beast. Just needs a good ecu and a Dyno

You need to verify the ignition timing first and go over all the maf wiring.