Sorry i was using a phone to write post now i will re right it and explain it better.

I swap a 97 jdm gsr into my 2000 civic cx using a 2000 honda civic wire harness. I was using a p72 ecu that came with the motor using a obd2a to obd2b jumper harness.

I wanted to tune the car so i went to a local tune shop tech told me i needed a obd1 ecu to tune the car i was in luck he had a p28 ecu with chrome and a obd2b to obd1 jumper harness.

He ran the car on dyno did some pulls than this is where the problem began once my car hits 4500 5000 rpm once coming to a stop the car has a miss fire idle problem and shuts off. yes this only happens once i pass 4500 5000 rpm.

If i swap back the p72 obd2a to obd2b jumper harness car runs fine once passing 4500 5000 rpm coming to a stop car idles fine.

I took it to another shop he did the same pulls he used another jumper harness another ecu and did the same thing car shuts off once passing 4500 5000 rpm.

He hooked up a s300 ecu ran it up to 4500 5000 rpm came to a stop and the car didnt shut off.. any ideas this guy says something to do with wiring in my civic si wire harness....

 

English please? Your tune sucks and you may have a mechanical problem.

 

make sure the conversion from 3wire to 2wire iavc and put the car on the dyno or something chips with unknown tunes dont always work imo

 

If you're not getting any CELs with the stock ECU, it's either a bad ECU or a bad tune. Most likely a bad tune. A GSR requires a very skilled tuner to operate correctly on Crome, especially if you're using the IAB manifold.

 

does it only happen after you hit vtec? try this, take a jumper wire and connect pin A4 (VTEC) with pin D6 (Vtec pressure switch) on the jumper harness

 

please read new post thanks for the reply hope this helps..

 

yes this only happens when i use the p28 ecu with obd2b to obd1 jumper harness when i use the p72 ecu with obd2a to obd2b the car is able to pass 4500 5000 come to a stop and idles normal

 

I will look information on how to do this since I didn't touch the 00 Si harness there are 3 plugs that I did not plug in. I also swap out the intake manifold to a Skunk2 manifold .