Hatch It

It's been years since i posted here, well i'm back with a 96 EK and have some questions i could really use help with.

So it has a B18C JDM GSR swap from Hmotors, with a P28 ecu to OBD1 conversion and Rywire tuck.

Wikipedia says rev limiter should hit at "8484-8550 RPM's depending on the model" but i am noticing on my EX cluster that it's cutting fuel at a little over 7k. Is this the correct ECU for this swap? Because i'm hearing a P72 ECU is what this motor typically is ran on..

Also the GSR intake manifold has the second butterflies (IAB) and i read with OBD1 there is no wiring for this, yet i can still hear them open up at the 5700 rpm mark..

Just sort of confused right now with how this swap was wired. I plan on chipping and tuning the motor soon after a few more mods, but want to make sure that the P28 OBD1 conversion with this motor isn't a problem and is the correct ECU for this motor, i also read chipping and tuning a P28 is easier anyway.

Anyone care to shed some light on this for me that'd be great!

Hatch It

Also should i be running a P72? And would a P72 run on the OBD1 RYWIRE harness?

Some threads said a P28 wouldn't run a B18C yet mine is doing fine, maybe they mean on an OBD2 setup?

n/a2boost

My guess is the p28 ecu has been chipped and either a base map or tune was done. Open the ecu and see if it's chipped. I wouldn't run it if it hasn't been chipped.

The rywire harness should have been set up for that motor in that chassis when ordered,or the iab was wired in seperate.

Hatch It

It does run really good and pulls very hard. So my instincts tell me it's chipped. But i will crack open the ECU tomorrow and look closer at the IAB wiring.

Now in case the ECU is not chipped and since it's converted to OBD1, would I be better off just chipping and getting the P28 tuned or finding a P72? And is the P72 just plug and play for the JDM B18C on an OBD1 harness?

Thanks for the reply

n/a2boost

The p72 is plug and play for an obd1 set up and would be the cheaper of the two option. The p28 with a chip and tune will run your set up but costs a lot more.

Hatch It

So i checked and it is in fact an unchipped P28...

What doesn't make sense is the IAB's are opening at the right RPM (5600), so how could this be with an ECU that doesn't (from my knowledge) support the IAB manifold?

I guess i'm on the hunt for an OBD1 P72? Or is there no difference and any P72 will work?

Hatch It

Anyone? I searched and really want her running right ASAP. Although she runs strong i know it could be much quicker with the right ECU..