I just got a B18C5 from a '97 ITR swapped into my '98 GS-R and there are two problems.

1 - On a cold start I turn on the car but it would die instantly. I am able to keep the car running by holding my foot on the throttle and if I let it warm up a bit (not up to operating temp) after 2 minutes of keeping the engine at 2000rpm it would idle fine and not die. A possibly related problem is after an hour or so of driving the CEL comes on and the car will have a sort of rev limiter around 1500rpm, but apply more throttle and you jump up to 1800rpm. Failsafe/limp mode?

We tried:
- Cleaning IACV (but will try again, and switching to GS-R IACV)


2 - I cannot feel the VTEC crossover at all, the car goes through the revs very smoothly like an LS motor. According to a shop owner (not the people who did the swap) the car feels underpowered for what it is.

We tried:
- Hardwiring VTEC
- Switching ECUs to GS-R (same result)
- Switching to GS-R solenoid (ITR solenoid works also)


Specs of motor:
B18C5 (1997 CDM ITR)
Ported and polished head
Spoon headgasket
BLOX stage 1 cams
Mugen retainers
JDM ITR pistons
GS-R exhaust manifold (I will replace it asap!)
Exedy 9lbs flywheel
Exedy stage 1 clutch
P73-c02 ECU
OBD conversion
Idle set at 1000rpm

 

Sounds like distributer to me. Try swapping it for a known good one. Also what code is it throwing?

 

Did you try pulling the code(s) from the MIL? Yes, it does sound like it's going into limp/home mode, which seems like it's a MAP sensor trouble code.

 

The MAP and TPS connections are the same and can easily be switched. This causes the car to run like crap and would send it into limp mode. What code is it throwing?

 

We tried that and we had it on the right way before (car started jerking around after we switched it). I forgot what codes it threw but I'll find out, both codes were IACV or intake related.

 

I need help guys! I tried switching to GS-R IACV today and it still had very rough start but didn't die, but it wasn't completely cold either I only had it off for about 3 hours.

We also tried manually operating VTEC by hooking up some wires and sticking the wire into the cigarette lighter but we did not feel it engage at all.

 

Vtec needs 3 things to engage. Temp, Oil Pressure, and Electricity. One of those is missing.Best thing you can do is find out what codes you are throwing so people can give you better ideas. also see if the ecu has been messed with.

 

its most likely the ecu...get a p72..cuz the p73 come in the ls and ls=no vtec

 

p73 = itr
p72= gsr
p75= ls

 

um yea p73 is a ITR head! and keep in mind that you may not feel it as much as you did with your old gs-r motor because on your old manifold you had the secondaries and now you don't, so if your looking for that give up. but if its a loss of power, from my experience and like these other guys have already said, distributor! cause distributors are from hell, ha

 

+1

 

lol opps my bad for the wrong info

 

I'm having that idle problem at 1500rpm when its at normal temp. I believe this is because of the stock gsr mani not being there anymore and running a stock ecu. You need to run obd1 for that.

What codes are you throwing now?

 

I hope you guys are right about the difference in intake manifolds. When I had the GS-R motor in and I took the airbox cover off the crossover was very loud. With the ITR motor I took the airbox cover off and I do hear a numb increase in volume by a tiny bit.

The cold start problem is my biggest concern however. The car has not thrown a code in 2 days after switching to the GS-R IACV. I'm running on the ITR ECU right now.