98ek jdm gsr please help!

We may earn a small commission from affiliate links and paid advertisements. Terms


New Member
Hi everyone, I am new to the hondaswap fourms and Im wondering if you guys can help me out. I have 96 jdm B18C in a 98 civic ex/ek. Motor is stock and I have the basic bolt on right now. CAI, EM, CATBACK,NO CAT/TESTPIPE. also used the wiring harness from the stock d16y8 with some slight mods. Using JDM p72 ecm

My problem is my idle is random and seems to be higher the colder it gets

When i come to a complete stop it always drops bout 500 give or take.

Its Idling anywhere from 1500 to 2500 when going 20 in netrual

If car isfully warmed up the idle is normal when still but sill high when going 20 in netraul.

If car is fully warmed up the idle will somtimes surge very hard from 1500 to almost stalling and will stall sometimes(very annoying). This is normally going 20 in netrual.

Things ive done to try and fix this problem

Clean IACV

Timed to a T

Smoked intake for vac leaks(none)

New TPS(old one was bad)

Other Questions that could help me fix this problem

Do JDM b18c(1996) have a fast thermo valve?(cant seem to find mine) (looked under TB) (maybe not good enough)

Also had to wire the black box under intake(Forgot the name)(for butterfly intake)Im getting 12v from the sensor with key on/engine off. Is that correct?

Thanks for any input. please dont bash me if i didnt post this correctly for im am new to the froums.(first post ever for any fourm) also new to the honda world as this is my first swap. Again thanks for any input
The black box is the secondary intake runners, they kick in around 5,200 RPMs give or take lol. As for your strange idle, have you checked your dizzy cap and rotor? The coolant sensor could also cause this strange idle, just some ideas
Thanks for the input. I will check them tonight. Could you explain on how the dizzy might affect this. I know my ign. timing is good. what else might i look for in the dizzy
you could remove the cap, and check for corrosion on the terminals and the rotor it self. if they have some build up a simple dremel with a steel wheel on them takes it off, or some sand paper. Just and idea, if this improves it then ya mite want to spend $40 or so and replace the cap and rotor simple fix :)
Post pics of your engine specially around the intake area.

Many swaps issue I've seen ask.

I'm not sure about the FITV on the Jdm gsr, but my JDM b16 has them right under the TB.

The FITV does its job when cold, when warm its mostly the IACV.

Did you somehow switch the TPS connector to Map sensor connector?

Check your trottle cable adjustment.