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jrsc b18c problems

Posted: Mon Apr 28, 2008 8:10 pm
by goreycop
I am having problems with my jrsc "high boost" setup on my b18c Civic. It is the jdm gsr motor, and I am running a p28 ecu that you guys socketed and installed s300 on. I am running RC 440cc injectors. The car has always had a rich and stumbling idle. When driving the car at part throttle (constant speed), the engine feels like it has an on-off switch. Either I am decelerating or accelerating.

The datalogging file I sent is the car idling. One thing to note is that I have to have the IACV duty cycle at 75%. If it is lower than 50% the car just stalls. From 1:05 to 1:30 in the log file I am trying to hold the car at a constant 2500 rpm's or so. As you can see, the revs raise and drop from idle irratically even though the tps angle is nearly constant.

At 2:04 in the log file it looks like the s300 stopped logging even though the car kept running the same. Strange.

The car has a brand new distributor, and a brand new tps. I tried to set the base timing as best I could with the rough idle. I have a walbro 190 lph fuel pump and a stock reg.

Any ideas I am stumped?

Posted: Tue Apr 29, 2008 10:14 am
by Spunkster
Has it been tuned on the dyno yet? If it has not yet been tuned, then that should be yoru first step. I believe this engine has higher compression than the US B18C1 which is what this was tuned on. It will be impossible to adjust your A/F properly without a wideband.

Posted: Tue Apr 29, 2008 10:38 am
by goreycop
I havn't had it on a dyno yet. I do have an afr guage and when the car is making boost I am seeing a 11.5:1 afr. Whenever the car isn't under boost, its running rich as hell (like 8:1, the low end of the scale). Would the little extra compression from the jdm engine cause everything to be so off at idle?

Posted: Tue Apr 29, 2008 11:08 am
by Spunkster
If it is running that rich, then you need to get it on the dyno and get it tuned as soon as possible. Running that rich will wash down the bores and cause ring damage.