TSuaVe
04-18-2007, 04:34 PM
I've got a '95 240SX with a S13 Redtop swapped in. Full turbo back 3inch w/ test pipe. Greddy fmic. S14 T28 turbo (freebie) Walbro 255 fuel pump. Koyo Radiator. Original injectors, and fuel pressure regulator. Tech Edge wideband with narrowband output wired to ECU. Ok, now that the specs are out of the way...
Problem #1:
The car idles pretty good until it reaches operating temp. Cold it idles about 1500 rpm (normal) and then comes down to about 1100 at operating temp. Then as things start to heat up, the idle drops to 800-850 (ideal) but has a horrible stumble and my wideband reads way lean anywhere from 17-19 A/F. This all happens while my temp gauge is reading normal temps and cooling fans (on external controller) are cycling normally. My first thought was sticking fuel pressure regulator because I could bump the throttle and it would go back to running normal AFRs at 1100 rpm. Before I got my wideband hooked up I didn't know details of the low idle condition and figured it was normal (except for the mild stumble). I let the happen again after the wideband was hooked up and after a minute or two of idling at the is lower/leaner rpm, I start getting white smoke from the exhaust. Oil smoke. I associate that to the lean condition. (correct me if I'm wrong...)
Problem #2:
I was getting an excessive heat issue cruising on the highway and at idle AFTER temps rise slightly above 175-180F. I figured the thermostat was sticking a little bit and replaced it. No more idle heat up issues but I still have the highway heat up issues above 70mph. I can turn on the heater and it brings the temps back down. My understanding is that the fans should not have to run at highway speeds. Correct me if I'm wrong.
I'm not sure if these two problems are related, but I wanted to get some insight from more experienced S20 owners before I just start throwing parts at this thing.
Problem #1:
The car idles pretty good until it reaches operating temp. Cold it idles about 1500 rpm (normal) and then comes down to about 1100 at operating temp. Then as things start to heat up, the idle drops to 800-850 (ideal) but has a horrible stumble and my wideband reads way lean anywhere from 17-19 A/F. This all happens while my temp gauge is reading normal temps and cooling fans (on external controller) are cycling normally. My first thought was sticking fuel pressure regulator because I could bump the throttle and it would go back to running normal AFRs at 1100 rpm. Before I got my wideband hooked up I didn't know details of the low idle condition and figured it was normal (except for the mild stumble). I let the happen again after the wideband was hooked up and after a minute or two of idling at the is lower/leaner rpm, I start getting white smoke from the exhaust. Oil smoke. I associate that to the lean condition. (correct me if I'm wrong...)
Problem #2:
I was getting an excessive heat issue cruising on the highway and at idle AFTER temps rise slightly above 175-180F. I figured the thermostat was sticking a little bit and replaced it. No more idle heat up issues but I still have the highway heat up issues above 70mph. I can turn on the heater and it brings the temps back down. My understanding is that the fans should not have to run at highway speeds. Correct me if I'm wrong.
I'm not sure if these two problems are related, but I wanted to get some insight from more experienced S20 owners before I just start throwing parts at this thing.