s13 rb20det will crank, wont start, will pop start... help!!

[tetsuo41]

sooo ive had this car over a year now and all of a sudden, im at the gas station, finish pumping, then go to start the car and it wont start? the starter cranks, but won't start. i ended up having my buddy push me and i pop started it... got home after all this, shut it off, and tried to start it up again, and it did the same thing, would crank but would not turn over. im a little confused as to what it could be, i drove home about 40 mins to an hour with no problems, idled fine, revved fine. only new modifications are a beefy radiator, and a set of yellow jacket coilpacks. has driven/started fine since i put those in like 4/5 days ago. never had any problems starting it before even when it had junk stock coilpacks in it sputtering in wot... i was thinking maybe fuel pump but then why would it drive fine after i pop started it? thought maybe i got s*** gas, might have had some water in it, but again drove fine on the way home and i only ever put 93 in it.. really confused and in desperate need of help, where are the rb gurus at? lol

battery connection is good, didnt find any blown fuses, wiggled all the wires that were reachable..... we just got a ton of snow here in pa thought maybe i sucked up a lil water or something, but it ran fine once i pop started it.... ???? lol im lost

its a silvertop rb20det, in a 1990 s13 coupe
only aftermarket stuff installed maybe to help diagnose my problem are intake, exhaust, thicker radiator, yellow jacket coilpacks, ebc, vlsd w/nismo gears in the rear, fmic, 6 puck clutch and lightweight flywheel... most of that wouldnt make any differance but there ya go..

thanks in advance

[compactfean]

Well I'm not an RB guru but a Nissan guru in general. I've had the same problem on my SR and Nissan ecu's. Pretty much all work the same. When I first did my motor swap I had my start signal wire hooked up but still wouldn't start on its own I checked fuses and all were good. I directly wired the start signal wire to starter wire and problem solved. Well when I built my motor and tried getting everything running it wouldn't start. Checked continuity from starter wire to the end of the harness and it was good. Ended up being the ecu pin solder came loose. If your wiring is done right I would just start with checking. Start signal fuse. If it has no power coming in or out than you will have to dig further. (Must be tested when cranking)

[tetsuo41]

i forgot i made a thread about this, i was sleep deprived from shoveling and plowing this last snow storm we got in pa. but i woke up the next day and it started fine, drove around for a bit, killed it, tried to start it again right away and it wouldnt. so after a couple days now ive figured out it will start after the motor cools off a little bit, dosnt have to cool off completely, just less than running temperature. has me a little stumped. but thanks for the advice i will be pulling some things apart and seeing what i can find.