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View Full Version : SR20 Trouble Shooting, WTF L


Sileighty_85
08-07-2007, 12:32 PM
Okay so my buddy picked up a an S13 Hatch with an SR Swap Wouldn’t run for it life.
Dumped shit tons of fuel, (but kinda cool if you wanna make your car Shoot flames) lol But first off looking it over the fuel lines were backwards fixed it and started but ran rich as hell, I traced it down to the MAF, (Wrong MAF) I unplugged it and it ran better still rich and in safe mode so it wont REV over 2,500. Threw on a known working MAF, will REV freely but still runs rich.

Now it gets weirder, It runs little rich, idles good for a while but when Rev’ed I guessing when gets hotter #1 Cylinder Shits itself Starts running Rich as hell again, and starts stumbling I’ll pull the Coil pack or Fuel injector with no change in idle on #1 (while running crappy) Its definitely getting fuel and its still getting spark. If pulled on any other cylinder change is noticed.

ECU throws Code 55 (No Malfunction)
REPLACED COOLANT TEMP SENSOR (used SR20DE from 93 Sentra) and thermostat (KA)

Swapped Igniter Chip, CAS, Swapped ECU’s from My Running SR , Swapped Wire harness and ECU from Buddies other Chuki Black Top SR, Fuel Rail, Coil packs with harness, and I rebuilt the Blown Turbo. Only Idles better, #1 Cylinder still do-do’s itself.
(Original ECU and Wire Harness is Back in the Car.)

Mechanical Timing is fine, CAS has been Set to correct Timing
Compression Test Shows 155-160 Across all Cylinders when hot WOT
150ish WOT when Cold holds compression with no change.

Ive been suspecting it’s the Wire Harness since we got it, it looks nice but I don’t trust other ppls wiring when it comes to Engine Wiring. (unless professionally done)
But it confuses me cuz when we swapped his Chuki Harness and ECU it still did the same thing. But it was before most things replaced. (He said His Black Top SR was acting up also)
So Im thinking Maybe it’s a common Miswire ppl are doing when they personally wire it them selves?

But I was working on it yesterday performing the “Wiggle Test” On the wire harness So im sitting in the driver seat and I lean over to grab the ECU and it started Shocking me, So it seems there is a short.
When I turned the ECU upside down, messed with the Main harness for the ECU or grounding the ECU to the Chassis it began to act up. So I’m pretty much convinced it the Wiring So we are gonna send it off to Yury @ Wiring Specialties.
Also I noticed a few cut wires in the Blue ECU Plug about 4 or 5 of them.

Its Stock R/T Engine
Supporting Mods is FMIC and SSQ BOV, Greddy Boost Controller and Apexi Turbo Timer

Just wanted a second opinion.

Thanks

!Zar!
08-07-2007, 02:24 PM
Are you sure the front mount piping is air tight?

Because if you have an air leak than you could be running rich due to un-metered air entering the system.

aa87
08-07-2007, 03:32 PM
We figured it out, the frickin case for the ecu was pretty banged up and was making contact with the board, swapped the case, runs great-town. Thank god i didnt fry that shit.