Where to Start with Single Cylinder Mis-Fire?

[Ramius83]

Ok guys and gals. I have been working on a friend's RHD converted SR20DET S14 for the past couple of months now. I have done a LOT of patch work on this thing that the shop who did the RHD phucked up badly. this includes re-wiring some parts of engine bay, cleaning up wires, battery relocation, better intercooler piping, blah blah blah. Even with me driving it after doing all of this I discovered that the head gasket was leaking, causing the engine to overheat and constant bubbling out of the coolant bottle. And this has supposedly been and on-going problem for this car. So I threw in a Tomei headgasket and ARP studs to remedy this problem as well. And now it drives fine with no coolant leakage into the cylinders and now overheating problems.

Anyways, to my point. Cylinder 1 has a constant mis-fire that comes and goes, especially at IDLE. I have tried switching Coil Packs with the other good cylinders, this did NOT fix the problem. I have tried switching the fuel injectors, this did NOT fix the problem. Timing is dead on at I think 15 degrees if I remember correctly and the appropriate sensors, ie MAF, TPS, CAS, ECT, all appear to be good with the use of Consult.

Now, is this a "common" or "heard-of" problem with the SR20s? I am an RB dude personally, as I drive an RB26 swapped S14, but I am just wondering if this does happen or has happened with any of your swaps.

Within this week, I am going to be looking into the wiring job. I am thinking of running a direct wire from the Cylinder 1 Coil-pack wire at the ECU, directly to the Ignitor, and then another wire from the Ignitor to the actual coil-pack itself. I think that this will help me rule out wiring issues. But, and but, if this doesn't work, what else could it be? Thanks all for your input......

[xsublimefrekx]

if you could find an ecu i would try that first before rewiring things. Im not sure if that willl help any but its just another step that can be taken before rewiring things.

[burntricer]

check your ignitor

[Hijacker]

ignitors rarely let a cylinder occassionally mis. when an ignitor goes down, it goes down. no in between.

I would consider running a compression test on that cylinder. If the misfire is not following the injectors or the coilpack/spark plug, i would start ruling out mechanical failure.

Before you consider running a direct wire, just double check to make sure that there isn't an exposed wire somewhere. If the shop was as bad as it sounds, it's possible they frayed the wire shielding somewhere for that coil pack and it just needs to be fixed. Trace it all the way from the ECU through the EFI harness, to the ignitor, and then to the subharness for the coil packs. A lot of times, wires get rubbed on the firewall during installation or removal. I've sliced my fair share on accident.