s13 sr20det randomly started misfiring.

[tunersedge]

Let me begin by stating that i have been having this issue for almost 3 weeks. I have scoured the internet for answers and i havent found anyone with a similar problem...Ill try and supply as much pertinent info as i can.
Motor is a s13 sr20det in a s14.
I was driving my car around one 2 weeks and out of no where it just started to misfire, and fire only on cylinders 2,3, and 4. No matter what RPM im at, it still misfires constantly on cylinder #1. I pulled the ECU codes and im throwing, 13(Engine Coolant), 21(ignition signal) and 34(knock sensor).
I replaced the ECT sensor and Power transistor unit(ignitor) and that didnt resolve the misfire.
Misfire is constant whether engine is hot or cold.
The injectors are ALL good.
Im getting spark to all 4 cylinders.

The thing that puzzles me is how it just started to misfire out of the blue while i was driving around.
Could my camshaft position sensor cause a misfire such as this?
(tho i dont know how it would get thrown off)

[Team DET]

i was going to say check spark plugs to see if they are loose..... my misfired and it came out to be the spark plugs where loose by 2 full turns the two closes to the front

[nismown3d]

my guess is bad coilpacks or ignitor chip. mine started doing that last year, i retarded the timing and it ran a bit better until i bought spitfires.

there are tons of stuff you can try. try swapping your ecu, swap with coilpacks that you know work.

[warpd]

Coil pack would be my guess. It's only misfiring on one cylinder correct? If so that would rule out cam or crank sensors because then you would have random cylinder misfires across all cylinders. The coil could be putting out spark visibly but under load not functioning well enough to ignite the mixture thus causing a miss. The knock sensor code could be a result of this.

[njd07]

always check the ecu to harness connection. I had a misfire before and so did a friend just becuz the ecu/harness connecters wire not perfectly straight. so take off the connector and carefully recconnect.

[fbiphil]

Start with new plugs- Sr's seem to be hard on them, and they're super easy to replace.
I bought new coilpacks thinking that was the problem, and it turned out to just be the plugs... always good to have spare parts, right?