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Projek01
08-26-2015, 10:55 AM
Hello,

I am looking for help with my cylinder 2 misfire that has been bugging me for a few years. The car needs a clutch/main seal soon so I thought id tackle everything at once. Engine has ~250k km on it but it has fairly good compression numbers on it so I don't want to rebuild it.

It is a 5SFE with distributor and single coil. Ignition timing is not adjustable (I believe it is controlled by the ECU)

Things I have tried:
Spark plugs
Spark wires
Distributor cap and rotor
New PCV valve
Cleaned EGR valve, passages and vac hoses
Swapped coil packs with another car
Swapped injectors around
Compression test (185psi +/- 5 psi for all 4 cyl)
Seafoam

Cyl 2 used to have a leaky valve stem seal that has been fixed. I am guessing there could be more crud in this cyl. Would this be something that the compression test would pick up?

Fuel trims look normal. Misfire and stumbling is rather intermittent. Some days it will noticeably shake and some days it drives very nice.

Any pointers would be great! Thanks.

ae92gts
08-26-2015, 11:14 AM
I had this same problem on my 1992 Toyota Celica with the 5SFE. I actually blew my timing belt (non interference engines FTW). after I retimed and replaced my timing belt I had a intermittent misfire. I changed the ignition coil (the one inside the dizzy) and the ignition box thingy attached to the drivers side firewall (forgot what its called). Between those 2 parts the problem seemed to disappear.

By what you've said you changed the ignition coil inside the dizzy? try the ignition box thingy on the top drivers side firewall (ill try to find the right name for it) and if I remember correctly I could only find the "thingy" from Toyota.

EDIT: "thingy" = ignition module :banghead:

Projek01
08-31-2015, 12:37 PM
Hmm thanks. I actually swapped ignitors and external coils from another celica at PnP. Behaviour and cylinder 2 misfire never changed actually. I wonder if there is anything inside the dizzy that could go bad. I am almost stumped at this point.

RickDaTuner
08-31-2015, 12:45 PM
You more than likely have a bad terminal pin, or wiring in the #2 injector. I would just splice in
a repair pigtail connector, and see if that changes things.

Given all the work you have performed, there is really only a few options left.

1. More faulty wiring.
2. PCM related internal driver fault.


Wiring is that last thing most people look for in miss fires. I once had a guy that had swapped out an entire engine due to a broken pin in the coil driver harness... :dunno:

Kloubek
08-31-2015, 12:52 PM
Originally posted by RickDaTuner
You more than likely have a bad terminal pin, or wiring in the #2 injector. I would just splice in
a repair pigtail connector, and see if that changes things.

Given all the work you have performed, there is really only a few options left.

1. More faulty wiring.
2. PCM related internal driver fault.



This is exactly what I was going to say. Looks like everything else has been covered off. Either wiring to the injector, or the PCM. Should be able to test for resistance without too much trouble between the injector plug and the PCM, ruling that out.

I actually had a similar issue with a TJ I bought. Ruled everything out, and only thing left was the PCM. Got a rebuilt one and the thing ran like a champ. (Until the cat plugged up immediately after)

Projek01
09-01-2015, 01:58 PM
thanks for the tips guys! I will take a look at the wiring and pigtails.