Shakes or Wobbles problem
1992 Nissan 240SX 4 cyl Two Wheel Drive Manual 170000 miles
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background: i dd a 92 240sx with the original ka. bought it with 104k miles now it has 173k miles. Earlier this year, i noticed that SOMETIMES my car had a trouble starting up. It misfires/sluggish the first 3 seconds of startup and then idles normally (~800rpm) and the engine check light appeared. I thought i might be leaking fuel so i decided that i was going to replace the o-rings on the fuel injectors. Never got to replacing it because of the busy school schedule. The car runs perfectly and i noticed that this problem only appears during cold start.

After coming from a 5 day vacation last month, i started my car and the misfiring was still present and i figured to check which cylinder was out. The problem appeared to be on cylinder 3 where there were no changes in the rough idle after i pulled the #3 plug wires.

I checked the ecu and came out to be code 35 (weird) which was the code for the egr i believe..(but how would the egr affect the #3 cylinder?). I cleaned the egr and reset the ecu but the problem was still present.

This time, i check if my injectors were functioning correctly. Again, #3 injector was out so i replaced it with a rebuilt injector. Started up the car again, and cylinder 3 was still out...I then tried to check for compression on all cylinders and got 180,185,180,180. I dont understand what is happening and is frustrating me.

I replaced numerous parts already (new plug wires, new oem spark plugs, rebuilt distributor cap)and i am still getting a dead #3 cylinder.






cliff notes:
misfires on #3 cylinder
checked fuel injector: #3 was bad. removed and replaced, now all injectors work fine
checked compression: ~180 across the board
replaced plug, wires, cap





UPDATE:
i tried another compression tester (from autozon) to see if maybe the one that i used (borrowed from my friend) might be off. i got the following results

#1: 165
#2: 170
#3: 165
#4: 165

that takes care of the compression problem. But as I was removing the spark plug. i noticed the the #3 plug (the cylinder that was misfiring) hasn't even gone off yet. What i mean by that is i do not see any signs of the plug firing.

what else could be wrong? i put new oem plugs, Brand new plug wires, new cap, and i also recently swapped the ecu from a different running car.




update 082808:
i did the noid light test last night on all four. it lights up, so im assuming the harness works...i tried swapping the injector harness (i put #4 to #3) to maybe verify if the harness works and #3 is still dead.

I bought new distributor rotor since they only cost $10...#3 still dead

i tried swapping plug wires to check maybe the one that i got is defective..still dead
i tried swapping plugs, #3 still dead


could a bad distributor cause only 1 cylinder to misfire?
since i am getting good, consistent compression on all 4 cylinders, could a valve be stuck? intake valve stuck (not getting air=no combustion but holds compression?)?
sensor problem? --> if it is, but why only one cylinder consistently?

Wow, I have the exact same problem.

1991 240sx, Number 3 Cylinder is dead on a 160K engine.

Last year, replaced rotor, distributor cap, wires, fuel filter and the problem went away.

This week, symptoms reappeared.

It seems to happen during summer/fall season change for my car (wisconsin).

Sometimes, a fresh gas tank plus some fuel/injector cleaner helped.

Let me know if you find a solution