Unhealthy '32

[Rowdy]

G'day guys-

so i bought a '92 R32 gtst with a t3/4 hybrid, FMIC, and exhaust, and the sixth cylinder isnt firing at idle, and it sounds like its detonating at high revs.

i picked it up cheap, so i figured the problems where warranted.

i was hoping i could get some help diagnosing the problem?

ive tried a few suggestions, and have swapped coils, plugs and injectors, even igniter pack and coil loom. compression test came up with 127 on no.6 better than the 125 on no.1! ive run the plug on the manifold and there is spark visible. I can hear the injector actuating.

other cylinders are running fine. theres no black smoke from the exhaust.

not sure if its related, but the tacho can sometimes fluctuate wildly, reading 6,000rpm when im only doing about 3, and then gets stuck for a while, before returning to normal. (possible earth fault?)

any help from the resident skyline guru's would be much appreciated.

cheers guys!

Rowdy.

[Grunter]

Mate I would suspect the injector it self maybe? You have eliminated everything else

so far,quite possible that it's not spraying correctly.Also go to a mechanic and get them

to check that there is power down to the injector it self they pull the plug off and stick

in a little light which 1 shows there is power and 2 that it pulses.Some times when there

is dirt around the spark plug holes they can short and track the spark.Another thing to

to try is spray electrical cleaner on all the loom conectors.Maybe this might help a few

more things to try good luck.

[Rowdy]

Mate I would suspect the injector it self maybe? You have eliminated everything else

so far,quite possible that it's not spraying correctly.Also go to a mechanic and get them

to check that there is power down to the injector it self they pull the plug off and stick

in a little light which 1 shows there is power and 2 that it pulses.Some times when there

is dirt around the spark plug holes they can short and track the spark.Another thing to

to try is spray electrical cleaner on all the loom conectors.Maybe this might help a few

more things to try good luck.

thanks mate, ive tried swapping the injectors around and i can hear it actuating, and have stuck a multimeter over it... and the heads as clean as a whistle. will use salubrious amounts of electrical contact cleaner though

cheers

common guys, someone must know?

[tacker]

have you check valve clearence check the exhaust valves on # 6

[nizmonut]

swap the spark plug with number 2 or 5 i had issues with water getting down ontop of the engine near the fire wall, i have no idea how.

when you pull the spark plug out if there are burn marks or a white crystal type powder building up around the middle of the spark plug id say the creamic has got hair line cracks and is earthing out to the head before the current gets to the electrode,

the reason i say 2 or 5 is because if you swap a dud spark plug with 3, 4, or 1 the miss sequence wont change, where as swapping it with 5 you will notice immediatley the change in the way the engine idles.

if the spark plug fires fine on 5 you have a dud coil pack, if its missing on 5 the sparkplug is buggered.

dont have to go anything special, 5 dollar NGK's with a .8 ml gap is fine.

gapping the plugs to .8 is a easy fix for weak firing coil packs that are deteriating, this is a sign that the igniter pack is failing aswell, this can be replaced with an ignitor from Triton for a v6 maxima or 2.5 v6 cefiro which are half the price of the rb igniter packs.

how ever it is advised to get new coils aswell or change to a wasted spark ignition system.

Edited July 29, 2008 by nizmonut