HELP , misfire issue r32 gtr

[bakerman1978]

SKym you know so much about our cars that's awsome I'm curious though which of these would cause the same cylinder to fail everytime because I swapped the coil packs and the same cylinder failed as before and it is only when the car had been drivin for a while and the misfire is through pretty much the whole rpm range and the smell of fuel is very noticeable once it starts missing so would the 02 sensor cause a misfire while driving or just at idle,I'm thinking it's the coilpack or injector loom just because the plastic and wires are so old that it may give out under high heat

What can cause missing -

Coilpacks (coilpacks are damaged due to wide sparkplug gap, incorrect heatrange and engine can randomly run on 5 cylinders and then eventually always run on 5 cylinders, usually 2x coilpacks fail and rest are ok, but best to replace all 6 coilpacks if sparkplugs weren't gapped down and engine missed at higher rpm)

Coilpack loom (due to age and if stiff as a ironing board, replace it)

Ignition module (engine would stall after 10 minutes of driving and won't be able to start it for another 10 minutes due to ignition module has to cool down). But can cause some cylinders to not fire (rare but does happen).

Injector loom (due to age and if stiff as a ironing board, replace it)

CAS (bearings inside fail due to age, engine hard to start when cold, hot, eventually engine starts randomly stalling, rough idle), Sometimes incorrectly set CAS can cause missing.

Also Skylines can missfire at idle due to o2 sensor making engine go lean (lean missfire). If unplug o2 sensor x2, start engine it should idle smooth. If this is the problem, then ECU retune is needed to correct this. This is a common problem on many modified Skylines with retuning ECU.

MAF's can make ECU make engine stutter if there's a intake airleak just after MAF'S (similar to coilpack failure and often can be mistaken for coilpack failure).

Intake leak before MAF can make MAF max out and hit boost cut (fuel cut) on ECU (if have clamp onto adaptor type of airfilters infront of MAF's. Fit Apexi or similar podfilters that bolt onto MAF's to fix this problem).

Injectors can start leaking, which makes engine seem like it's misfiring.

Intake manifold gasket's can blow (common on GTS, GTR) which can make rpm go up and down (due to o2 sensor making ECU make engine go lean, rich) causing a rough idle. Engine running leaner, into 17's should give it away.

Too thick oil for engine, which makes engine struggle to idle, sluggish response, etc.

[hp44incgtr]

yeah i just swapped my coils and it's still cylinder 4 that goes out so I'm wondering if the injector or injector wiring could fail under high heat but I think I might clean my mafs next and see if that makes a difference ahh the joys of being a skyline owner it always gives you something to do
Quote Orig


buddy its like i told you its an connection problem the reason why the car runs good when its cold is because the contact is being made but soon as it warms up the contact is not has good its an shitty connection thrust me change those wires or atleast open up the loom take an look at them and dont just look feel them cause sometime the insulation looks found but the wire it self is rotten inside..

[Skym]

SKym you know so much about our cars that's awsome I'm curious though which of these would cause the same cylinder to fail everytime because I swapped the coil packs and the same cylinder failed as before and it is only when the car had been drivin for a while and the misfire is through pretty much the whole rpm range and the smell of fuel is very noticeable once it starts missing so would the 02 sensor cause a misfire while driving or just at idle,I'm thinking it's the coilpack or injector loom just because the plastic and wires are so old that it may give out under high heat

It's just some things I have picked up from my cars, others cars part failures.

When o2 sensor fails it's slow to respond to sudden changes in A/F ratio, so o2 sensor makes ECU make engine stay rich longer and pops flames from exhaust (without cat). It doesn't make engine missfire (you can hear a popping sound from exhaust).

If it's coilpack related (leaking charge onto mounting bracket), should have grey marks under mounting bracket on both sides of coilpack (sparkplug tip where coilpack has failed will be black if running on 5 cylinders). If leaking injector, injector loom problem, ignition module failure, should running too rich on one cylinder, usually sparkplug tip will be black.

If replace coilpacks, ignition module, coilpack loom and problem is still there, I would think injector problem (leaking) or injector loom problem (common problem when engine ages). In some rare cases loom from ECU to engine can be damaged.

When coilpacks failed on my car it was on cylinders 4 and 5 and I asked Nissan and they said they find it's common for 2x coilpacks to fail and was due to incorrect sparkplugs with heat range or sparkplug gap (what I had found out the hard way, but was sparkplug gap, wrong heat range related on my car). If heat range is wrong, sparkplug tip can foul or burn the tip thus making gaps wider.

Also I have heard of a stock ECU making one cylinder stay lean (cylinder 1 on a RB20DET), from memory caused ring failure on that cylinder. I assume injector drivers on ECU had failed. So try swapping engine ECU and see if that fixes the problem.

Someone else had a similar type of problem on here (high idle) and was ECU related (ECU was modified, so might have been static damage). Swapped ECU, problem solved.

In some cases the ECU loom plug is not seated into ECU properly (putting ECU loom plug in on angle and bolting it down) causing engine to miss or not run properly.

[hp44incgtr]

If replace coilpacks, ignition module, coilpack loom and problem is still there, I would think injector problem or injector loom problem (common problem when engine ages). In some rare cases loom from ECU to engine can be damaged.


problem def there well from my experience thats where i found my missfiring problems think about it people how old are this cars how old are this wires that sit in constant heat hot and cold heat kills wires they get rotten..

[Skym]

Should see my cars coilpack loom, stiff as a ironing board (can't bend it. If you do bend coilpack loom, could break it). That was due to alot of heat.

I noticed in Japan when rebuilding engines on R31, R32, etc they replace all of the engine bay looms (including main loom).

Some redo and make the wiring better, as sometimes the wiring can fall out of the plugs if wiring is pulled on instead of plug (common problem with Nissan's). Some put a bit of tape, shrink wrap or similar around wiring (gives plug something to grip onto) which helps to prevent wires from slipping out of plug.

[hp44incgtr]

Should see my cars coilpack loom, stiff as a ironing board (can't bend it. If you do bend coilpack loom, could break it). That was due to alot of heat.

I noticed in Japan when rebuilding engines on R31, R32, etc they replace all of the engine bay looms (including main loom).

Some redo and make the wiring better, as sometimes the wiring can fall out of the plugs if wiring is pulled on instead of plug (common problem with Nissan's). Some put a bit of tape, shrink wrap or similar around wiring (gives plug something to grip onto) which helps to prevent wires from slipping out of plug.

Like

RESPONSE MONSTER


would def replace them this is the second time im replacing mine first time an use one that was decent now im in contact with daryl at right drive trying to get an new one but his out of stock only one he has in stock is the oem one at an killer price so im gonna wait for the after market one..

[Skym]

It's not cheap. One thing I found interesting about new coilpack loom is the stickers with cylinder numbers on them fell off into around sparkplug area (heat breaks down the glue that holds them on). I would remove the stickers with cylinder numbers before installing coilpack loom.

[bakerman1978]

would def replace them this is the second time im replacing mine first time an use one that was decent now im in contact with daryl at right drive trying to get an new one but his out of stock only one he has in stock is the oem one at an killer price so im gonna wait for the after market one..

yeah hp44incgtr I called daryl to for the same thing, and said next wednesday or thurday they'll be in so I will probably start with that unless I can track down the other guy with a gtr in my town and swap the ignitor and coilpack loom to narrow it down

[bakerman1978]

It's just some things I have picked up from my cars, others cars part failures.

When o2 sensor fails it's slow to respond to sudden changes in A/F ratio, so o2 sensor makes ECU make engine stay rich longer and pops flames from exhaust (without cat). It doesn't make engine missfire (you can hear a popping sound from exhaust).

If it's coilpack related (leaking charge onto mounting bracket), should have grey marks under mounting bracket on both sides of coilpack (sparkplug tip where coilpack has failed will be black if running on 5 cylinders). If leaking injector, injector loom problem, ignition module failure, should running too rich on one cylinder, usually sparkplug tip will be black.

If replace coilpacks, ignition module, coilpack loom and problem is still there, I would think injector problem (leaking) or injector loom problem (common problem when engine ages). In some rare cases loom from ECU to engine can be damaged.

When coilpacks failed on my car it was on cylinders 4 and 5 and I asked Nissan and they said they find it's common for 2x coilpacks to fail and was due to incorrect sparkplugs with heat range or sparkplug gap (what I had found out the hard way, but was sparkplug gap, wrong heat range related on my car). If heat range is wrong, sparkplug tip can foul or burn the tip thus making gaps wider.

Also I have heard of a stock ECU making one cylinder stay lean (cylinder 1 on a RB20DET), from memory caused ring failure on that cylinder. I assume injector drivers on ECU had failed. So try swapping engine ECU and see if that fixes the problem.

Someone else had a similar type of problem on here (high idle) and was ECU related (ECU was modified, so might have been static damage). Swapped ECU, problem solved.

In some cases the ECU loom plug is not seated into ECU properly (putting ECU loom plug in on angle and bolting it down) causing engine to miss or not run properly.

thanks again for the detailed info skym

[Nvdgtr]

update from mine:

-I cleaned the maf and checked that nothing was broken.
-Paul (cortex) came by and dropped off a set of coil packs for me to try.
-I also checked all my injectors and changed a few cracked o rings so that might help.

tomorrow I will put the car back together and take it for a spin, and hope i have fixed it. if not paul said we can try his igniter and or maf. if that doesnt fix it ill continue on the search..



Id take a bright flash light and shine it on ur injectors/fuel rail, have the key turned on so the fuel pump is on and see if you can see any wet areas (gas leaking out) or theres a top rubber ring sometimes these crack and you can probably see them with out actually removing them. though there are 2 other o-rings that might have issues. to check this you have to remove fuel rail, be careful with clips they can break easy.

[bakerman1978]

thanks I replaced my injectors last year with used ones (silver and yellow) so all my orings are new but let me know how it goes with the ignitor and or mafs

update from mine:

-I cleaned the maf and checked that nothing was broken.
-Paul (cortex) came by and dropped off a set of coil packs for me to try.
-I also checked all my injectors and changed a few cracked o rings so that might help.

tomorrow I will put the car back together and take it for a spin, and hope i have fixed it. if not paul said we can try his igniter and or maf. if that doesnt fix it ill continue on the search..



Id take a bright flash light and shine it on ur injectors/fuel rail, have the key turned on so the fuel pump is on and see if you can see any wet areas (gas leaking out) or theres a top rubber ring sometimes these crack and you can probably see them with out actually removing them. though there are 2 other o-rings that might have issues. to check this you have to remove fuel rail, be careful with clips they can break easy.

[bakerman1978]

If anyone wants to know the problem is fixed it was the ignitor thanks

[93VSpec]

Just going to chime in that I'm having a very similar problem.
I don't think it's my coil pack or loom though, as I'm getting a very lean count on my wideband when it starts to misfire. Makes me think it's the injector loom or an injector.
Does anyone have a good idea on how to check an injector loom without buying one and swapping it?

[93VSpec]

I had some bad connectors on my coil pack loom, so I've changed that out without helping the cause.
Anyone have ideas on how to check an injector loom? Or does anyone in SW ontario have a spare one I could borrow to test?