Misfire Problem

[sxygirl]

Hi there, this is my first post here, and firstly Hello - i actually live in Scotland and have an r32 gtst 4 door as well as an r33 gtst which i havent had for long. I am having problems pinning down the cause of a misfire problem. So far i have changed the spark plugs , changed the coilpacks (installed a wasted kit), just installed a walbro fuel pump. Took it out the other night - car still misfiring but showing 2.6 bar of fuel pressure on idle, up to 4 bar under pressure - it drives through the misfire and does run smoothly, as it does on idle, it only gets rough under pressure. Does anyone here have any ideas of what my problem could be. Any help would be appreciated!

[PLYNX]

Hey hello over there ! Ive read your post a couple of times and you dont say which car has the misfire ? The R32 or the R33 ? At a guess I'd say the first place to start would be putting a rising rate fuel pressure regulator on it as the Walbro pump is probably pumping past the stock regulator.

Let us know how you go !

[sxygirl]

Hey hello over there ! Ive read your post a couple of times and you dont say which car has the misfire ? The R32 or the R33 ? At a guess I'd say the first place to start would be putting a rising rate fuel pressure regulator on it as the Walbro pump is probably pumping past the stock regulator.

Let us know how you go !

Hi there Plynx - its the R33 thats misfiring - just got an HKS adjustable FPR (arrived today) and going to fit that midweek (if i can bear the cold as its supposed to be zero degrees tonight!!! if that fails its going to have to be the weekend as its dark at 4 .30pm now :-(. Desperate to get the car running properly

[Munkyb0y]

if it's a series 1 r33, it could also be the ignitor at the rear of your coil pack cover.

also you've said you changed the spark plugs, but what are they gapped to? should be no larger than 0.8mm for anything above stock boost.

Edited November 5, 2007 by Munkyb0y

[PLYNX]

Haha ! Zero degrees ! Move over here to Sydney ! Nice and warm by comparison But uts a bit cold here for summer at the moment (20degrees).

I have to second what Munkyb0y suggests also about the plug gap.

Also when you said you have changed the coils did you go brand new or second hand.

The R33 Series 1 are natorious for cracking. Some of the cracks being so fine it cant be seen with the eye. A good way to see if its arcing out of the coils is to take off the valley cover and secure the ignitor pack with cable ties and when its dark fire the engine and look of it arcing out of the coils.

[sxygirl]

Haha ! Zero degrees ! Move over here to Sydney ! Nice and warm by comparison But uts a bit cold here for summer at the moment (20degrees).

I have to second what Munkyb0y suggests also about the plug gap.

Also when you said you have changed the coils did you go brand new or second hand.

The R33 Series 1 are natorious for cracking. Some of the cracks being so fine it cant be seen with the eye. A good way to see if its arcing out of the coils is to take off the valley cover and secure the ignitor pack with cable ties and when its dark fire the engine and look of it arcing out of the coils.

The spark plugs are ngk iridium ones so i dont think (maybe wrong) but i dont need to look at the plug gap. The coilpacks Ive replaced with a wasted kit (brand new) . Had a look tonight and

it seems that a couple of the spark plugs arent sparking .

Oh, and 20 degrees!!!!! try one or two degrees!!! blooming freezing

Edited November 7, 2007 by sxygirl

[Crash.]

i had a problem with mine too, got new coil packs, changed the spark plugs, checked all the obvious but it still was happening.

Turned out to be the CAS....

If you know anyone with another skyline see if you can borrow there CAS and put it in your car, see if that makes any difference.... if it does then thats where your problem is, then all you need to do is go looking for another CAS to buy, a 2nd hand one should be fine.....

[Staffo]

Could also have dirty injectors in as well. They may need a clean

[Munkyb0y]

The spark plugs are ngk iridium ones so i dont think (maybe wrong) but i dont need to look at the plug gap. The coilpacks Ive replaced with a wasted kit (brand new) . Had a look tonight and

it seems that a couple of the spark plugs arent sparking .

Oh, and 20 degrees!!!!! try one or two degrees!!! blooming freezing

If you got off the shelf plugs to suit r33, they may have given you the 1.1mm gap, as thats what nissan recommends. But thats only good for stock boost.

Try gapping those plugs to 0.8mm. It costs you nothing, and you may find your problem right there.

[PLYNX]

Hey did you find out what your miss fire problem was ?