ZLover4Life

It's not your fuel pump.

So it's fine when idling? And you're now saying "missing noise." Does that mean it does not feel like it's missing? There's a big difference between sounding like its missing and actually misfiring.

KasbeKZ

have the ecu codes have been checked? the idea that it may only be a noise makes me think that it may be detonation. it is happening under load right?

rtmorgan

well it sounds like to me you have issuse when your engine is underload and or your cars body is under stresses.

first things first pull every single connector apart and clean them and mabe put some dieletric grease on them and if needed tweak the male side prongs in the connector anout 20-30 degrees so you get a good connection if needed zip tie your connectors together so they wont become loose if the clips are broken. it sounds like you have a simmilar problem that i had when i first got my car. ONE of your ptu wires may be loose (one cylinder mis firing).
do all of this and then let us know what happend.

most important things to check
maf
cas
ptu
all injectors
all coils

jaredjmoore89

I found something but im not sure if it makes a difference. What are the 2 hoses that run into the catylytic converter. I have test pipes and they are blocked off really tight with large bolts. Is that alright or do they need to be removed. Also the ptu is new so is the wiring harness but when i took the throttle position sensor plug off i noticed it had 3 prongs inside the sensor but only 2 in the plug. Is that my problem os is it supposed to be that way. It the mounted part of the sensor by the way.

rtmorgan

its supposed to be that way the egr on your car sounds like it has been bypassed so forget about the egr and all its related components there not your problem.
i think you have a faulty wire or plug somewhere

your tps plug is fine

rtmorgan

for good measure tweak the male side prongs in the connector anout 20-30 degrees so you get a good connection. do this to the ptu and maf and let us know what happens

jaredjmoore89

What bout the gap on the spark plugs. No ecu upgrade what do i need to gap them to, i think the guy at z1 said like .38 today i forgot . I thought the plugs were pre-gapped but guess not. I still dont think that would cause all thisthough. Also when i unplugged the mounted part of the tps sensor nothing happened. No change in sound or anything. The other part made it idle really high but the black did nothing.

jaredjmoore89

And yeah ill try that next i havent even looked as the MAF sensor.

rtmorgan

thats normal
and yes plug gap can make or break a car do that immedialty thats is probally your biggest poblem right there whaen you said the plugs were new i bet everyone assumed they were gapped correctly

ZLover4Life

The hoses he's talking about are not related to the EGR, they are the AIV's, and they are still useless (any car with an aftermarket ECU bypasses their function to begin with, and they were removed by Nissan in 1992 I believe). The EGR is fed through a solid pipe off the driver's side manifold.

I'll think about the issue and post back later - I just wanted to correct that.

rtmorgan

oh yeah thats right the aiv i completly forgot about those lol.

jaredjmoore89

What do i need to gap them too.

rtmorgan

they should all be the same at .044

91zxtt

When you say missing noise are you talking about a back fire? When you're on the throttle hard, do you feel it or do you just hear it? I had an issue with mine mis-firing when I was hard on the gas. It turned out to be the CAS.

jaredjmoore89

Its not like a backfire miss fire and yes i feel it tremendously. Its kinda of like a studder. I mean it shakes and everything. Also i checked my gaps they already were at .044 and i tried swapping around my coil packs. The coil pack that was on cylinder 6 made a sparking sound all the time and the guy at z1 said its common for a cylinder to do that, but when i swapped the coil packs around i noticed its not the cylinder thats doind the ticking its the coil pack. Does that mean the spark on the coil is not making it all the down to the plug or its bad.

ZLover4Life

Coil packs frequently make noise of that sort - it's nothing to be worried about.

You need to start answering questions and explaining the problem more thoroughly.

91zxtt

Watch your tach when you're driving.....I noticed when my CAS failed that tach would bounce all over the place when it would miss.

jaredjmoore89

I called around and called a nissan dealer and talked to a guy that works on z's and told him my problem. I told him that my coil pack made a sparking sound and he said that the spark was sparking inside the coil pack rather that transferring it to the spark plug. Sure enough i changed it out and its running like its never ran before. Weird thing is im boosting 13 lbs of boost. Is that normal. I thought after 12 i had to get some kinda jet that allowed more air flow and if not it would cause detonation or something like that.

ZLover4Life

Are you kidding me? So when I told you to swap coil packs with another cylinder and see if the misfire followed the coil pack, you didn't do it? That would've answered your damn question right there.

And no, it should not be boosting over 9psi without boost jets or a boost controller. The gauge can be inaccurate though.

jaredjmoore89

I did swap all the coil packs and the miss stayed the same. He said the reason is that the coil pack was working but not to its fullest. It had spark but was letting most of it out before it got to the plug.

ZLover4Life

... if you put a good coil pack on the misfiring cylinder (and the miss is truly because of the coil pack), then the cylinder that was misfiring would start firing...

jaredjmoore89

It only misfired when i got on it real hard. When at idle and cruising it was fine so the miss was the same throughout all cylinders and the difference was innoticeable. Talked to a guy at z1 bout the boost pressure and he said if its boosting 13 lbs just to look at it as a way that i dont have to get the upgrade aand that it would be fine.

ZLover4Life

LMAO @ Z1's comment. That's why a LOT of people complain about them. 13psi on a stock program can blow your engine.

And if it's misfiring under load, you could've probably just tugged on the throttle cable to get it to misfire and found out if it was the cylinder with the suspect coil pack by doing so.