2004 G35 Help!!

[tuner117]

hey guys, so recent projects that are going on have me and all my friends and family (gearheads) stumped. The car has a VQ35DET with a slight bore (from 3498cc to 3517 very very slight) forged internals, ported and polished valve ports, 740cc injectors, tune, lower compression pistons (10.5:1 to 8.5:1 roughly) 63mm turbo with a custom exhaust. The car was running, driving and boosting, then stalled out, got it going again, drove it a foot and it died out again. So now its in the shop, cant find the problem being it wont start. It turns over, kicks once and a while but will never stay running. It has 6 month old gas so that may be it as well. If anyone could even give us some ideas that would be freaking fantastic, i have a video of us trying to start it will post when i can move it from my phone to computer. Really appreciate it! if anyone has any question about anything let me know!!

Thanks
Brayden

[sr20s14zenki]

Fuel pump?

[tuner117]

Its getting fuel, compression and spark so i dont know why it wouldnt fire, might be getting to much fuel causing it to flood right away

Brayden

[AndyL]

Crank and/or cam position sensors?

[Chantastic]

I also have a weird G35 problem, sorry to hijack the thread. Maybe it would provide some insight as well though? I have a 06 G35 with just exhaust mods. Sometimes it starts after a moment of hesitation, other times you keep cranking it for a few seconds and then it goes. Other times you can it six times in a row before it starts. It's a new battery, and I also replaced the fuel pump. I had the camshaft position sensor (driver side) changed out and that didn't do anything either. Then a check for continuity from there and it checked out fine. Grounds have also been checked. Plugs changed recently.

Help.

:(

[tuner117]

Originally posted by Chantastic
I also have a weird G35 problem, sorry to hijack the thread. Maybe it would provide some insight as well though? I have a 06 G35 with just exhaust mods. Sometimes it starts after a moment of hesitation, other times you keep cranking it for a few seconds and then it goes. Other times you can it six times in a row before it starts. It's a new battery, and I also replaced the fuel pump. I had the camshaft position sensor (driver side) changed out and that didn't do anything either. Then a check for continuity from there and it checked out fine. Grounds have also been checked. Plugs changed recently.

Help.

:( i personally would suggest doing spark plugs and or coilpacks

[Chantastic]

Originally posted by tuner117
i personally would suggest doing spark plugs and or coilpacks

Plus have already been changed, I'll do some coil pack research. Thanks!

EDIT: Fixed! Turned out that there are two sensors per bank, not one! Changed the other one on the driver side out and all is well again!

[tuner117]

Originally posted by Chantastic


Plus have already been changed, I'll do some coil pack research. Thanks!

EDIT: Fixed! Turned out that there are two sensors per bank, not one! Changed the other one on the driver side out and all is well again! Glad your G is working again!

[tuner117]

Any other suggestions? Aha literally anything, cant find the problem anywhere

Thanks
Brayden

[gretz]

Take those injectors out and have them cleaned / flowed....cost effective and you can cross that off the list
Call performance fuel injections (Stefan) and get them done...

[ae92gts]

Originally posted by tuner117
Its getting fuel, compression and spark so i dont know why it wouldnt fire, might be getting to much fuel causing it to flood right away

Brayden

Have you tried swapping out the gas yet? By the sounds of it, I'm leaning towards a fuel problem. Either an injector problem as stated above or its bad gas. Also have you checked the compression lately?

[Chantastic]

Originally posted by tuner117
Glad your G is working again!

Thanks! Best of luck with yours!

[tuner117]

Thanks guys for the suggestions! Now it seems to be firing cylinder 1 only once then it wont fire again, any ideas on that?

[350ZAl]

Pull the plugs and look at the plugs. That will give you some indication if there is an issue in one or more cylinders.

Make damn sure you have the coil pack connectors going to the right coil packs, this is an easy thing to mix up on these cars. I did it on mine, swapped 1 & 3, car ran, but had a mean misfire.

Also, check the MAF sensor and connector/wiring, when mine was fucked car would start, stumble then die right away. Couldn't keep it running.

If you have a way to pull codes, do that, it may also offer some insight.