1991 Nissan 300ZX twin turbo

[Calebbradley1996]

I have a 1991 Nissan 300zx tt. It was misfiring but if was every once in a while. I took plugs out regapped them to .034. Then checked the resistance of my cool packs. They are all 1.5 ohms. Then listened to to the injectors and they sound operational. After I did these small things my misfire is very consistant now, not power and it sounds like a motorcycle... I need some help!!!!!

[DCaff300ZX]

Have you checked the injector connectors and others for the dreaded green corrosion?
With the weather going cold/wet, things will begin acting up in this area if so.
Also, a power balance test (pulling coil pack plugs one by one) will help locate the cylinder with the problem, if that is where the problem is.

[ThisIsSparTTa]

If you still have old style injectors, its likely that one or more are partially failing or always failing: http://z32.wikispaces.com/Fuel+Injector

[Calebbradley1996]

No build up or anything.. Even new plugs didn't help. Functional injectors, great compression, good compressions in the cylinders as well... Very stumped.

[NolimitZ32]

Triple check your injector clips and continuity on the injector wires. If you can, get a hold of a good known ecu, injector drivers in the ECU do go bad sometimes.

[ThisIsSparTTa]

Injectors being "functional" or clicking doesn't mean anything. You need to ohm them.

[Calebbradley1996]

The ohms are around 13 but ones leaking gas out of the top. The misfire went that sounded like a motorcycle went away today... Didn't do anything. Now the car won't start just cranks over and floods the engine. Still a slight misfire, wet plugs from gas so I believe I have bad injectors even though the ohms are correct. Kind of a mystery car... Things come and go not to sure of the problems

[NolimitZ32]

Wait a second, you have an injector spilling out the top (as in cracked housing or very bad ring) and you are looking for other issues? Fix known issues first, otherwise you'll be chasing your tail forever.

[Calebbradley1996]

That is a good place to start... But the cracked injector is on a cylinder that is firing. I still have two cylinders on the right bank that are not firing. And the car is running very rich which is expected from the miss on the two cylinders. I purchased new injectors which should be in early next week, new hotter plugs, and new coils

[DCaff300ZX]

As NoLimit says, you need to go about your detective work in a certain way, and fix any and all obvious issues FIRST before moving forward. The online service manual is a good place to start, and other online sources such as TT.net and others have how-to's and ways to go about checking the various issues a VG30DETT and VG30DE have and are known to have at times given certain mods or climates.
I advise you to do some research and follow the guides explicitly (such as ohm-ing the injectors not the coil packs) to have the best chances to fix your car yourself...otherwise a veteran Nissan Z mechanic is your best bet.
Free fish for the day to get started...:
http://www.ttxtz.com/tech.html

http://300zx-twinturbo.com/cgi-bin/manual.cgi

[Trimble Epic]

Jesus, its Leaking fuel out the top of a cracked injector and you're still driving it? Stop!!!

[NolimitZ32]

What was your resoning behind buying Hotter plugs? These engines tend to ping when they don't get the proper treatment and putting in hotter plugs will only make the issue worse.