1993 300zx TT stuborn missfire - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Radioadix · 07-09-2013, 08:16 AM

A friend and I recently picked up a 93 twinturbo. This is a current list of what has been done to the car thus far:
Battery
Spark Plugs
UIM Gasket
Injectors
PTU Ignition
Fuel Filter
Clutch Slave Cyl
Clutch Cables
Clutch Master Cyl
Compression test confirmed 170+ each cylinder.
Grounding kit

At this time, Cylinder 5 will not fire. We have used a test plug and confirmed that there is spark. We have checked the voltage to each line. the plug is wet with gas when removed, we have swapped the coil pack with a cylinder that is for sure firing. The next step we are about to take is to replace the entire wiring harness just to eliminate that as a possibility but wanted to check on here to see if anyone else has experienced anything like this and what possible fixes you guys can offer. Any help is appreciated. Thanks in advance.

typhoonslippery · 07-09-2013, 08:44 AM

did you try replacing the vg30 ? I hear they are usually the issue

injector stuck open ?

Radioadix · 07-09-2013, 08:51 AM

I guess your a 240 guy.. lol

The injectors are all brand new.

typhoonslippery · 07-09-2013, 08:54 AM

sorta

I remember working on a few of them and the coil pack harnesses were always brittle and had cracks as well as the coil packs themselves were always needing to be replaced like in a ca18det engine.

New injectors don't always mean 100% ... they can be stuck

Radioadix · 07-09-2013, 08:56 AM

We swamped the coil pack for cylinder 1 which is 100% for sure working. and still got nothing although with a test plug running off of cylinder 5's coil pack and - we got spark. We also replaced the plug in that cylinder yesterday and its still not firing.

Radioadix · 07-09-2013, 08:57 AM

We have also checked the voltage on each line at the clip for the coil pack

double_R · 07-09-2013, 09:18 AM

Where did you get the injectors from? I had to replace my injectors before even if I got em brand new.

PoorMans180SX · 07-09-2013, 09:21 AM

Check compression on that cylinder. I had a problem exactly like this. Turned out compression was 90psi on that cylinder. Bye bye VG30, hello 1JZ...

Radioadix · 07-09-2013, 09:26 AM

Injectors are from advance auto parts - and the compression check has been done - 170+ on each cylinder.

Hopefully we do not have to replace the injectors - that was not a fun job removing the intake.

double_R · 07-09-2013, 09:34 AM

Swap your injector with another working one and see what happens. Could be the harness and hopefully its fixed when you replace it.

double_R · 07-09-2013, 10:03 AM

Ohm test the injector also.

jr_ss · 07-09-2013, 11:30 AM

Why don't you put a noid light on the injector clip to see if it's even getting signal?

JeeBus · 07-09-2013, 08:54 PM

injector stuck open or pinched seal.

Both will flood that cylinder and keep it from firing, hence why the plug on that cylinder is wet.

07-09-2013, 08:16 AM	#1
Radioadix Join Date: Jul 2013 Location: East Tenn Age: 33 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	1993 300zx TT stuborn missfire A friend and I recently picked up a 93 twinturbo. This is a current list of what has been done to the car thus far: Battery Spark Plugs UIM Gasket Injectors PTU Ignition Fuel Filter Clutch Slave Cyl Clutch Cables Clutch Master Cyl Compression test confirmed 170+ each cylinder. Grounding kit At this time, Cylinder 5 will not fire. We have used a test plug and confirmed that there is spark. We have checked the voltage to each line. the plug is wet with gas when removed, we have swapped the coil pack with a cylinder that is for sure firing. The next step we are about to take is to replace the entire wiring harness just to eliminate that as a possibility but wanted to check on here to see if anyone else has experienced anything like this and what possible fixes you guys can offer. Any help is appreciated. Thanks in advance.

07-09-2013, 08:44 AM	#2
typhoonslippery Zilvia Addict Join Date: Nov 2003 Location: Canada Posts: 812 Trader Rating: (10) Feedback Score: 10 reviews	did you try replacing the vg30 ? I hear they are usually the issue injector stuck open ? __________________ CA18 is the only way to go!

07-09-2013, 08:54 AM	#4
typhoonslippery Zilvia Addict Join Date: Nov 2003 Location: Canada Posts: 812 Trader Rating: (10) Feedback Score: 10 reviews	sorta I remember working on a few of them and the coil pack harnesses were always brittle and had cracks as well as the coil packs themselves were always needing to be replaced like in a ca18det engine. New injectors don't always mean 100% ... they can be stuck __________________ CA18 is the only way to go!

07-09-2013, 09:18 AM	#7
double_R Leaky Injector Join Date: Dec 2003 Location: Norcal Posts: 56 Trader Rating: (0) Feedback Score: 0 reviews	Where did you get the injectors from? I had to replace my injectors before even if I got em brand new. __________________

07-09-2013, 09:21 AM	#8
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 36 Posts: 5,573 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	Check compression on that cylinder. I had a problem exactly like this. Turned out compression was 90psi on that cylinder. Bye bye VG30, hello 1JZ... __________________ Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs.

07-09-2013, 08:51 AM	#3
Radioadix Join Date: Jul 2013 Location: East Tenn Age: 33 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	I guess your a 240 guy.. lol The injectors are all brand new.

07-09-2013, 08:56 AM	#5
Radioadix Join Date: Jul 2013 Location: East Tenn Age: 33 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	We swamped the coil pack for cylinder 1 which is 100% for sure working. and still got nothing although with a test plug running off of cylinder 5's coil pack and - we got spark. We also replaced the plug in that cylinder yesterday and its still not firing.

07-09-2013, 08:57 AM	#6
Radioadix Join Date: Jul 2013 Location: East Tenn Age: 33 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	We have also checked the voltage on each line at the clip for the coil pack

07-09-2013, 09:26 AM	#9
Radioadix Join Date: Jul 2013 Location: East Tenn Age: 33 Posts: 5 Trader Rating: (0) Feedback Score: 0 reviews	Injectors are from advance auto parts - and the compression check has been done - 170+ on each cylinder. Hopefully we do not have to replace the injectors - that was not a fun job removing the intake.

07-09-2013, 09:34 AM	#10
double_R Leaky Injector Join Date: Dec 2003 Location: Norcal Posts: 56 Trader Rating: (0) Feedback Score: 0 reviews	Swap your injector with another working one and see what happens. Could be the harness and hopefully its fixed when you replace it. __________________

07-09-2013, 10:03 AM	#11
double_R Leaky Injector Join Date: Dec 2003 Location: Norcal Posts: 56 Trader Rating: (0) Feedback Score: 0 reviews	Ohm test the injector also. __________________

07-09-2013, 11:30 AM	#12
jr_ss Post Whore! Join Date: Dec 2005 Location: Pa Posts: 6,412 Trader Rating: (35) Feedback Score: 35 reviews	Why don't you put a noid light on the injector clip to see if it's even getting signal? __________________ My SR20VET Does your VTC gear rattle in your S14/15 SR? PM me.

07-09-2013, 08:54 PM	#13
JeeBus Leaky Injector Join Date: May 2011 Location: ATL Posts: 66 Trader Rating: (4) Feedback Score: 4 reviews	injector stuck open or pinched seal. Both will flood that cylinder and keep it from firing, hence why the plug on that cylinder is wet. __________________