Cylinder #1 is dead 93 NA

[Nareally]

(1993 300zx NA 119,235miles) I've read several different forums on dead cylinders for several weeks now but still cant get my problem solved. I've swapped coil pack, and spark plug from a good cylinder, and even replaced all spark plugs with ngk, (even after the fact of swapping cop/plug), I've replaced all injectors, Timing was off a bit so I set it @ 15, Ran PTU test -GOOD-, Got rid of the sub harness, Checked Voltage coming out of PTU on all 6 Wires they all Read the same voltage, above 13vdc, Performed a compression test, Dead cylinder is @ 170,(good) I've cleaned all corroded terminals under the hood, added dielectric grease to all,

(including the CAS) and even the fuses! as well as checked all fuses/relays from inside the car to under the hood, R&R fuel pump controller, Plenum Gasket, Valve cover gaskets, TB gaskets, fuel Rail O rings and Temp sensor,(All parts came from Nissan or z1 motorsports), cleaned the iacv/aac valve, I've tested voltage going to the coil pack as well as the injector, (good voltage on both) Not showing any codes But 55 of course.. I'm in a bog down mode here, Any Help would be great. (All Diagnostics have been done while car was @ normal Op Temp) Other then that it has z1 eprom chip in ecu( I've pulled out the chip just to see if any difference, NONE) H pipe, TT mufflers, JWT POP, and headers. All of the "performance parts" were added @ 80k miles and ran good for a NA, but now its like driving my 88 s10, well maybe not that bad, ha,again thanks for all the Responses!

[nissanfreak12]

Pinched o-ringis all I can think of at the moment. Have you tried a leak down test? The ECU also could have an issue with it unless you tried a DIFFERENT ECU. I had a friend lose a driver for one of the cylinders, couldn't figure it out till he tried a different ECU.

[amiry36]

Whats the condition of sparkplug for the dead cylinder? Is it wet?

[Nareally]

Thanks for reply, no I haven't done a leak down test yet but will, and I was thing to try another ecu, the spark plug was wet of gas when I pull it out

[amiry36]

If the spark plug is wet, then you either are not getting a spark or getting too much fuel. Ohm test the injector on cylinder #1. I know you said you have replaced the injectors but this test wont take you that long. Simply put your multimeter on ohm setting and connect it to the two prongs of the injector. The reading should be within 10-14 ohms. Tell us what happens. And for the spark plug, i suggest to check the spark plug hole on cyl #1. It could be dirty or oily; causing the spark plug to not get a good ground connection from the cyl head.

[Nareally]

Yes the ohm test I did to all New injectors after they were installed, but now I did have oil down around that plug, I'll try removing the plug and cleaning, I've had coil pack and plug out to see if it made spark, it does, thanks again

[Nareally]

I apologize for no responses yet, we just had a baby (Sophia) 7-3-14 @10:08 pm so it's gonna be a couple of weeks before I get back on the z but will post what I find out!

[Nareally]

Ok seems nissanfreak12 was right! I had it running today, I pulled the injector plug and cop plug and engine didn't change, I plugged JUST the cop back up and noticed the engine got higher, so realized that fuel was passing by the injector, pulled the injector and the bottom O ring was destroyed, I must not have installed the injector right, anyways I put a new O ring on it and now she's purring like a kitten! For now that is, but I still think my ecu is messed up, when I pull the z1 EPROM chip out of the bed socket and turn the key on the a/c condenser fan turns on, and the car absolutely shakes like crazy and dash is lit up like a Christmas tree, when I put the chip back in all of that goes away... So my next step is to replace the ecu, again thanks everyone for all the great responses!!

[nissanfreak12]

Ok seems nissanfreak12 was right! I had it running today, I pulled the injector plug and cop plug and engine didn't change, I plugged JUST the cop back up and noticed the engine got higher, so realized that fuel was passing by the injector, pulled the injector and the bottom O ring was destroyed, I must not have installed the injector right, anyways I put a new O ring on it and now she's purring like a kitten! For now that is, but I still think my ecu is messed up, when I pull the z1 EPROM chip out of the bed socket and turn the key on the a/c condenser fan turns on, and the car absolutely shakes like crazy and dash is lit up like a Christmas tree, when I put the chip back in all of that goes away... So my next step is to replace the ecu, again thanks everyone for all the great responses!!

Thats great and congrats on the baby!! Thank you for the update, most people do not post what fixed the issue.