Okay so i have a 2003 Z M/T 135,XXX. I just got the car recently as a project, and was aware it wasn't in the best condition. After long searching from multiple sources and finding nothing, I'm hoping some of my fellow Z friends can help me out.

So first the SES light came on for an 02 sensor and the seemingly infamous P0300 (Random/Multiple misfire). The car was showing no signs of a misfire whatsoever. Anyway I was changing the old outdated spark plugs and noticed some oil in the plug well, so I put it back together still with the new plugs (there was nothing i could do about the oil at the moment). I crank up the car and NOW I can definitely tell that its misfiring, turns out it was just a vacuum leak. A day or two go by and I decided to change my valve cover gaskets, I was however uninformed and didn't know that you have to change the whole cover itself. So I put the car back together everything plugged up correctly and start it up. The car started perfectly didn't seem to have and issues or anything. Now I'm out for a test drive and she decided to just die on me, so i pull off to the side no crank. I played with the hose thats connected to the plenum and the PVC valve and it started up again (where the cracked hose was discovered too). Driving back home I couldn't take the car over about 3k RPM with it sputtering. After some research I figured I had to relearn my ECU accelerator pedal, throttle body, ect. no luck. A day later, after many attempts it will crank but just die or idle for a few seconds then die. Finally I get it to idle and decide to go for test drive #2. I stopped at a red light and the car died, after nearly 2 hours it finally turned over and i was able to get it home. Now the car is just cranking and wont fire up. If anyone has some tips/help/advice id greatly appreciate it. I tried to be as detailed as possible, thanks guys !

 

Welcome- you've got a lot of problems with your "project" Z. They're going to be difficult to sort out and we can only offer limited help on an internet board. Some questions to start:

-what kind of plugs did you use to replace the old ones?

-Have you checked for any codes from your diagnostic programming?

-Did the previous owner mention any problems with starting or idling?

-Have you done any checking or work on the MAF?

 

1. I used NGK iridiums
2. I dont have access to a scanner but for the time it was running there was no SES (I know that doesnt necessarily mean anything)
3. Previous owner never metioned anything, ive had the car a little over a month and never had and problems like this till I changed the plugs and such.
4. the only time i touched the MAF was when i was taking off my intake.

-Could it perhaps be a fault during the reassembly ? Im getting new valve covers ASAP!

 

Since the only thing that's changed is your work on the car, I'd say it's most likely a problem with reassembly that's caused the issue. So go back through what you've done and recheck torque values and how you put things together. Also, which model of NGK Irridiums did you use?

Failing that, I'd pull the codes somehow and see what the diagnostic system says...

 

OKAY, so i got all the new pieces (iridium ix on those plugs btw) and now i believe im experiencing a dead battery. Flashing lights on the dash, starter rapid clicking blah blah. This person had a bunch of grounding wires on the car that i took off, i hope that didnt mess anything up (not sure if thats possible) but yeah my windows wont even roll up. -_-

 

Okay so i installed everything (valve cover, even got a new plenum gasket, and got a z1 plenum spacer). So i got the car running and driving, wohoo, right? well, unfortunatley wrong. The car was running slightly rough so i went through the relearning procedure. I did the accelerator pedal and throttle position relearn. after i did the the idle air volume learning car started misfiring even worse than before. Now i go to retry it again and when i turned the key to "on" i heard a small pop and now the car wont start. i checked all fuses that thought would have blown all seem to be good. any though would be a big help

 

Sorry to hear your continued problems- could you tell where this "small pop" came from? Have you checked the IPDM itself?

 

I checked fuses ON the IPDM, if you're talking about checking it as whole I'm not sure how to do that.

 

That's right- you just need to check all the fuses under the IPDM cover and in the fuse box in the DS footwell. Again, could you tell where this "pop" came from?

 

Did you complete the throttle body relearn/reset process after putting everything back together?

 

okay I checked all the fuses, the only ones that didn't make the test light go off were on the IPDM. On the right side below the ign contr. the 2 15A and 10A fuses, but they're not blown. The pop came from the engine bay. No codes no nothing the only thing my scan tool is showing is the following.

 

Yep it was after doing all of the relearning that I heard the pop, and my car failed to start.