New guy here, figure I'll jump right in.
I'm having some issues right now with a friends car , 94 z, Na auto , sometimes runs perfect, then out of the blue, runs like total ***, running rich, low erratic idle, , when he first brought it to me I jiggled the CTS and the car stalled, so I pulled off the connector and it was all corroded , cleaned it up really good checked the sending unit, speced ok, and had to install a new locking clip,Funny thing is it wouldn't run at all with it unplugged. Ran great for a full day, thought I had it licked then the next day, back to spitting and spuddering, no rhyme or reason, hot cold, rain shine has new plugs, new style PTU, and I checked every connection and they are all clean,and make no difference when you move em around .Only code I had was for the knock sensor, but that really wouldn't cause it to do what its doing, and I figure that the PTU isn't bad , or it would be doing it all the time. BUT one thing I have noticed, is that when it does it, Soon as you turn the key off, it clears right up and stays running perfect for about 5-7 seconds then shuts off. I'm at a loss.

 

omg. someone put a turbo timer on a n/a.

jkjk

looks like one thing to check would be the ignition switch/harness. take the steering column cover off and you'll see it. i want to say it goes for about $30, but it's very easy to test before you replace it. well... maybe not easy to test if it's intermittent.

 

Would the Knock sensor harness being bad , make the car act as crappy as it does? The after run doesn't happen all the time, just sometimes and its not always when it runs crappy.I tried the check the PTU as the service manual says, but with it being replaced with the new one all the terminals are numbered wrong so I'm not sure I'm even going it right.

 

wow 79 views and 1 half answer, thanks for the support, glad I'm not the guy that owns this turd.

 

Hello?

 

gee guys, glad this place it a ton of help.

 

Do a search here and on twinturbo.net; it will turn up some good stuff. If not post on TT.net

 

Clean the Mass Air Flow sensor i found that to help me out alot. They sell it at advance auto parts its a little pricey though 12.99 ? but worth a shot !

 

maf doesn't affect idle

 

No on the knock sensor. Without any ECU codes, some of the basics would be to check fuel pressure and check for vacuum leaks. When it's running, does the exhaust smell rich?

 

apparently it does, before the car wouldn't run, found a new rebuilt MAF on ebay for 65 bucks and installed it, and now it revs and drives normal, BUT its missing at idle, I suspect the plugs are all jacked up from the running rich before.

 

an injector(s) could be bad too.

easy test with a volt meter, i dont remember the specs but look it up, its on here.