I'm stumped?? Car just stopping working :(

[s14det]

Last Wed I drove to work, came out about 9:30am in the morning and moved the car over to the parking lot. Came out at 3pm to leave from work and the car had a terrible idle. Was running really really rich and was popping and back firing at idle. (would only idle if i pressed the pedal down) I turned the car off, turned back on and still the same thing. I tried to drive it around the parking lot, but would go about 1 mph and was like it just did not want to go.

Now 2 times in the last month when I have stopped at Mcdonalds to get some breakfast, the car would be fine through the drive through, but once I paid for the food and then started to leave, it would not want to go. Would start to buck and top speed was about 2 mph. I would stop and turn off the engine wait about 1 min turn back on and would run fine. Then a few weeks later I stopped at Mcdonalds again and did the same thing. Now 1-2 weeks after that, it starts to do this. When I was in the drive-thu would idle like normal put once I start to go it would screw up.

Last week it would not idle unless I made it idle at 1500 with the pedal and was rich as crap and poping and such. I tried to fix it so I could drive it home. I disconnected the 300zx Maf and it would idle perfect put then it would act like it should with the MAF unplugged. Well Had to get my dad and his Jeep to tow me back home. (only 6 miles or so)

Since then I came home and disconnected the Maf again and still would idle like it is supposed to. Was rich at about 10-10.5 A/F and vac was about 17 or so which is normal for me. Pluged the Maf back in and car will not idle unless I make it and same poping and such. I re-connected the MAF and unpluged the TPS (like when doing timing) and it seemed to be a little worse then when the MAF was just unplugged. I thought it was the MAF so got another MAF and just tried that today and same symptoms. I started to unplug water temp sensor, TPS, MAF in all different orders and it will only idle/run when the MAF is unplugged which I am guessing is in SAFE mode. I'm stumped right now. I checked the codes and it is not posting any codes. It will post the MAF and the coolant (when unpluged)codes so those seem to be working.

This is with a Enthalpy ECU so it is a s13 ECU in a s14. Z32 MAF also. I checked the voltages coming from the MAF and it seems fine also. I guess I could check them at the ECU tho to make sure it is not a wiring issue. Hoping that somebody can give me some ideas to where I need to go next.

Thanks and sorry for the book Marcus

Modified by s14det at 9:14 PM 6/11/2007
Modified by s14det at 9:15 PM 6/11/2007

[coolbone28]

I just had the same problem. My car ran fine, and then i did some stuff with my o2 sensor and was testing the pins at the ECM. Well I go to start it and it idles like crap and it throws the codes 11, 12. MAFS and Crank angle sensor. Turns out that it was the harness adapter (i have an s14 with enthalpy ecu). I am guessing that maybe some solder came loose or whatnot. It also did it very sparadically.

[s14det]

So did you fix yours?

Mine only throws the code If I unplug the Maf or the Temp sensor. If I clear the ECU run it with everything plugged in I get code 55. (all is good)
Modified by s14det at 7:25 PM 6/11/2007

[S13FX]

Sounds to me like ypou MAF is FUBAR, or the wiring to the maf.

If you can try and get another Z32 maf and test it out.

[coolbone28]

ya. I just emailed chris at enthalpy and he responded real quick and sent another harness. Then i just shipped my old one back. I confirmed that mine was bad though. I pulled the ecu out and set it on the floor, cleared the codes, and started the car. It would idle perfect, then the slightest movement to the harness and it would stumble and throw the codes again.

[s14det]

I just got another Z32 Maf in today and nothing changed. I did move the ECU around thinking it could be a harness issue, but nothing really changed. I am starting to think it may be a wiring/connection issue.

[NateDogg]

Have you done the "wiggle test"???

Wiggle the connectors to the MAF, TPS, CTS, injectors, etc...Maybe the pins arent making good contact?

[s14det]

Yea did that to. Sprayed some cleaner in there to clean the contact out and still nothing