bumble zee Posted June 8, 2006 Share Posted June 8, 2006 I am running the 81zxt ECU and ignition. Overtime of a couple weeks my Z will slowly start to lean itself out. If I swap out ECU's, it will run normal and the mixture is normal, but it will still slowly lean itself out all over again. Anyone ever have this problem before? I have a Walbro 255 fuel pump, it doesnt loose pressure, and i am running the stock zxt fpr. I have 370cc Svo injectors. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted June 8, 2006 Share Posted June 8, 2006 Bumble - How are you running such large injectors with the stock ECU? Did you play with your AFM? I am running the same Walbro as you but in conjuction with an Aeromotive FPR...stock injectors (for now) Yasin Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted June 8, 2006 Share Posted June 8, 2006 I don't personally have experience with zxt electronics, but could the plug going into the ecu be loose or corroded? A lot of people have complaints about it. Quote Link to comment Share on other sites More sharing options...
bumble zee Posted June 8, 2006 Author Share Posted June 8, 2006 Yes my AFM is dialed back, and I dont believe my plugs for the ECU are loose. I have went through them before and tightened them. I am going to dissconnect my knock sensor for a trip and see if it is picking up my exhaust since it is a straight pipe out of the side. Yesterday I just went through my plugs and checked an re-gapped if nessasary them to .030 for the higher boost, I am running 12psi. That should be a fine gap for that I would think. Quote Link to comment Share on other sites More sharing options...
bumble zee Posted June 9, 2006 Author Share Posted June 9, 2006 What are the odds?? Battery stopped accepting a load and got stuck at work. But the knock sensor wasnt it, still does it, swapped ECU's and AFM's. Going to get a new O2 sensor tomorrow, mine is about 3 yrs old and I run rich so maybe its bad, also going to test my head and water temp sensors tomorrow also. Quote Link to comment Share on other sites More sharing options...
Mex-Z-can Posted June 9, 2006 Share Posted June 9, 2006 How do you know that "it doesn't loose pressure"??? Do you have a pressure gauge on the dash or any other way to check your pressure on real time??? I ask because it sounds like a bad fuel pump or FPR. But if you really can check the pressure as you drive, and it still leans out then I guess it's something else. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted June 11, 2006 Share Posted June 11, 2006 Are you measuring mixture with a wideband? If so, how much is it changing? Is it leaning out at idle or all over the load range? Need more info. Quote Link to comment Share on other sites More sharing options...
oinojo Posted June 11, 2006 Share Posted June 11, 2006 try running it without the o2 sensor. I know my z ran better without it for some weird reason. I guess it throws it into a limp mode and runs richer. Quote Link to comment Share on other sites More sharing options...
bumble zee Posted June 13, 2006 Author Share Posted June 13, 2006 Yes I have a fuel pressure gauge sticking out of my cowl and I can watch it in real time. As for running lean anywhere in the rpm range it stays consistant. Just slowly leans out as the rpm's go up now. The fuel pressure goes up a consistant 1psi to every 1 psi of boost. No I dont have a wideband and I am not taking my mixture gauge as accurate, I just read the green and the red, and when it hits red I can feel the difference in the lack of power. I guess I could take a video of it... I am stuck at 10 psi because if I go any higher, it goes full red. Quote Link to comment Share on other sites More sharing options...
bumble zee Posted June 13, 2006 Author Share Posted June 13, 2006 Ok, got video click to play Quote Link to comment Share on other sites More sharing options...
bumble zee Posted June 14, 2006 Author Share Posted June 14, 2006 Well changed out the fpr to a z31 turbo regualator, up's the fuel pressure about 5 to 10 psi, and that seemed to make the difference. pulls good, never goes into the red at WOT, so hopefully it was just a fuel pressure thing this time. Quote Link to comment Share on other sites More sharing options...
280Z Turbo Posted June 14, 2006 Share Posted June 14, 2006 Aaron, you've gotta do that Z31 MAF swap! You're lucky that your car even runs! I went over to Jason's house tonight to pick up a MAF and ECU from him. It doesn't sound too hard. Quote Link to comment Share on other sites More sharing options...
Mex-Z-can Posted June 14, 2006 Share Posted June 14, 2006 Glad to see that you found the problem. Thanks for posting the results. Quote Link to comment Share on other sites More sharing options...
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