ryan95i4 Posted June 7, 2012 Share Posted June 7, 2012 (edited) 73 w/ 83 L28ET, Stock ECU, Stock Turbo Injectors Idle fuel pressure set to 36psi Wideband is pegged at 10:1 at idle and almost everywhere below 3500rpm or so, so its probably running even fatter than that, black smoke and all. Im new to the AFM setup, so I dont even know where to start. Ive searched and found lots of threads on carbed setups running rich, and some NA threads, but having trouble finding threads with the same issue. Is there an adjustment at the AFM to lean the mixture down low? How do most people tune the L28ET w/ a stock ecu? Motor runs well other than being pig rich. Only other issue are cold starts take several attempts and car doesnt want to hold an idle until warm. Once its warm, it just runs really rich. Thanks for any help or pointing me in the right direction. Edited June 7, 2012 by ryan95i4 Quote Link to comment Share on other sites More sharing options...
NewZed Posted June 7, 2012 Share Posted June 7, 2012 Have you checked all of the components using the 1983 FSM? If the swap was straight across, no modifications, from an 83 to your car, that would be the place to start. It shouldn't need "tuning" if it's stock. The pieces are designed to work together as-is. www.xenons130.com/reference Here's a popular swap link - http://forums.hybridz.org/index.php/topic/38461-240z-260z-280z-turbo-swap-guide/ Quote Link to comment Share on other sites More sharing options...
ryan95i4 Posted June 8, 2012 Author Share Posted June 8, 2012 I have the FSM but havent had a chance to begin my search yet. Was just wondering if there was any common cause for a rich condition where I should begin my search. Quote Link to comment Share on other sites More sharing options...
cgsheen Posted June 8, 2012 Share Posted June 8, 2012 The FSM has very good trouble shooting steps and all the tests on the ECCS are fairly simple if you have a multimeter in hand. Most of the problems on the L28ET come from poor, corroded, and/or missing electrical connectors/connections and/or vacuum hoses/connections, cracked intake boots. Check and clean them all, replace if necessary. Specifically at startup, a malfunctioning Air Bypass Valve on the intake manifold, and/or a malfunctioning A.A.C. valve will cause a rich condition. The Air Bypass is electrical, the A.A.C. is vacuum (controlled the the VCM (Vacuum Comtrol Module) - which is a couple of vacuum solenoids that the ECU uses to control the A.A.C. and EGR valves). You can check that, but I'd recommend you going through the entire ECCS system and follow all the trouble shooting steps in the FSM. Many people jump at the AFM, thinking they can make adjustments, when it's the LAST thing they should do. If all the other parts in the ECCS system are working properly, connected properly, there's no reason to bust open the AFM. Quote Link to comment Share on other sites More sharing options...
450HPZ Posted June 9, 2012 Share Posted June 9, 2012 73 w/ 83 L28ET, Stock ECU, Stock Turbo Injectors Idle fuel pressure set to 36psi Wideband is pegged at 10:1 at idle and almost everywhere below 3500rpm or so, so its probably running even fatter than that, black smoke and all. Im new to the AFM setup, so I dont even know where to start. Ive searched and found lots of threads on carbed setups running rich, and some NA threads, but having trouble finding threads with the same issue. Is there an adjustment at the AFM to lean the mixture down low? How do most people tune the L28ET w/ a stock ecu? Motor runs well other than being pig rich. Only other issue are cold starts take several attempts and car doesnt want to hold an idle until warm. Once its warm, it just runs really rich. Thanks for any help or pointing me in the right direction. I would start by checking the head temp sensor resistance at the ecu... Quote Link to comment Share on other sites More sharing options...
ryan95i4 Posted June 11, 2012 Author Share Posted June 11, 2012 So now I have the complete opposite problem, way lean at full throttle. My car was running pig rich and had trouble idling and starting cold; battery needed to be replaced and found a leak in the coupler before the throttle body. Fixed those, now the car idles perfect, starts right away and under normal driving is great but it goes extremely lean at full throttle. Wideband will show 18:1 or worse and i obviously have to let off. Its now behaving perfectly, except at full throttle where it goes way lean. Amy ideas? Quote Link to comment Share on other sites More sharing options...
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