lifegrddude Posted July 13, 2005 Share Posted July 13, 2005 Hey everyone, I've gotta bit of a problem on hand with my Z. Here's some background on it: z31 ecu swap, Crane ignition system, new fuel filter, cap, rotor, plugs, etc. I drove to a friend's house and my Z was running perfectly fine. After we installed a push button starter/switch combo (as a theft deterrent), I can't get the Z to drive under load. It idles perfectly fine, but the moment it is moving and I give it any kind of throttle pressure, it sputters and practically dies. When I let off the gas, it idles fine again. I tried disconnecting the harness plugs a couple times, but that didn't work. I'm thinking it might be an actual wire to the harness since it ran fine before the push button installation... Any ideas which wire/wires it could be on the harness to the ecu? Or could it be something else? Thanks. Quote Link to comment Share on other sites More sharing options...
Guest Battle Pope Posted July 13, 2005 Share Posted July 13, 2005 My CRX did that when the fuel filters went bad. It would drive fine, but when I went to get on it it would choke and die. I could only think that fuel was getting through fine for idle and driving conditions, but when the engine required more fuel the filter was bottlenecking it too much. Quote Link to comment Share on other sites More sharing options...
lifegrddude Posted July 13, 2005 Author Share Posted July 13, 2005 I tried a new fuel filter, but it still sputters when giving it gas. I checked the fuel pressure, and it never changes, stays at a constant 28psi. I can't get the engine to rev over 2K rpm whether in neutral or while driving. I can't press the gas pedal down at all while driving or else it bucks and sputters. When the Z is in neutral, if I keep the gas floored to the 2K limiter, it will eventually die after misfiring for about 5-10 seconds. The ecu keeps varying the trouble code. On some occasions it will say a faulty crank sensor, and other times it will flash multiple codes such as maf and chts. I tried using a spare maf and ecu, but the problem remains. Does anyone know which pin on the z31 ecu is the one for the crank angle sensor and which pin is for the chts? I want to double check those wires' conditions. Thanks. Quote Link to comment Share on other sites More sharing options...
zdmz Posted July 14, 2005 Share Posted July 14, 2005 I thought this post was going to be about farting!!!! Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 14, 2005 Share Posted July 14, 2005 This symptom sounds like a problem with the AFM (stock EFI) and MAF with the Z31 EFI. Next thing I suggest is to check your TPS also. Good luck.. Quote Link to comment Share on other sites More sharing options...
v8dats Posted July 18, 2005 Share Posted July 18, 2005 i agree with the tps Quote Link to comment Share on other sites More sharing options...
lifegrddude Posted July 20, 2005 Author Share Posted July 20, 2005 I wish this were a post about farting! Anyways, thanks for the suggestions so far. I tried a different tps and it did not help the problem. It continues to idle perfectly fine, but as soon as I go to 2000rpm it keeps sputtering and under light throttle and will completely cut out if I floor the throttle. I redid the wiring to the ecu connectors and maf, I've tried two different ecus and a spare maf, but nothing has worked. I'm beginning to wonder if maybe it's the distributor or maybe a weak ignition module? Any thoughts? Thanks. Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted July 20, 2005 Share Posted July 20, 2005 lifegrddude, Sorry to hear you still having problems. My car does that when it is not completely warm up and even so if I floor it it will take off. Have you check your fuel pressure at the rail? Sputtering usually not having enough fuel either your ECU is not sending signal to the injectors or you have a fuel clog somewhere. When I trouble shoot my blue ZXT I had the fuel gauge hooked up and that's how I found out I had the fuel clog. I would suggest you to spend $20 to get one from Summit to save you the troubles. With the fuel gauge you can verify the FPR is OK and or your fuel pick up hose in the tank is not clog. If the fuel pressure checks out OK then I would go check the AFM. Make sure it sends the correct signal to the ECU. With the MAF I don't know how you will be able to do a unit test. With the AFM you can do that by measuring the resistence when moving the flap. Good luck V. Quote Link to comment Share on other sites More sharing options...
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