hchase17 Posted April 28, 2009 Share Posted April 28, 2009 83 turbo is misfiring. It's worst when I first start the car, and it gets better as I run. It misfires/backfires a little when I let out of the throttle. And it doesn't just seem to do it in any pattern its just random. I was thinking possibly the fuel pump but I dont know. Does anyone have any suggestions. Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted April 28, 2009 Share Posted April 28, 2009 open up the driver side kick panel and push on the middle connector on the ECU. Quote Link to comment Share on other sites More sharing options...
hchase17 Posted May 2, 2009 Author Share Posted May 2, 2009 didn't do anything still the same Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted May 2, 2009 Share Posted May 2, 2009 misfire be likely in the ignition system not the fuel system. If the fuel pump no fuel and she just bogs down. FPR bad too much fuel and runs rich or if fail the other way no fuel and again bogs down. I'd look at coil, dizzy, dizzy cap, plug wires. Loose connections someplace. Quote Link to comment Share on other sites More sharing options...
hchase17 Posted May 3, 2009 Author Share Posted May 3, 2009 cap, rotor, plugs, and wires all new. I may need to clean the connections. It does sound as if its running lean though. Another thing ive noticed since i posted is that it runs much worse when under 1/4 tank. The coil isn't the problem because I had temporarily replaced it with a new one but returned it cuz it ran exactly the same. I replaced both collant temp sensors also. Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted May 3, 2009 Share Posted May 3, 2009 Hook up a fuel pressure gauge and check for the pressure when the problem occurs. Let me see I can find my logs for this problem on my web site. Here is it is from my old web site. "Complete the intercooler pipings. Got the "vacuum control valve" from Dustin and hook it up. Also got the T5 drive shaft from Dustin and installed it. Fill up all the fluids and attempt to start it up. Check sparks and it's Ok. Check fuel and it's pumps OK. Start it up and it runs for a few seconds and dies. After a few hours with no luck I hook up the fuel pressure gauge to check for pressure. The pressure was too low. Open up the fuel line before the fuel pump and blow air thru it. Now it has fuel pressure. Start it up and no good again. Lots of smoke .. running rich.. Replace AFM with a new one and it fires up .. YESSSSSSSs.. Let it runs and warm up and set the timing and adjust idle speed. Take it around the block and it seems like it is not running smooth at WOT. Hook up the A/F mixture meter and boost gauge. Look like it's running lean at a certain spot and bogged. Suspect a loose connection at the computer or bad fuel or something. I still have to think about this problem and how to attack it. 5/6/03 - Solved the running lean problem. It was the fuel sending unit inside the tank. There is a small filter at the end of the supply line going to the pump. This filter has build up a thin layer of film on it and limiting fuel going to the line. Also the line was half clogged. I clean both of them up and hook it back up and the car runs strong under boost." and this "Also found out that the car still running lean under boost. Found out that the computer plugs are not making good contact. Clean it real good and put some conductive grease to all the pins and looks like the problem is solved for a short time. I finally went to a junkyard and cut up some computer plugs from a 300ZX and splice them into my 280ZXT and it seems no more problems now." GL Quote Link to comment Share on other sites More sharing options...
hchase17 Posted May 4, 2009 Author Share Posted May 4, 2009 so i cleaned out the fuel tank p/u lines and it runs a little better. It is smooth on decel no except for a small pop when i first let out of the accelerator and it has a misfire when I first get onto the accelerator. The car is still bad on cold starts for just maybe 5 minutes or so then its fine. I also noticed a small popping noise when i was listening under the hood coming from the 6th cylinder. It does this at idle and at any constant speeds but not in accel or decel. Maybe an injector? or not the right gap on plug? Quote Link to comment Share on other sites More sharing options...
jayzrocket Posted May 7, 2009 Share Posted May 7, 2009 If you havent already, check the cylinder head temp sensor connection or even the sensor. This gave me the exact same issue. If you relace it try and get a nissan one, I've had better luck with the factory electrical parts. Also don't over tighten when replacing it so that it doesn't bottom out and get dammaged. This is located on the passenger side of the cylinder head by the back two spark plugs and the connector resembles the fuel injector connectors type. Quote Link to comment Share on other sites More sharing options...
hchase17 Posted May 10, 2009 Author Share Posted May 10, 2009 already replaced both temp sensors...head and thermostat housing...im gonna check out the afm in the morning Quote Link to comment Share on other sites More sharing options...
280zxmike Posted May 14, 2009 Share Posted May 14, 2009 you could also try the tps mine gave me problems for a while, and its a cheap fix Quote Link to comment Share on other sites More sharing options...
thetremendoustim Posted July 16, 2009 Share Posted July 16, 2009 was this ever resolved? Quote Link to comment Share on other sites More sharing options...
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