280zedx Posted July 1, 2004 Share Posted July 1, 2004 I'm getting near my wits end! It fires up like a champ then dies. It took a while but i found my lack of any tach signal was due to the tach pin in the relay box to MS harness being out by one at one end - doh! Still no signal, just a few ticks that shows that it's connected. That was eventually found to be the IC module (little black box on the side of the distributor) failing. arghh! It worked fine just before the megasquirt swap. I've put the "spark" part of MS&S on hold for now until i can get it running. Just the stock N/A distributor (not the CAS style). The GM HEI directly off my pick-up coil didn't seem to work but i seem to get a good signal now with a new (used) same stock IC module. Everything has been multichecked and appear to be working perfectly. Dead on timing. Good spark to all plugs. all good sensor readings. Stock L28 turbo req fuel and constant settings etc. The priming pulses obviously work and it fires right up but then dies right away. I'm borrowing a fuel pressure gauge this weekend and also will buy a set of injector test noads to verify that all injectors are getting a good signal. The turbo (259cc) injectors are the only other variable thats changed since it was running last. (and they are suspect since i didn't get them tested or cleaned) As far as tach signal quality, what are the symptoms? A friend's of mine's got an oscilloscope, what kind of data or waves should i be looking for? It sure sounds good for the 2 seconds at a time i can get it running! Has anybody else had this "simple" problem? It's tough being so close and so frustrated... Mike '83 - 280zx Quote Link to comment Share on other sites More sharing options...
Tim240z Posted July 1, 2004 Share Posted July 1, 2004 http://www.msefi.com/index.php try here? Quote Link to comment Share on other sites More sharing options...
jkube Posted July 1, 2004 Share Posted July 1, 2004 Mike I had same problem with my MS when trying to get it setup. Your enrichment settings need some correcting, the car isnt getting any fuel after initial cranking It sounds like you have the "cranking pulsewidths" close because the car fires instantly, check your "afterstart enrichment" settings. You might want to increase the enrichment %. Increase this number until the car keeps running. A fuel pressure gage will come in handy to make sure you have correct pressure. I've been finding that some of my problems were from pressures too low and too high. But I been finding that if the pressures are close to stock ( 30 -40 PSI ) the will start. It just may not drive well Also if the car is hard to start, double check a couple of spark plugs to see if there is too much fuel (or not enough), then adjust the cranking pulse width % and after start enrichment % until you can get the car started and running. If the plugs are wet lower the % numbers and if they are dry then increase the % numbers. Keep a spare set of plugs handy too. If you flood the motor, change the plugs right away, otherwise the car will either not start at all or run like #$!@@#. You can then dry out the plugs later with fuel injection cleaner spray and use them again later Hope this helps Jeff 72 240z, L28 N/A with Fuel injection and MS, Walbro 255 lt/hr pump, Aeromotive pressure regulator, Turbo injectors. Quote Link to comment Share on other sites More sharing options...
jkube Posted July 1, 2004 Share Posted July 1, 2004 Mike I had same problem with my MS when trying to get it setup. Your enrichment settings need some correcting, the car isnt getting any fuel after initial cranking It sounds like you have the "cranking pulsewidths" close because the car fires instantly, check your "afterstart enrichment" settings. You might want to increase the enrichment %. Increase this number until the car keeps running. A fuel pressure gage will come in handy to make sure you have correct pressure. I've been finding that some of my problems were from pressures too low and too high. But I been finding that if the pressures are close to stock ( 30 -40 PSI ) the will start. It just may not drive well Also if the car is hard to start, double check a couple of spark plugs to see if there is too much fuel (or not enough), then adjust the cranking pulse width % and after start enrichment % until you can get the car started and running. If the plugs are wet lower the % numbers and if they are dry then increase the % numbers. Keep a spare set of plugs handy too. If you flood the motor, change the plugs right away, otherwise the car will either not start at all or run like #$!@@#. You can then dry out the plugs later with fuel injection cleaner spray and use them again later Hope this helps Jeff 72 240z, L28 N/A with Fuel injection and MS, Walbro 255 lt/hr pump, Aeromotive pressure regulator, Turbo injectors. Quote Link to comment Share on other sites More sharing options...
sims76 Posted July 1, 2004 Share Posted July 1, 2004 Use this file: Datsun_280z_nonturbo_19lb_injectors.msq from the following page.... http://autos.groups.yahoo.com/group/megasquirt/files/Megatune%20settings/ This Megatune settings file is what I have used in my car and others on this board have had success with it also. You might want to give it a try or at least examine the startup values. Maybe you're not in the ballpark. Good luck, Sims Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted July 1, 2004 Share Posted July 1, 2004 Are you sure that the wiring is set up correctly to supply power to the coil AFTER cranking? I seem to recall that someone else had this problem - not necessarily w/MS... Quote Link to comment Share on other sites More sharing options...
280zedx Posted July 1, 2004 Author Share Posted July 1, 2004 (This Megatune settings file is ....) -Sims, the file you posted doesn't seem to open and can't be saved as a file either. Are these the N/A injector settings? I'll be trying to play with the enrichment settings some more today. thanks all, Mike Quote Link to comment Share on other sites More sharing options...
sims76 Posted July 1, 2004 Share Posted July 1, 2004 I fixed the link above. This is the file that I used for my car. I tuned it with a wideband O2 meter. Quote Link to comment Share on other sites More sharing options...
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