Nightscraper Posted November 14, 2011 Share #1 Posted November 14, 2011 I have been looking for the screw parameters but have been unable to find a thing. The car is running rich and we have checked everything and we need to give this a try. Anyone have any info on this? thanks! Link to comment Share on other sites More sharing options...
cozye Posted November 15, 2011 Share #2 Posted November 15, 2011 The 280 doesn't have an maf. It has an air flow meter that is not adjustable. Unless the AFM is broken, or someone has cracked the case and messed with the calibration it is not likely the issue. Download the fsm and perform a full efi diagnostic. Common sources for running rich will be the water temp sensor, fuel pressure regulator, cold start injector/thermotime switch. If full system check yields passing results you can follow blues tech tips page to recalibrate the AFM, if someone has messed with it before. Link to comment Share on other sites More sharing options...
Zed Head Posted November 15, 2011 Share #3 Posted November 15, 2011 There is one adjustment - the idle air screw. Maybe that's what you meant by screw? It will affect your CO and hydrocarbon readings. Turning it out leans the idle mixture. I've seen somewhere out there that five turns out from all the way in is a good starting point. It's supposed to set using a gas analyzer. Does it run rich all the time or are you just trying to pass emissions? Link to comment Share on other sites More sharing options...
FastWoman Posted November 15, 2011 Share #4 Posted November 15, 2011 To be truthful, there are a few adjustments on the AFM, but they're not meant to be adjusted. That doesn't mean someone hasen't adjusted them. Go to the Atlantic Z website (google it), and visit their tech tips (?) section. You'll find articles there about checking/adjusting the AFM. Before you do that, though, check your coolant temperature sensor circuit. If the sensor is bad, or if the connection to it is bad, your engine can run SUPER-rich, with black smoke out the exhaust. The best place to check this circuit is at the big connector to the ECU, behind the driver-side kick panel. This measurement and many others are described in Nissan's Factory Service Manual for your year/model, which can be downloaded for free from www.xenons30.com. BTW, welcome! Link to comment Share on other sites More sharing options...
TomoHawk Posted November 16, 2011 Share #5 Posted November 16, 2011 (edited) Sarah means you should go here for research: http://atlanticz.ca/zclub/techtips/EFI&fuel.htmYou can also find the EPROM chip program parameters there, so you can program the ECU. Edited November 16, 2011 by TomoHawk Link to comment Share on other sites More sharing options...
cozye Posted November 16, 2011 Share #6 Posted November 16, 2011 There is no EPROM chip to program Link to comment Share on other sites More sharing options...
sblake01 Posted November 16, 2011 Share #7 Posted November 16, 2011 I think (?) he was being facetious...... Link to comment Share on other sites More sharing options...
TomoHawk Posted November 16, 2011 Share #8 Posted November 16, 2011 Correct. Link to comment Share on other sites More sharing options...
FastWoman Posted November 16, 2011 Share #9 Posted November 16, 2011 Someone, somewhere, hacked an ECU and described how all the resistor values affect the injector pulse. I suppose an ECU could be tweaked that way, but the easiest way is simply to tweak the CTS circuit resistance. We'll tell you how to do that if it becomess necessary Link to comment Share on other sites More sharing options...
sblake01 Posted November 16, 2011 Share #10 Posted November 16, 2011 Someone, somewhere, hacked an ECU and described how all the resistor values affect the injector pulse. I suppose an ECU could be tweaked that way,....Imagine how trial and error/hit and miss/time consuming/tedious that would be to do with an anlog circuit board....... Link to comment Share on other sites More sharing options...
ZCurves Posted November 16, 2011 Share #11 Posted November 16, 2011 (edited) I agree with FastWoman.You can download the Fuel Injection Bible from the Members\Downloads section of this forum.If you are looking for a copy of the '78 FSM, here is a link to mine: http://www.mediafire.com/?y2x2e66oh939z9t Edited November 16, 2011 by ZCurves Link to comment Share on other sites More sharing options...
FastWoman Posted November 16, 2011 Share #12 Posted November 16, 2011 Imagine how trial and error/hit and miss/time consuming/tedious that would be to do with an anlog circuit board....... He actually hooked up the thing on an electronic test bench, so it wasn't a HORRIBLY time consuming thing. That said, I bet it did take a while. Link to comment Share on other sites More sharing options...
Patcon
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