Zmanj87 Posted January 6, 2013 Share Posted January 6, 2013 So I just installed a new AFM plug since the old one needed to be replaced. Start up the car and it starts up fine but the Idle seems to be high and the needle doesn't stay steady. I noticed before I changed the plug but it starts at 1000 rpms and the needle just bounce between 1000-1500 rpms. So could it be a vaccum leak or maybe a bad AFM? Quote Link to comment Share on other sites More sharing options...
BluDestiny Posted January 7, 2013 Share Posted January 7, 2013 Sounds like a vacuum leak from cracked rubber somewhere. I would check around the AFM first since that's what you were messing around with. Quote Link to comment Share on other sites More sharing options...
Zmanj87 Posted January 7, 2013 Author Share Posted January 7, 2013 ya I'll check now it's idling fine at 1000 rpm's but it shuts off on me when I put it in 1st gear and then eas up on the clutch. If I push on the gas I get no response it just shuts off. The wiring job I matched up all the same wires and spliced them together then put some solder on each connection. After that I put heat shrink on each one to weather seal it.,,, Before I replaced the plug it didn't do this as bad it had a frayed connection that's why I replaced it. Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 7, 2013 Share Posted January 7, 2013 Sounds like you might be running lean because the ECU isn't connected to the AFM. You'll have idle fuel but no fuel from the AFM vane which will raise your idle a little. When you open the throttle it goes way lean and dies. Checking the pins at the ECU might be the easiest, quickest way to confirm. The 100 and 180 ohm measurements are the important ones, for a 280Z. Pins 6, 8 and 9 I believe, it's in the FSM, just measure actual values at the ECU connector pins instead of continuity. ECU pin numbers match the AFM pin numbers. Quote Link to comment Share on other sites More sharing options...
Zmanj87 Posted January 7, 2013 Author Share Posted January 7, 2013 Ill check that out as well thanks zed. Just to note the car ran fine before I replaced it. Reason I swapped the plug was because the old one was had a loss connector in the plug and would cause the car to hiccup . So could it be a bad wiring job on my part? Quote Link to comment Share on other sites More sharing options...
motomanmike Posted January 7, 2013 Share Posted January 7, 2013 Anything is possible. As its wired currently if you jiggle the wires or new plug whiles its running is there any change in the way it runs? By any chance did your grounding points change when you moved it for repair? I know there are a few grounds that terminate there and they are VERY important. Quote Link to comment Share on other sites More sharing options...
Zmanj87 Posted January 7, 2013 Author Share Posted January 7, 2013 I'll try jiggling the wires and seeing but as for grounding no they did no the only wire I took off that was grounded was the one thats connected to the AFM mounting plate thats seem to be for another part near the AFM and I put that right back where it went. It sits and idles fine like I said when I try to start driving it thats when It acts up. I think Zed is right and its running lean because the ECU isn't registering the afm. I ordered a volt meter and will post my results wednesday. Is there a useful reference on how to test the ECU connectors and what readings I should be getting? Quote Link to comment Share on other sites More sharing options...
Zmanj87 Posted January 10, 2013 Author Share Posted January 10, 2013 Update: So I redid the wiring and actually used the Wiregraph and also realized the Pin number are actually on the wire harness... and she started up and ran fine!! Took it around the block a couple times and had no problems in different gears! Thanks again for everyone help with this problem and I'm sure I'll be back with more questions! Quote Link to comment Share on other sites More sharing options...
Fourstring Posted February 25, 2022 Share Posted February 25, 2022 I'm having this same issue with my 75'. You mentioned using the Wiregrass, would you happen to still have a link or the information on hand, I know it's a stretch. I appreciate any help. Quote Link to comment Share on other sites More sharing options...
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