Ga_Z Posted April 17, 2009 Share Posted April 17, 2009 My '76 280 sat for years and not too long ago I got it running. It idles OK but when you give it gas it backfires through the manifold and leans out. The a/f ratio shoots up to 45 and it bogs down. I downloaded the FI bible from a link I found on here and ran all the tests, it failed 2, both having to do with the AFM. I have way too much resistance on my readings. I took off the AFM and opened it up, when testing the resistor or wiper or whatever you call it, it starts building ohms smoothly but then shoots from around 74 to 290. I can see wear marks that almost look like cuts on the wiper it runs against. I guess my question is can this be repaired? Or am I looking at having to buy another AFM. Any ideas would be appreciated. Quote Link to comment Share on other sites More sharing options...
RUZN Posted April 17, 2009 Share Posted April 17, 2009 Will my 280zxt 1981 AFM work for your car? prolly the same eh? If you want it I'll sell it cheap to ya as I switched to MAF =-) let me know Quote Link to comment Share on other sites More sharing options...
azcarbum Posted April 17, 2009 Share Posted April 17, 2009 No... You will need to find a AFM from a 75-76 Quote Link to comment Share on other sites More sharing options...
RUZN Posted April 17, 2009 Share Posted April 17, 2009 What about if I gave him my 1981 N/A ECU =-) Quote Link to comment Share on other sites More sharing options...
azcarbum Posted April 17, 2009 Share Posted April 17, 2009 nope Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted April 17, 2009 Administrators Share Posted April 17, 2009 The reason for the earlier AFM is because the early cars have a switch in the AFM itself that controls the fuel pump. The newer AFM's that switch was deleted and that switch became integral in the oil pressure sender, (safety reasons for say if you got in accident, the car flipped over and the engine died due to oil starvation etc, the fuel pump wouldn’t continue to pump gas feeding a possible fire!) In short, if you install a newer AFM in an older car, the fuel pump wont even turn on other while cranking. Of course you could by pass that and manually control the fuel pump but you wouldn’t have that built in safety feature, i.e. I do not recommend or condone that you by pass or alter the built in safety measure of the fuel pump control. Quote Link to comment Share on other sites More sharing options...
Ga_Z Posted April 18, 2009 Author Share Posted April 18, 2009 So can I repair this thing or is it toast? Quote Link to comment Share on other sites More sharing options...
Challenger Posted April 18, 2009 Share Posted April 18, 2009 To be honest just find an afm in the for sale section. Im sure someone would be willing to give you a good deal. Could this be partially related to your cam? Just a suggestion. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted April 18, 2009 Administrators Share Posted April 18, 2009 (edited) Sometimes, you can loosen up the grid that holds the wiping surface and shift it far enough the wipers are wiping on a fresh surface area and that will "sometimes" fix an erratic AFM. It doesn't really have much movement, but some times just enough... Another trick for emergency use on an AFM that is known bad (I do not condone this method on a good AFM as I am not aware of the long term affects of this procedure), electrical contact cleaner or 99% rubbing alcohol on a cotton swab brushed lightly across the offending section of the wiping surface may help as well. Beng as it is arledy toast, those options are cheaprer than another AFM and probably worth the effort in case it gets you a few more months driving... Edited April 18, 2009 by BRAAP Quote Link to comment Share on other sites More sharing options...
Ga_Z Posted April 18, 2009 Author Share Posted April 18, 2009 I actually tried moving the grid but it didn't help. I'll try the alcohol and see if that works. I may have to wait until Monday, we have 99% at work. Thanks for the tip. Quote Link to comment Share on other sites More sharing options...
Ga_Z Posted April 26, 2009 Author Share Posted April 26, 2009 Would an AFM from a '78 work on my car or do I need one from a '76??? I founda nice one I may be able to get but it is from a '78. Quote Link to comment Share on other sites More sharing options...
trippintl0 Posted April 26, 2009 Share Posted April 26, 2009 (edited) Why don't you watch this video tutorial. I found this a few months back. Edited April 26, 2009 by trippintl0 forgot link Quote Link to comment Share on other sites More sharing options...
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