Jt.drummer7 Posted August 22, 2014 Share Posted August 22, 2014 Hey guys! I've looked everywhere before posting this and haven't found anything like the problems I'm having here or on a few other sites. I bought a pretty much stock 1978 280Z a couple months back as a project car and have constantly had these issues and have never been able to find the culprit. Basically when I try to let it idle it will drop to 500 RPM sit there for a few seconds then die, but if I keep on the throttle it will stay alive and run pretty good going through the rev range although at anywhere between 3,000-4,000 when you let off it backfires. Now my other issue is when driving it will suddenly lose power and it will either come back after a bit or the RPM will start bouncing and it will just sputter and die, then after a few minute it will start right up and run strong for a bit. Or when starting out there is barely any acceleration until around 3,000 then it will pick up and pull hard. Although recently it just has barely any acceleration whatsoever. it's just dead no matter where in the rev range or which gear. Almost always when this happens there's a popping that sounds like backfiring but is actually the AFM which gets stuck at say half open when it should be all the way then it pops and goes back to normal and power will return for a bit after that. My personal thoughts are the AFM is bad seeing as how the car sat out and the AFM didn't have that plastic cover on it. Although the wiring could be part of the problem seeing as how all the fuel injector and sensor connectors are pretty much falling apart from dry rot. What do you guys think it could be? Thanks in advance! Quote Link to comment Share on other sites More sharing options...
NewZed Posted August 22, 2014 Share Posted August 22, 2014 Low fuel pressure comes to mind. Quote Link to comment Share on other sites More sharing options...
Jt.drummer7 Posted August 22, 2014 Author Share Posted August 22, 2014 I haven't had access to a fuel pressure gauge so I haven't been able to check that. But when I get the chance I will. I had my AFM looked at and it was confirmed bad. He said I should replace both of the boots to and from it as well since they're cracked. Also am going to splice on new connectors for everything and see if that helps. Quote Link to comment Share on other sites More sharing options...
ISPKI Posted August 24, 2014 Share Posted August 24, 2014 (edited) What was wrong with the AFM? Did you/he do a resistance test on all the pins? AFMs can be expensive, try testing it and fuel pressure before buying new parts. If the boot after the AFM is cracked open, then it could cause problems, maybe not what you are describing though. Also - There is a fella on here who sells harness plug kits for our system. His kit is very good, the plugs are top notch, sealed with little silicon grommets etc. I will try and find his user ID. Edited August 24, 2014 by ISPKI Quote Link to comment Share on other sites More sharing options...
ISPKI Posted August 24, 2014 Share Posted August 24, 2014 His name is FricFrac. Not sure if he still sells the kits but you should shoot him a message if you plan on replacing the electrical connectors. Quote Link to comment Share on other sites More sharing options...
nismosilvia Posted September 11, 2014 Share Posted September 11, 2014 I bet you have a clogged fuel filter. Brap Quote Link to comment Share on other sites More sharing options...
Jt.drummer7 Posted September 12, 2014 Author Share Posted September 12, 2014 I haven't checked that but it very well could have something to do with it. I noticed that right before it dies the voltage dips. Could this mean an electrical problem? Quote Link to comment Share on other sites More sharing options...
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