Guest FutureMan280Z Posted December 11, 2007 Share Posted December 11, 2007 Hey guys I just joined up because I just traded for my first Z yesterday...So far I like it but Id like it even more if I could drive it... So I need some help troubleshooting my fuel problem, I finally got it to fire up today and It idles high (about 2000RPMS) and spit, spudders, and shoots flames when I rev it as well as pours black smoke at any RPM...Im hoping its just the air flow meter but I dont want to order one and it be something else...Any idea of what my problem could be, I know the AFM has been messed with because the side cover is off of it and I can see the internals. Blocked off the fuel line to the cold start valve this morning and it ran worse and my fuel pump is wired to a switch so I got it running(still very rough) and I turned the fuel pump off and it ran little smoother until it ran out of gas.... Quote Link to comment Share on other sites More sharing options...
MJLamberson Posted December 11, 2007 Share Posted December 11, 2007 read the fuel injection bible Quote Link to comment Share on other sites More sharing options...
chrism Posted December 11, 2007 Share Posted December 11, 2007 Try checking your fuel pressure. It could be high. Quote Link to comment Share on other sites More sharing options...
Guest FutureMan280Z Posted December 12, 2007 Share Posted December 12, 2007 Where do I find the fuel injection bible???? Quote Link to comment Share on other sites More sharing options...
Thumper Posted December 12, 2007 Share Posted December 12, 2007 It could also be your coolant temp sensor. If it doesn't read it thinks its -40 out and gives it alot of fuel. Here are alot good links on the z good luck. Oh BTW get a manual. http://www.msu.edu/~levesqu6/links.htm Quote Link to comment Share on other sites More sharing options...
Guest FutureMan280Z Posted December 12, 2007 Share Posted December 12, 2007 Looks like someone routed the fuel filter wrong, the filter is in the return line and the incoming line from the pump is free flowing, would that possibly raise fuel pressure??? Quote Link to comment Share on other sites More sharing options...
Thumper Posted December 12, 2007 Share Posted December 12, 2007 Looks like someone routed the fuel filter wrong, the filter is in the return line and the incoming line from the pump is free flowing, would that possibly raise fuel pressure??? Yes it would raise fuel pressure if the filter is more restrictive than the fuel pressure regulator. Take it out and find out. Quote Link to comment Share on other sites More sharing options...
Guest FutureMan280Z Posted December 13, 2007 Share Posted December 13, 2007 I threw some new plugs in today and it fired up and ran pretty good(still running rich) so I took it down the road and the hotter it got the richer it ran??? When it was cold I could rev it out to redline with ease and after it warmed up it would barely run and it was POURING black smoke Quote Link to comment Share on other sites More sharing options...
Larry Mahanor Posted January 15, 2008 Share Posted January 15, 2008 Hello Futureman: I've seen this problem many times, as I was once in the business of servicing the old Z's. The problem is most likely in the coolant temp. sensor circuit, and most, most likely the bullet connectors on top of intake manifold that goes to the sensor. They get corroded and old and don't make good contact. Also check the connector at the sensor itself. The sensor is mounted in the thermostat housing at the front of the engine. Outside chance it's a defective sensor itself. Follow the wires that go from the sensor up into the harness on top and you will find the bullet connectors. When the electrical connection to the sensor is weak, or the sensor is bad, it tells the ECU that the engine is cold and it dumps a lot of fuel into the engine. It can get so bad you'll fowl the plugs so they're sooty black. You'll need a fresh set of plugs after you fix the problem. Good luck! Larry Mahanor (Stickshift) Quote Link to comment Share on other sites More sharing options...
SR_man_49 Posted February 1, 2008 Share Posted February 1, 2008 also make sure your head temp sensor is connected. it should be above the 5th spark plug. Make sure the wires arn't corroded and it has a good connection. Quote Link to comment Share on other sites More sharing options...
Pyro Posted February 1, 2008 Share Posted February 1, 2008 no, this is not a zx. no head temp sensor at the #5 plug. the temp sensor is near the T-stat housing facing the radiator. Check the ohms on the sensor and the connection at the plug. The plug looks like an fuel injection connector (2 prong). Quote Link to comment Share on other sites More sharing options...
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