Guest Dubz Posted March 1, 2004 Share Posted March 1, 2004 Hello, I have just recently discoverd this great Z car site and I'm loving it . Lots of great info and plenty of inspration can be found on this site. Anyways to get to the topic at hand, I have a 75 280z that used to run good except for getting horrible gas milage (8-10MPG). One day the engine just felt week and shuttered while under acceleration and at idle. I checked for spark on all cylinders and sure enough the middle 2 cylinders (i think, it could be the 4th and 5th cylinders in from the front) are not fireing. They are getting spark though so I assume its a fuel problem. Anyone have any ideas about whats wrong and how I could go about fixing the problem? Thanks alot Quote Link to comment Share on other sites More sharing options...
A. G. Olphart Posted March 1, 2004 Share Posted March 1, 2004 Try a compression test... When adjacent cylinders die it may be the head gasket is blown between the two. Quote Link to comment Share on other sites More sharing options...
zguy95135 Posted March 1, 2004 Share Posted March 1, 2004 try checking the fuel injectors for those cylinders, but Im not sure how to do it right so ask someone first Quote Link to comment Share on other sites More sharing options...
Guest Dubz Posted March 3, 2004 Share Posted March 3, 2004 Try a compression test... When adjacent cylinders die it may be the head gasket is blown between the two. I'm dont think its the head gasket, when I pull the plugs out of the cylinders while the engine is still running there is absolutley no change in the idle. I would think that if these cylinders were just low on compression it would change the idle, at least a little. try checking the fuel injectors for those cylinders, but Im not sure how to do it right so ask someone first Ya I think thats my best bet, but has anyone ever heard of two fuel injectors just quitting at the same time? Also info on how to go about checking the injectors is welcomed Quote Link to comment Share on other sites More sharing options...
olie05 Posted April 29, 2004 Share Posted April 29, 2004 Have you pulled the valve cover off? When my old engine was running on 5 cylinders it was because the rocker arm on the head had fallen off. The cam wasn't opening the intake valve at all. It would be a coincidence that two adjacent cylinders would be doing this. Quote Link to comment Share on other sites More sharing options...
zxgts-4 Posted April 29, 2004 Share Posted April 29, 2004 Hey Dubz If you pulled the plugs "out" and it made no difference to idle quality I would say that is idicative of gasket problem, compression test before chasing an injector problem. Neil Quote Link to comment Share on other sites More sharing options...
datsunlover Posted April 30, 2004 Share Posted April 30, 2004 I had a 280zx that did the same thing. Turned out it WAS a bad injector. I to did the 'pull the plug out and run it' and it actually seamed to run BETTER. At the time I couldnt figure it out so I sold the car. The guy I sold it to, finaly figured it out. Changed ALL the injectors and it ran Grrrrreat! Check the injectors... heck, just to see what happens, you could swap the two that are giving you trouble with two other cylynders and see what happens.. Quote Link to comment Share on other sites More sharing options...
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