Guest natepriest Posted July 19, 2008 Share Posted July 19, 2008 So I own a 1979 280zx that I'm trying to diagonse. It has recently had the following checked/replaced if needed; spark plugs, plug wires, distributor cap, rotar, fuel filter, fuel pump, valve cover gasket and a compression check. I just put MSA performance exhaust on hoping it would at least take care of an obvious exhaust leak, but I still notice it. I need to figure out if the leak is from something I did or preexisting, and besides that it still seems to be running weird. I ordered a cold air intake which I should get wednesday and I plan to get a header and maybe new throttle body with my next paycheck. It sat for a long time and before I got it back it would intermitently regain power as it climbed in RPM's and that power jump has become more and more seldom. It feels like a timing thing which I plan to check ASAP (although I don't know very much about fixing this stuff). I think I have a Chilton's or something for it around, but if I don't I was wondering if anybody knew where I could find out what my timing needs to be set to. And if anybody has any other ideas as to what might be robbing my car of its full performance I would appreciate any suggestions. Thanks a lot to anybody that had the patience to read this whole thing and possibly even post some advice. Nate Quote Link to comment Share on other sites More sharing options...
woldson Posted July 20, 2008 Share Posted July 20, 2008 Do your self a favor and search for efi bible. It is now even a sticky. Mine dose the same thing periodicly. For me it is the afm. I just leave the cap off and readjust it periodicly when it is needed. When your air fuel is off you will smell the bad combution easily. Also check the rear of the car around the muffler, my 82 had rotten away causeing fumes to enter the cabin. As for the afm adjusting, if you have the money get a wideband. I don't have one so it's kinda like peeing in the wind, but I always get it close. Quote Link to comment Share on other sites More sharing options...
Guest datsun 280zx turbo Posted July 20, 2008 Share Posted July 20, 2008 Use a timing light to check your timing marks on the crankshaft pulley/damper. There should be a sticker under the hood that will tell you what to set it at. I'm "guessing" your timing is ok, but still check it. I just fixed my 280 by disconnecting the fuel injection wiring harness and all the temp. sensors when i removed the head to replace the head gasket. I put everything back together and it now runs perfectly. No stumbles, just smooth power. Before that the car never really ran right. It built power slowly, chugged, popped and started hard, most of which I've attributed to bad wiring connecters. Give that a shot but really watch the connecters, they get fragile. Have you checked to make sure your air filter isn't clogged? Also I've heard if your AFM is bad your car wont start. Good luck, let us know how you make out. Quote Link to comment Share on other sites More sharing options...
freakshow Posted July 26, 2008 Share Posted July 26, 2008 when i bought my zx it had an obvious exhaust leak, it was loudest right under the hood, turns out a stud had broke off the exhaust manifold and the gasket had been eaten away by the exhaust gasses. I bought the car from a guy that didnt really know anything about cars, and had been driving the car like that for a couple of years, ended up having to get the manifold milled down because the front port had been corroded/eroded by the exhausr gasses. big pain in the ass. got the car back together now, and it doesnt seem to have a burnt valve, but it think i got lucky there. if the sound i louder out from under the hood than anywhere else, make sure you check the underhood gaskets too, save you some headwork. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.