tclhenstra Posted July 7, 2007 Share Posted July 7, 2007 i'm a new owner of an 83 280zx l28et. it's a beast and i've got it running in no time. i had to drop the gas tank and pretty much clean the fuel system and strainer of syrup. that is left over seperated gasoline. anywho, she's been running fine as of late. but now i can't give her any gas or get up to a certain rpm before she starts sputtering out and popping. it sounds like she's burning rich when she pops but i don't see any black smoke behind me. it just pops. i'm wondering could the tps or mass air flow sensor be going out on it? or has anyone else had this problem? like i said she's old and the previous owner had her sitting in his back yard for a few years after she sat with the owner before that. anyways there's more than that but that's biggest problem, and i was hoping to get some seasoned advice since this was my first 280zx and 83. lol preciate any advice. Quote Link to comment Share on other sites More sharing options...
Administrators BRAAP Posted July 8, 2007 Administrators Share Posted July 8, 2007 I’d start with replacing the fuel filter. Sounds like it is starving of fuel, hence no smoke. Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 8, 2007 Author Share Posted July 8, 2007 sorry i should have said earlier. i've replaced: fuel filter, plugs, wires, and a few hoses plus the thermostat. as well as buil a custom short ram after the MAFS. i've been running injector cleaner to try and prevent any gunk from getting plugged in the injectors. but after like 2nd and late in 3rd gear the acceleration picks up pretty good. Quote Link to comment Share on other sites More sharing options...
nish Posted July 8, 2007 Share Posted July 8, 2007 I too was staving for fuel when I first resurrected my Z. Your poping is probably front firing in hte intake from going lean. I didn't start finding the problem until I put a fuel gauge under the hood and found I was running half pressure. This was after having the tank professionally cleaned and putting on a new fuel filter. So, what was the culprit? There is a screen in the inlet of the stock fuel pump that had collected a pile of rusty crap. I dug it out of there and my problems went away. I've been running that same original pump for the last 4 years. See if this applies to you. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 8, 2007 Share Posted July 8, 2007 This is also a classic symptom of the L28ET connector syndrome. Take the TPS, AFM, and ECU connectors, unplug them, spray with contact cleaner, grease with dielectric or silicone grease and reassemble. You will be amazed. There are about 100 threads about this. Hope it works for you. If it does, keep going. Do the injectors, and all the grounds and sensors you can find. South Carolina + Old connectors = trouble. Welcome to HybridZ! Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 8, 2007 Author Share Posted July 8, 2007 i cleaned the strainer in the fuel tank when i first resurected the car. i've sprayed most of the sensors, i'm sure i probably missed a few or something along those lines. these are a very helpful i'm gonna take a look at them all. preciate it fellers! i'll let you know how it works. Quote Link to comment Share on other sites More sharing options...
sweetleaf Posted July 8, 2007 Share Posted July 8, 2007 Sounds lean, I'd put a fuel pressure gauge on it. Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 8, 2007 Author Share Posted July 8, 2007 NO POWER TO THE TPS. not sure why.. any ideas? the egr was going bad but my buddy said to plate it off. pro's and con's? it's deff. lean because no black smoke with the spurts. are there any relays or fuses that the tps runs through for power? Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 8, 2007 Author Share Posted July 8, 2007 o yeah also there's only 2 wires to the sensor but the one i have, has 3 just a ground right? Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 9, 2007 Author Share Posted July 9, 2007 i put a new fuel pressure regulator on it, it ticks but so did the last one. the car runs great now. possible problems with the noise? also i'm assuming i have a bad valve in cylinder one. i've been told those are hydrolic lifters and i should pump them up to fix it, but i need to know definitively before i got messing with anything. i was planning on doing a valve adjustment anyways. Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 14, 2007 Author Share Posted July 14, 2007 it's been a while. could it be the turbo? also i've got a broblem with compression in 1. about 30. the rest are well in the 120+ psi range. not sure if it's intake or exhaust side either. sometimes you can hear it so i figure it's stuck. i'm planning on an overhaul of the motor soon anyways, cause of miles. i'll check then any sugestions to see how to fix the valves? Quote Link to comment Share on other sites More sharing options...
spacecase70 Posted July 14, 2007 Share Posted July 14, 2007 contact braap he could give you the advice on the head work! Quote Link to comment Share on other sites More sharing options...
rags Posted July 14, 2007 Share Posted July 14, 2007 Do you have access to a compressor? If so you can use it to figure out where the compression is going. You have to rig something to connect the air supply hose to the spark plug hole on the bad cylinder. The, with that cylinder at TDC of the compression stroke, introduce compressed air into the cylinder. You will be able to hear the air entering the crankcase through the valve cover breather if you have a ring, piston ring land, or head gasket problem, entering the intake manifold from the throttlebody if you have a burned intake valve, or entering the exhaust manifold from the turbo downpipe if you have a burned exhaust valve. Quote Link to comment Share on other sites More sharing options...
BleachZee Posted July 20, 2007 Share Posted July 20, 2007 When my turbo engine was poping out the intake (just as 2psi of boost came in) I checked a lot of things like was mentioned. In the end it was a boost leak. It could be any number of points on the intake. I found several. The cold start hoses were all new, but still with new clamps they leaked a little. I elimiated some, disconnected the carbon canister, and found that I had not properly installed the injector holders so the seals were leaking right at the manifold. Quote Link to comment Share on other sites More sharing options...
Careless Posted July 27, 2007 Share Posted July 27, 2007 What I would do is remove the fuel pump, and take off the top 4 screws, replace them with allen head bolts that have the same thread pattern, and can screw on tighter. replace the O-rings in there with suitable o rings. linish (lightly sand with fine paper) the drive gears in the pump to remove any crud off them, and clean the filter that is on the inside of the pump spout. THAT is where most of the ♥♥♥♥ stays. then before you put it back on the car, crank the engine over so it spits out all the fuel and there is no pressure in the lines. Remove the fuel rail and clean the pre-filter screens infront of the injectors, located where the hose plumbs into the top-feed of the injector. that should allow it to flow a bit more freely Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 29, 2007 Author Share Posted July 29, 2007 sounds good. i read the TPS have some major issues with these early zx models. could that be a culprit? because when i'm all the way on the throttle, the car hesitates and sputters but the instant i let off the gas a little bit. BAM acceleration. i would think boost eccept it gets worse as the rpm's get higher. also what is the easiest way to get hp out of these. i'm tossing up a rebuild or a swap. ideas, suggestions, or contidictions? all is welcome. just getting some general ideas about the capabilities and pro's and cons to a rebuild or swap. (not to an L series probably) so i really am interested. preciate the help and suggestions. tony Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 29, 2007 Share Posted July 29, 2007 Well here is a tidbit. Don't rip everything out and rebuild it without first identifying the problem clearly. You will be sorry if you rebuild it and end up with the same problems. Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 30, 2007 Author Share Posted July 30, 2007 Well here is a tidbit. Don't rip everything out and rebuild it without first identifying the problem clearly. You will be sorry if you rebuild it and end up with the same problems. is that a link to your car? if it is, DAMN! that things hot! if it's not, again damn she's hot. but i was looking at alot of things on that motor. the egr was delted. is that a comon thing on these engines. alot of things on the manifold were deleted is that beneficial to the motor or just cosmetic. but i got alot of inspiration from that site. most of that stuff i've just been trying to figure out myself and that really helped. be nice with a DIY thread. lol Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted July 30, 2007 Share Posted July 30, 2007 Yeah that's my car. Thanks. I am glad you enjoyed it. I deleted the stuff after using it all for a few years with the stock EFI. Once I went with MS, I didnt feel the need to use all the appendages on the intake manifold. Basically, once all the stuff was removed, there was NO difference in the way the car ran. Quote Link to comment Share on other sites More sharing options...
tclhenstra Posted July 30, 2007 Author Share Posted July 30, 2007 is that a 240 with the 280 in it? that's pretty much exactly how i want mines! lol same color and wheels. i'll have to get a little more original now though. what did you get rid of? i mean i see the breather cap on the valve cover and the vacuum llines from behind the throttle body. how hard was the fuel rail conversion? what cc injectors did you switch to? Quote Link to comment Share on other sites More sharing options...
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