JhnRX7 Posted October 26, 2008 Share Posted October 26, 2008 A couple weeks ago while I was driving the 280zx it all of a sudden would not accelerate. It would idle fine, but the moment I would press on the gas to accelerate it falls on its face and sputters, backfires, and hesitates. No matter what I tried, it would not accelerate. Keep in mind that this occurred after about 30 miles of driving. After I parked the car and let it cool down for a while it would go back to normal and drive fine. Prior to this happening (about 500-600 miles) I had replaced the Fuel Filter, Distributor Cap, and Rotor. I figured that the problem was my fuel pump going bad because when it happened the car was getting a little hotter than usual and i only had about 1/4 tank of gas. I thought it was the fuel pump overheating and showing early signs of failure. I purchased a used fuel pump from a forum member here and threw it on... Sure enough problem came back yesterday after driving for an extended period of time! This time I noticed that it happened as soon as the water temp hit 180 degrees (aftermarket water temp gauge). Also this time I made sure to check the fuel pressure while the problem was happening and the fuel pressure was fine. And this time, as soon as the temp dropped below 180 degrees the problem went away. Sorry for the long post. Does anyone have idea what might be causing this? One of the temperature sensors or the ECU? Thanks, John Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted October 26, 2008 Share Posted October 26, 2008 Pull as many connectors apart as you can and look for corrosion (like maf or tps etc). I guess first thing I'd try would be the cylinder head temp sensor after that. If it keeps running but won't accelerate it probably isn't related to the sparking system (which sometimes fail due to heat). So something failing when she gets hot which kind of points to electronic gizmos. fuel pump wouldn't fail from engine heating up as it is out in the air by the rear wheels. Could be fuel vaporization but that would be way out there cause. CHTS was like $30 from napa not long ago as I remember. Quote Link to comment Share on other sites More sharing options...
woldson Posted October 27, 2008 Share Posted October 27, 2008 Do you have an electric fan? Also when cleaning stuff, pull and clean both sensors on the thermastat housing. Quote Link to comment Share on other sites More sharing options...
JhnRX7 Posted October 27, 2008 Author Share Posted October 27, 2008 After reading through the Workshop manual and Fuel Injection Bible, I have a feeling it has something to do with the Water Temperature Switch because it is directly connected to the distributor. The other good possibility, as roger said, would be the Cylinder Head Temp Sensor. I am going to go out right now and clean those two connections, plus all the other sensors on the thermostat housing and see if that helps. If not I am going to have to pull each sensor and manually test them. The cylinder head sensor is $46 alone, so I dont want to start arbitrarily replacing sensors. Although I do have one lying around and have thought about it, I dont have an electric fan installed. Thank you both for your help so far. I will clean the connectors right now, and post tomorrow if it made any difference. Quote Link to comment Share on other sites More sharing options...
tpnorth Posted October 28, 2008 Share Posted October 28, 2008 Hey after reading your post it sounds like i maybe having the same problem. My question is do you see any radiator fluid anywhere like leaking or something?? Quote Link to comment Share on other sites More sharing options...
roger.svoboda Posted October 28, 2008 Share Posted October 28, 2008 Change the chts it is cheap insurance and often affects the engine performance. Who quoted you on the chts? ask around a couple places I'm pretty sure I paid $30-35 about 6-7 months ago. Believe it was napa course prices kinda rising fast these days but that chts makes for bad juju when not working correctly. At a minimum pull it out put the ohmeter on it clean the connector really good look for busted wires what have you. Quote Link to comment Share on other sites More sharing options...
Hyuri Posted October 28, 2008 Share Posted October 28, 2008 Not wanting to spend the money for a replacement, I cleaned off the business end of my CHTS with some fine sandpaper (scotch pad would probably have been better) and it's been working fine for a couple of months now. Er, by business end I mean the end that contacts the head. You'll have to pull the sensor out to do that part (I think it was a 17mm wrench?). Quote Link to comment Share on other sites More sharing options...
JhnRX7 Posted October 28, 2008 Author Share Posted October 28, 2008 tpnorth: no fluid leaks that I am aware of. Roger: the quote was from MSA. MSA only had the chts, but no other temp sensors for the '83. Does anyone know of any other good place to get sensors? Napa? Online? Quote Link to comment Share on other sites More sharing options...
JhnRX7 Posted October 28, 2008 Author Share Posted October 28, 2008 also, I went out last night and cleaned the connections to the sensors. Most of them looked good, all except for the temp gauge sensor which was corroded. While I was there I checked the resistance from the negative terminal to the engine block and got a bad reading so I cleaned all of the ground connections. It runs MUCH smoother now. However it was too cold this morning to get it up to 180 so I was unable to see if I fixed anything. When I get home I'll drive it around the block with the AC on and try and force it to warm up. Quote Link to comment Share on other sites More sharing options...
Hyuri Posted October 28, 2008 Share Posted October 28, 2008 Oh yeah, bad grounds will definitely screw things up. If one was bad, I'd poke around and check resistance on all your grounds just in case. They're pretty easy to get to anyway. Quote Link to comment Share on other sites More sharing options...
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