Steveoen Posted April 25, 2011 Share Posted April 25, 2011 the car is a 1978 280z running a f454 block and p79 head it still uses a 78 distributer and everything else off the 78 motor except i am running a cylinder head temp sensor instead of a water temp sensor. now about a month ago the car was running fine until i was cruising around 50mph then the motor started to choke itself out starving for fuel so i pulled over it would idle rough and if you tried to rev it it would sut starve for fuel or misfire. I then replaced the coil and the next day it ran fine for about 5-10 miles then did the same thing this time it died after about 1 minute of starting to bog out so i then replaced the fuel pump and fuel filter (in the wendys parking lot i broke down in ha) then after getting gump started (guess which key doesn't work on my keyboard) i was able to drive it about 5 miles before it start to sputter and i broke down the next day i replaced the plug wire to the coil it started up idled fine drove it the rest of the night until the car gust shut off so i replaced the alternator then the next day it was driving fine for about 10-15 miles before all the lights dimmed out and it sputtered to a stop i rewired the alternator and now besides the fact its a bit smokey (probobly need a new head gasket) it runs fine except for after 3 thousand rpms the alternator charge light will come on and my ebrake light will flicker and the volts are reading 16+ things i have replaced coil coil wire fuel filter fuel pump alternator cylinder head temp sensor the ignition system is testing out fine and my thermotime switch is also reading fine any ideas what i should check? it idles and drives fine except for the odd electrical problem volts are 16+ on the gauge and the ebrake light will flutter while driving it was driving around neighborhoods fine and was idling at 900 steadily ust the electrical thing is making me nervous considering the amount of times i have broken down if you need anymore information let me know or have any ideas what i should test let me know and i will post the results thank you fore taking the time to read all of this and yes i have the efi bible and manual so dont tell me to go read those i have multiple times and done all those tests. still baffled any help would be appreciated Quote Link to comment Share on other sites More sharing options...
19762802+2 Posted April 25, 2011 Share Posted April 25, 2011 What do you mean by Cylinder head temp sensor? are you talking about the connector by the 5th and 6th spark plug? If thats what your using for your Head temp thats actually a Knock sensor and won't work as a Temp sensor at all. It also sounds like your charging system isn't work right and if that is out of order your Voltage won't be high enough and it will cause your EFI to act up. EFI is really specific with the voltage it gets, If its too low it won't run correctly and the car will sputter and die. It's possible your battery is bad and isn't charging up so that would be a good thing to get tested. Since you got a new alternator and it seems its still not working 100% correctly its possible that your Voltage regulator went out as well unless you did the 280zx internal regulated Alternator Swap. As for the Charging light coming on I can't say much about that as I don't really know but it seems you have an issue with wiring or something else. Your ebrake light is probably flickering because the connector under the carpet on the passenger side for your ebrake is probably coming loose or the little sensor is broke. The light is also connected to your brake line router near the brake master under the washer fluid reservoir. Quote Link to comment Share on other sites More sharing options...
Steveoen Posted April 25, 2011 Author Share Posted April 25, 2011 the battery tested right and thats not a knock sensor its a cylinder head temp sensor it told me that in the efi bible in the 1981 280zx manuel i looked up and when i ordered it from msa they much have switched it to a knock sensor in later years but not in the 81 motors which i have its the cylnder head temp switch and the alternator i am using is a hitachi and should be a internal regulator the old cylinder head temp sensor i pulled out had burnt on coolant and i am seeing white smoke from my exhaust so i believe he head gasket went out because i did over heat the car once not too long ago so right now i am thinking that the coolant is hitting the sensor messing up its input with the ecu but thats gust a guess Quote Link to comment Share on other sites More sharing options...
jpuga Posted June 16, 2011 Share Posted June 16, 2011 Dude did u figure out ur problem? I think I have the same issue. My fuel pump will die then the car will die then it won't even crank over I have to let it COO off a little. I have a 260 l28 carburated and I think its that little tube thing behind the alternator. Alternator is also internally regulated. Quote Link to comment Share on other sites More sharing options...
jpuga Posted June 19, 2011 Share Posted June 19, 2011 Found it it was my alternator. I took it to get it checked out and it failed their test 3 times got a new one and I was on the road. Quote Link to comment Share on other sites More sharing options...
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