I have a 83 280zx turbo 5-speed, i cleaned the fuel tank, lines, rail, new filter, cleaned injectors and harnesses, new spark plugs, tested wires, new cap and rotor( the one I had on there the center contact and plastic around was melted) battery tested fine, brand new week old alternator, ok now the problem, I can rev as high as I want when in neutral, when accelerating in gear though my car chokes and backfires very badly, especially once boost is applied, if the car sits for more then 10 or 12 hours it will run fantastic for about five minutes, then starts backfiring again, like I said though even after the problem comes back when in neutral I can rev just fine, each time I fixed one of the above components it would run great for a few days then the same problem persists. I'm running out of ideas and I don't wanna get rid of the Z shes all I have left of being a bachelor, I wanna hold onto this toy even though my new son can't ride with me yet! I know some problems are caused by corrosion on the ECU contacts, where is this at so I can clean them? Thank you in advance for any other ideas I appreciate it guys!

 

download the fsm from xenon so you have something to read when working on the car. ECU is by your left foot. probably the tps isn't working correctly. Chts is also a possible culprit. Use Deoxit by CAIG to clean contacts on ECU and AFM test the tps per fsm. might as well check your fuel pressure and ignition timing while you are at it.

 

I doubt its the TPS. it only has a cruse and full throttle switch inside it. I would check and clean the CHT first. make sure its withing spec and not corroded. then start checking though every sensor in the EFI harness.

 

I May have to beg to differ

I power washed my engine compartment before a show and the car ran exactly in the same fashion.

Dis-connect your tps if it is it the car will run the same. If its not the tps it will run worse.

What I did when I had a wet motor with the chugging and back fireing went along sensor by sensor till I noticed my tps was wet lil wd-40 car ran fine.

May I say everytime my z acts up I sit at idle and start plugging and unplugging till I had no differance in engine noise bingo theres the problem

 

Today I unplugged the TPS CHTS and ECU plugs and cleaned corroded connections on all three, with a knife and electronic cleaner, the backfiring and bogging down is completely gone, It still feels like it isn't 100% to me though, O2 sensor is next and when I get more time I'm installing this new clutch