I purchased a 82 280zx from a friend and I finally got it running..It was running very poor until i played with a sensor on the passenger side going into the block..not sure what it is..But it idled out smooth..No stumbling..So i got excited and took her down the road..I gave her gas and kicked it..It quickly accelerated to 3k and started to break up..once at 4k..ran great again..i shifted to second..and hit 3k..and stumbled and sputtered again..so i kept pumping the gas until she got past it to 4k..then it ran great again..Im at a total loss as to whats causing this issue..Ive replaced the fuel pump..cleaned the afm..and replaced the tps..Thanks for all your help!!!

 

Sounds like maybe a dead spot on the AFM? Did you do the AFM refurbish? You could also have a bad connection on the AFM connector.

The passenger side sensor was probably the CHTS that you were messing with...

 

Welcome to the forum. The AFM rebuild that FricFrac is referring to is located here:

https://www.zdriver.com/forums/240z-280zxt-s30-s130-tech-tips-275/js-how-rebuild-your-afm-15277/

You may also want to try getting some Deoxit or some other oxidation fighting electrical cleaner and cleaning all of the connectors around the engine especially the one that plugs in under the AFM. Good luck, keep us posted

Also: got any pics of the car??

 

thanx for this info i will be doing this on saturday

 

Ok..So tonight i removed the coolant head temp sensor..No coolant came out..is this normal???it had calcium build up on it so i cleaned it and put it back in..Didnt make a difference...I also did the afm refurbish as suggested and also made no difference what so ever..I did notice that when I unplug the TPS sensor..No change...No idle change no performance change?...I unplugged the chts which i guess mean coolant head temp sensor..and it idles very rough..but accelerates a little smoother..but still hesitates...also i looked under my passenger seat and noticed a bunch of wires going into a box and what looks to be some relays..What is this??...sorry for so many questions..Its my first z...Thanks for all of your help!!...Chris Jones

 

You seem to be on the right track... Let's start simple and go from there.

Have you done a tune up? You know... plugs, plug wires, filters, cap & rotor.

Have you pulled the spark plugs, and what do they look / smell like?

How old is the coil?

With these cars, sometimes the simple stuff is the fix.

 

cylinder head temp sensor, not coolant. stuff under pass seat is for cruise control.

 

yes i have changed the plugs wires dizzy cap..rotor button..coil..i just ordered a chts