I was having problems with my '80 zx dieing & not wanting to start after the engine got warmed up.. Someone suggested it might be the ignition module.. I had it check & it was bad, so I spent $150 on a new one... Now after installing it I have a new problem.. The car revs fine from idle to about 2500 rpm.. But if I try to go above that it's like it's hitting a rev limiter.. The engine stalls for a couple seconds then revs for a couple seconds then stalls again the revs again.. So far I've replaced the plugs, coil, ignition module, fuel filter, & injectors.. Anyone have any idea what could be causing the new problem??

 

Does it bog down like it's starving for air, run a little rough, then come back to normal?

 

There's no bogging & it doesn't run rough.. It's just like it's hitting a rev limiter.. It revs great from idle to about 2500 but anything above that it cuts out.. It doesn't spit or pop or anything like that, it's just like it loses spark for a couple second then it comes back for a couple seconds then loses it again (over & over).. It doesn't even seem to be letting fuel in while it cut off, it doesn't smoke or show any other signs of gas being dumped in while there isn't any spark..

The only part of the ignition system I haven't replaced is the pick up coil.. Is there any way it could be causing the problem?

 

get a diff o2 sensor and swap it in and try it..
im thinking its not reading your mixture properly right when you spool up

or like lww said afm meter also can be bad, in turbo AFM's it is designed to recognise the boost rpm and compensate for the air/mixture changes....

 

Also maybe your throttle body is gummed up. That happened to me with my '81 It wouldn't go past 2000 rpms. Like it was hitting a wall. I took apart the whole air system, and it turned out my throttle body was gummed up with antifreeze! Because one of my hoses burst, and it sucked the antifreeze through the air flow meter into the throttle body. I know it might not be same problem as mine. But it sounds like your car runs the same as mine did. Until I sprayed carb cleaner into the throttle body and it just screamed and blew the smoke right out! I was so happy, and it only took me 12hrs to find the problem! Anyway hope this helps

 

Possibly a bad throttle positioning switch? Allowing the car to start and run in the low rpm range? Or maybe the car backfired, and stuck the AFM plate in the closed position?

Ignition module? Do you mean the ECU box, or did you replace the magnetic pick up coil within the distributor?

Need more information!

Speed

Enjoy the Ride!

 

The car is a 1980 280zx (non turbo).. When I say ignition module, I'm talking about the little black box that is bolted to the side of the distributer.. I think the book calls it the IC Ignition unit.

Is there any way to test the throttle position sensor?

 

on the throtle position switch you can loosen the mounting bolts and turn the box wile the car is runing rev it at differnt positions if no change check it with a meeter in on and off position. I don't think this peac is your problem thogh because it controls your fuel pump. you sayed it wasn't fluding or poping or runing ruff, but still give it a try man. always remember KIS keep It Simple. don't think to hard and check the most ovious things.

 

Thanks for the help!!! It was something really simple.. I was testing the throttle position sensor & noticed that the connections were really nasty looking.. I cleaned the plug & the terminals on the sensor & now it runs great.. How can something so simple cause so much aggravation??

 

I had an 82 that did that after I washed the motor. It kicked my butt and then after a week of messing with it I unpluged the wires going to the module and repluged them and it ran fine So I am assuming that was your problem as well.

 

Dude! I'm the man. The throttle positioning switch was my first thought!

Speed

Enjoy the Ride!

 

Good call Speed! Glad to see there is still humility in the world!!! LOL...