My sons tuned up their 85 FB autocross car (really just changed plugs, but that is all it needed) yesterday. They also added a K&N filter (OEM replacement). However, although the car idles more smoothly, it takes a crap at wide open throttle and has trouble revving to even 6000 rpm. DK what happened.

 

Make sure plug wires are on correctly. Also check fuel filter and ignition cap and rotor.

 

Plug wires look ok. I will check fuel filter, cap, rotor, etc. What is bothering my is that it was running well before the tune up.

 

if you have the carb'd 12A check out this thread... easily missed when going over your carb
https://www.rx7club.com/1st-generation-specific-1979-1985-18/common-cause-power-loss-nikki-carbureted-models-632007/

 

Removed and reinstalled air cleaner and that took care of the problem. Something must have been binding the linkage. All is well now and my son Sean took second of three cars in ES Saturday at an NEPA SCCA autocross and won on Sunday.

 

It's the little things...