[badtoy]

every 500 to 1000 miles, after installing new plugs (already tested 8 diffrent set of plugs in any gap, in the last 4 months) my car begin missing at 5000rpm to redline. missing will be from mile to mile harder. missing at 16 psi and above. I already changed in the last 12 months the ignitor and all coils and serveral times the plugs and gapped them from 0.28 to 0.34 but nothing helped. when I install new plugs there are fine up to 500-1000 miles. when I checked all the used plugs they were fine, no doubt about that.
egt is fine at 640 C max, if the problem starts again egt raise to max 710 C. oiltemp max 115 C, oilpressure is fine, watertemp in normal range, fuelpressure 66 psi without a drop at 12v, injector cleaned and balanced by rc eng.
is it possible that one of the "new" coils is defect? or any other ideas?
thanks

mkiv bpu ++

 

[Xdreamer]

Check your spark plug wires. If your not running aftermarket wires go get some. the stock wires suck and caused the same problem on my supra. ~Xdreamer

 

[badtoy]

thanks xdreamer,
but the tt has a direct coil ignition, the na has 1 coil and a distributor with 6 spark plug wires. 2 diffrent systems.