About a week ago my tpi started to miss, only with a/c on. I thought plug wires, seen it before. I put some Taylors 8mm on it .
No, didnt help now the plugs are not very old , so i haven't replaced them. I also think that if a plug or two were bad it would miss under WTO which it doesn't. Now if i let it miss for about 5 minutes i get code 44 lean exhaust. Thats strange I can smell a rich exhaust < HC 500+ > sec. air not connected. so I checked wiring: grounds good, connections not loose. I dread looking at my tach it just bounces when it misses.Turn off the a/c it stops. One more wierd thing take the alt/fan fuse out it stop. check the alt its fine check the fans (running 2 : 14'' , 16'' ) 2 relays. The relays have a switched power wire in common with the alt turn on lead (brown wire ) . My next things are a ignition mod and plugs. Now the code 44 maybe a secondary effect do to the miss or not. Otherwise this thing is a rocket , (stock chip)



91 rs with a TPI

If you have a volt meter, check the system voltage with and without ac/headlight load (should be at least 13.5 volts). May be as simple as dirty or corroded battery post connections.

I have 2 batteries on the car ( high power stereo system) . Voltage on the car , which i checked at different locations is normal about 13.3 with a/c on . With all electrical loads on goes to 12.5 thats with the stereo on (800 watts ) 2 JL audio amps. but why would the missing stop with the alt off( batteries only)thats my problem.