Hi guys

I am fighting with my 89 L98 Trans Am. Few days ago I have changed valve seals. As you know after that I have to set the valve lash. I did it (with 1/4 turn after zero lash) Car runs but have slow throttle response and low power overall. So yesterday I decided to go another 1/4 turn. Engine runs better and has more power. But...after 30miles when engine gets full warm temperature problem appeared. When I stood on red light Engine shaking strong (500-3000rpm) sometimes dies and sometimes get high idle (2000rpm for example)

I've parked the car and returned when cold. Start the engine and drive 15miles without any problems. Could this caused by too tight valves?

regards

Do you have stock injs ?

yes, stock. replaced 7mths ago.

Sounds like you have valves that are too tight.

Adjust them with the engine running.

No substitutes.