91 convertable, just started this problem. After about ten minutes running, engine light comes on and pedal response is like its out of gas. When I turn it off and back on, will run normal for a few minutes then same thing. Alternator seems to be charging. any ideas please

 

Sounds like a bad OMP and the car is going into limp mode. Have you tried running codes yet? If it is the OMP then the check engine light will come on when you open up the throttle and it will put the car into limp mode.

 

if it is the OMP than i've heard it take sthe computer out with them.. so you would need a comp and OMP...

 

engine light comes on without opening throttle. just start it, wait for it to warm up and light comes on. still omp?

will check codes tonite thanks

 

Im not positive, but it sounds like the OMP. And it doesn't always take the ECU out with it. I had a bad problem with my OMP and the previous owner did too for over a year and my ECU still works fine.

 

Sure its not heat light?? Could be a stuffed cat, as a major blockage in exhaust will kill all power.

 

thanks, checked code...27 so it's omp or ecu i think. I'm following service manual steps to determine which one. I'm stuck on step #2. what is a stepping motor? where is it?
where is the control unit? how is that tested? how do i test continunity between stepping motor and ecu???

thanks for any and all help!