I have an 87 Buick Grand National and have a problem I can not figure out. Up to 65 MPH it runs great but anything above that it will start to hiccup or even completely stall for up to 3 seconds and then come back to life. I did find a bad coil pack and replaced that, I have also replaced the ignition module, crankshaft position sensor, the camshaft position sensor, the Mass Air Flow sensor, and the Throttle Position Sensor. Beginning to think computer may be bad or a bad chip? Anyone have any ideas or solutions??
Thanks in advance.