Momentary Engine Stall 2.3L
The engine will stop running, and when moving will restart in less than a second. At highway speeds the RPMs will drop by about 200. The Speedometer will drop like a rock, dropping about halfway down the gauge, showing a lower speed than the truck is going. The theft light comes on and then goes off in a couple of seconds as the truck restarts. It has also turned off several times when the truck was stopped. When it does, I have to restart it with the key.
The check engine light has not come on. When I check for codes, I have only seen two pending; one for A/C system, the other for the ABS.
What I have done: Replaced the ignition switch, tested relays, installed a remanufactured PCM, and had keys made for it. I thought it was a PCM problem because of the speedometer behavior and that the off time, of the engine, was so consistent. I have also checked the fuel pressure: I am driving around with a fuel pressure gauge wedged under the windshield wiper so I can see it. The engine hasn't stalled since I set up the gauge today. Fuel pressure steady between 65 and 67 PSI.
Observations: It doesn't seem to matter if the road is rough or smooth. It has happened when the truck is stationary. It has happened early in the morning within a couple of blocks of the house, temperatures in the 70's, and it also happened with temperatures in the triple digits. When the engine goes off - The Headlights, Radio, A/C continue to work.
I would appreciate any help on what to check or suggestions on what could be happening. I now know enough about the PATS system to know that I know almost nothing, half of which might be wrong.


