I have a 1989 E-150 with a efi 302 and AOD. The motor has 147,000+ miles. Oil pressure is 25 PSI hot, vacuum is 17-20 inches, haven't checked compression. Fuel pressure is 33-35 PSI with key on engine off and with engine idling.

First cold startup of the morning the van is hard to start. It turns over fine but barely catches, and when it does catch it runs very rough for about ten seconds as the RPMS slowly pick up and eventually it smooths out and idles at 1000-1250 RPM until warm.

It idles nice and smooth at 600-750 RPM, but when hot, it pings wildly on any kind of acceleration, but more often it just bogs down when the throttle is first depressed and then surges. Sometimes it will actually stall, such as when maneuvering into a parking spot or taking off uphill from a stop.

New cap, rotor, plugs, IAC valve, thermostat, air filter, oil and oil filter. Pinging gets less if I fill it with 89 octane mid-grade gas instead of 87 octane regular (duh), but shouldn't I be able to use regular?

No trouble codes, I haev run the diagnostic tests with my OTC 2000 diagnostic tool using 1993 Pathfinder II software and found no problems.

I am at my wits end and contemplating a swap from the 302 to a 300. Does anyone have any suggestions as to what my be causing the poor performance, stumbling, stalling, and hard starting?

Thanks.