I've got a problem with my 84 Mark VII, 302 CFI, that has had me scratching my head for quite some time. After 9 minutes from a cold start (Within 30 seconds either way,I've timed it!)each and every time I drive it on my commute to or from work, the engine will stumble, miss, hesitate and lose power for 2-3 minutes and then run perfectly from then on. I've never been able to duplicate the concern in the driveway or on a road test with equipment at hand for testing. There are no Continuous Memory codes set and none show up on the KOEO or KOER. I've wiggle tested the wiring under the hood numerous times. The fuel pressure at the TB is fine when tested, although I've never tested the pumps individually.
The problem first surfaced last December at about 108K miles. In February I pulled the engine to reseal it, mainly due to a leaking rear crankshaft seal and rusted oil pan. It got the full treatment along with all of the engine gaskets and pan: Plugs, wires, cap, rotor, pickup coil,TFI, oil pump, water pump,all filters, hoses, belts, O2 sensor, ACT sensor, ECT sensor, TPS, EVP sensor, cleaned the EGR spacer, and installed an EGR filter in place of the cooler. Most of this was done "because I was there" as most parts were original and long overdue for replacement. I didn't want any surprises a week later. You know, those "Damn, I should have..." moments I thought sure that after all of this the problem would be gone. Nope. The maiden voyage after reassembly was a 300 mile round trip. 2 cold starts and the problem occurred at 9 minutes into each then disappeared until the next time. It's showing
132K on the odometer now, and the problem still happens like it has since day one. Any thoughts would be welcome.