2.9 running problem in 1988 B2

[sgrasso]

I just bought a 88 B2 with only 89,000 miles (confirmed with carfax). Drove it from San Francisco to Salt Lake City and it ran perfectly until the last few miles. I started up one of the canyons outside Salt Lake City and the engine quit. I had it towed to a Ford dealer. They replaced the in tank fuel pump and fuel filter. The car runs now but when driving up the canyon and around Salt Lake periodically the car goes through periods of loosing power then as if a switch is turned the car runs as it should. Then this cycle will start up again a short time after, loss of power then normal. The loss of power is more dramatic the higher up the canyon. If I hold the throttle to the floor it seems to run better. If I pull the car to the side of the road during the rough running time a few moments will pass and then like a switch is thrown the idle smooths out to normal. The same rough running happens going down hill. Salt Lake is about 4,600 the canyon I have been driving up goes to 9,600 in about 6 miles. Any suggestions will be greatly appreciated. Steve

[Loanranger]

I would suggest to check your base timing. Remember to pull the pill, or you won't get an acurate reading.

[sgrasso]

The timing was checked when the TFI was replaced. Thanks.

[87Ranger4me]

I would start looking at the MAP sensor (manifold absolute pressure) as it has to do with metering fuel properly at higher elevations. See:
http://en.wikipedia.org/wiki/MAP_sensor

[MAKG]

If it's going on and off like that, it's electrical. Probably a ground. I'd idle it and go wiggling every wire in sight. Don't forget the battery cables.

And run the self tests.

[88RangerXLT]

If the TFI was just replaced check the connector going to the module. Mine had the exact same problem, and auto-zone sells the connector for17.99

[Psychopete]

I'd idle it and go wiggling every wire in sight. Don't forget the battery cables.

You'd be surpised what you can find by doing this. I had someone help me, and thought it was just a waste of time. My truck was intermittently dying like the ignition system was loosing power. Found the problem in the positive going to the coil, the terminal on the coil was corroded as well as the plug. Cleaned up the plug, but bought a MSD Blaster II coil with a gift certificate I had, since I was too lazy to clean up the old coil terminals. Oh, and I also applied dielectric grease to the new coil terminals.

Pete

Edit: Oh, and whenever a passenger shut their door, that would kill it, too. :)