I have a 1991 F150 4x4 302 5 speed. I just recently pulled the motor and tranny out and swapped in another 302 I built and swapped out the 5 speed for a C6 automatic. I left the xfer case as is, BW1356, but due to the heads being 1965 289 HiPo heads there is no smog pump inlet so I removed the pump nd the connecting hoses. I started her up last night after many hours of installing the new motor and tranny and I have a very rough idle and it won't idle in gear. This is all due to a vacuum leak somewhere but not sure where it is. Hope to find it this weekend.

Well to make a long story short I have a few questions:

1) what to do about the 2 vacuum lines going to the smog stuff? I just pluged them.

2) There was a sensor inthe back of the block that I pulled, but the motor I built doesn't have this sensor, what is that sensor and what does it do? Do I need it?

3)Any computer problems you can think that I need to address?

Thanks in advance

 

What color are the wires going to the mystery sensor? Pull any codes from the computer, and it will let you know if it is happy or not.

 

Well it turns out that that sensor is the knock sensor. Do you need to have this plugged in? What will it do to the timing without it?

I fixed one vacuum problem I had but it still runs real rough. I am going to install new wires and a cap and rotor. Also got some carb and choke clean to find out if there are any other leaks.

The major problem I am having is over heating. I replaced the stat and tonight I am going to pull the water pump.That is the only thing left. I just used the waterpump for mthe motor I pulled. Maybe it sh#t the bed??

Any help with the sensor problem would help.

Thanks