my 91 pickup will not start on a cold morning unless I leave a light shining on the computer that is located on the passenger side near the floorboard in front of the door.
Some have said this cold start problem may the cold start injector switch, but that is located on front of the engine. Are these two related????
Thanks

 

I think shining the light may just be coincidental.

I would be looking at

A. Cold start injector timer (the sensor)
B. Cold start injector
C. Wiring

Wiring is prone to breakage, and i actually ran into a similar problem on my race car (1985 MR2) where it was a PITA to start when cold, but started first click when warm. I found the wiring for the cold start sensor was cut.

 

First is the light a drop light that puts out decent heat? could be cold solder joint on the ecu board. The light keeps it warm enough to have good contact. cold and it contracts leaving a bad connection at the joint. Honda civics/accords have the same issue but with the efi main relay.

 

MY RUNNER did this for 2 winters ONLY WOULD START PARKED IN GARAGE...
turn out to die one day and it was ignition module/ignitor after i tried EVERYTHING!!!!!!!

 

I'm leaning along the lines of sloth! here, that the heat from the lamp may be compensating for a cold solder joint. However, it could be a corroded electrical connector anywhere that same area and the heat from the lamp is masking the issue.

IF you are finding it easier to start cold ONLY when you heat up the passenger side area, look for corroded connectors (may be caused by leakage from the heater core) in that area.