1991 Ford Truck

Engine Performance problem
1991 Ford Truck Two Wheel Drive Automatic 125000 miles

Hi there,
I have a few issues that I'd like to bring up hopefully you may have an answer for.

Let's start at the beginning.
Sometimes upon startup the engine will cutoff, happens randomly, I have tried it with everything on, nothing on, radio on, heat/ac on, completely random.
the RPM when I first got this trucked stayed anywhere between 1 and 2 upon startup, it now drops to about.5.
Next when driving at lower speeds the engine sputters and knocks - sometimes to the point it will cutoff - I have been using STP fuel injector cleaner every other fill and it is still not running well, this is worse if I try to stay around 30 - 35MPH. At Higher speeds driving I have no issues at all. Also if I'm below a 1/2 tank of gas and it rains, my alternator will turn over but does not start.
I really don't have alot of money to have this professionally checked and I was hoping someone/anyone might have any idea/answer - no matter how minimal it is just to get me started on the right path.

Thank You.
October 20, 2010.

This truck has a lot of issues, you have told me all the problems that you have but have not told me any maintenance you have performed on the vehicle.

Dr Loot
Oct 24, 2010.
Maintenance: Oil Change Regularly
Check Transmission/Oil Levels every other fill up

Spark Plugs and Wires (I just thought about this): These were replaced last year and this is when part of the problem started up - low idling. (I did check today - looks like one of the spark plugs is cracked - I will have this replaced tomorrow more than likely)
Fuel Filter was replaced at this time as well.

Battery and Steering column replaced: Battery died over time, steering column had to have the ignition switch replaced due to snapping (extremely cold weather)

Fuses get checked once per month (no problems ever)

These are the things I can think of off hand.

Last year had the Water pump replaced - cracked.

Oct 24, 2010.
Okay thanks for that information, the first thing you need to do is replace the spark plugs that is cracked, and make sure you check them all that me know what you find.

Dr Loot
Oct 24, 2010.