4.3 V6 Issues...

My truck is at a point where it will either not start at all, start and immediately stall out, or start and run EXTREMELY rough to where I can't seem to get it above 25 mph...Anybody else ever experience this, and if so what turned out to be the cause??...Also, if I end up having to take it to a shop, should I bring it to one that can run a computer-diagnostic on it, or would that not matter in this situation??...Appreciate the feedback peeps!!

dude sounds like you need a fuel filter...could be choking up.

check the fuel pump for pressure, fuel filter, and the mass airflow sensor. mine ran like shit till we figured out i wasnt getting the right pressure from the pump. could be a combonation of things too. good luck with it

when you get it running EXTREMELY rough is the exhaust glowing red ?? if so the cat is plugged.

Thanks for the replies...turned out to be the coolant temp. sensor which was telling the truck it was 40 below outside, and had to change the plugs because they were all messed up from the gratuitous cranking.......

Dude i had and have the same problem. I got the 4.3 with a lil over 104,000 miles on it. I got a tuneup, changed my fuel and air filter, etc etc. and it still ran like shit. You need to replace the distributor and cap. My problem went away, now i have slight tranny probz