Chevrolet Repair: 1995 Chevy Blazer, fuel pressure gauge, chevy blazer

Question
HELP GUYS! Hey everyone, I am a 30 year old single mom raising a 5 year old little girl. Don't receive financial assistance from anyone and my explorer blew up (literally) So a "friend of a friend" sold me a 1995 chevy blazer (as is of course) for $1500. It has left my little girl and I stranded over 7 times in the past month. Haven't really had the money to fix it but it's having hard time starting. Once it starts its great for around town travel. Mechanic says that it is a "computer problem" and needs a wiring harness. Does this make sense. He claims there are no fuel pump problems. Should this be expensive to fix? He said this wiring harness costs $150 but I looked it up at auto zone online and it only costs about $30. I feel because I am single and have no help he is obviously trying to screw me over (with no vaseline) haha. Is there a way I could buy this harness and have a friend fix this for me who knows about cars, or do you even think that is the problem. Thanks so much for anyone's help--Bella

Answer
Hi Jami,  there could be several problems that could cause a hard start, try a fuel pressure gauge on it and run the truck, watch for pressure drop off, if none shut it off and see if pressure stays. it should hold for at least 15 minutes. check for a plugged fuel filter or blocked line. if you have an ign related problem, when cold check for spark. i don't know which harness you are talking about, so i can't comment much on that. but if you have fuel and spark then i cannot see the need for it.i would check all the connections for corrosion and clean them, unless you have burnt the harness i really can't see why you would need it.... hope this helps