i cant seem to find out what is wrong. so i am making this post to see if anyone can help me. i bought the truck for $1600 and so far its been decent other than it starts real rough and doesnt like to go uphill at all it stutters and drops down to 10 mph and doesnt rev and i have looked every where, i am guessing theres a crack in the vacuum resivoir because i get vacuum going in but not coming out. also when i go uphill it tends to shoot the cylinder 5 plug wire off and the cel flashs but now it struggles to go anywhere on a slight incline and i cant figure it out ive gone through everything i can think of but its so cold in vt right now and i dont have a shop to work in so i cant stay out for to long but i just need to figure out if i can find how to get vacuum past the resivoir so my heat will work out of my vents instead of just my defrost.

i have also replaced the maf sensor and the air filter