I have been reading most of the posts on here and ya'll all seem like you know your stuff, so please help me. I just bought a 93 f250 7.3 non turbo with 200k, 2.5 dual exhaust (2 mufflers because of noise police) and topped off with 5 inch echo tips(nice and loud). My first problem is starting it, even when it is warm outside (texas october) it takes about 5-10 seconds to start but if i plug the heater in it cranks right up, any suggestions? Second since it is loud i like to get into the pedal a little and when i do i see black smoke out of the one side mirror that i have, pretty sure it is on both sides (lol) could this be glow plug issues?? Third is that the ac/heat dont blow very hard, and the heat dont get hot and the ac just is cool. is this possibly a vacuum issue. The truck doesnt get vry warm so i am about to go replace the thermostat, any other suggestions for the heat not getting hot? Thanks guys

 

Slow starting is a glow plug issue,could be burned out or bad controler,many threads here on diagnosing it,black smoke is unburnt fuel could be dirty air filter,or pump could be turned up,theres a good tread of modifing you air intake to get more air,,heater not working could be plugged up heater core,it's easy to change.

 

thanks, the heater core was recently replaced i am hoping it has to do with the engine not warming up. i have also done some research and herad that the heat/ac not heating or cooling right might have to do with the door that closes and opens to blend the air, does anyone know where this door is??

 

to the left of the heater core I seen it changing mine.

 

there is a vacuum thingy on top of the black a.c. box under the hood. on the passenger side almost to the fire wall. look at it when you put the a.c. on max a.c. then change it to normal a.c. and look at it again. if it didn't move, then that is where it is messed up(for one thing) i just took that vacuum servo off and tied a string to it to where it is when the vacuum sucks it in. that is the door that decides between max a.c. and reg a.c. if that thing don't work, it is like its on normal all the time. the next thing, i ran a hot wire off a switch in the cab and spliced it in to the hot side of the a.c. blower motor. this made my fan run on super high when you flip it up and like normal when you flip it down. i have a.c. guages and i filled it with freeon, but the hot side was always too hot, so i had to change out the orfice tube and drier(black canister that gets cold) on the a.c. system. it works good now. as for the heat. my guage never goes ast the N and it gets plenty warm for me. umm be very carefull about changing the thermostat, theres some kind of water by-pass that can get covered up if you get the wrong thermostat or put it in wrong, the other guys can tell you about that better than i can. the glowplugs may need to be changed, it sounds like a couple are working but not all the way you describe it. the black smoke is fine if you have a clean air filter.

 

That door beside your heater core realy is a pain when all those parts get worn and it drags on the sides of the box,i fixed that part on mine,but my other door is hung up and i only get air out my vents on the dash,no defrost,but i'm not willing to stand on my head to work on it any more,replaced my blower motor,and four blower switchs,they always melt when on hi,i gave up on that too.its forever on low,but it throws so hot it does not matter,thats the only trouble with a truck that lasts forever,all the little things go away on ya,I call it character.

 

well my truck must be full of character(lol). Thanks for all the help so far i am gonna stand on my head tomm. and see what i can find. I think the thermo is bad cause it never even gets to the n in "normal"

 

Warning:if You Change The Thermostate Replace With Stock Motorcraft Anything Else Will Lead To Problems!!!!!