I just picked up an 86 f350 4x4 crew cab with a 6.9l and 4 speed trans. drove it two hours home without a problem besides the fact i was pretty much floored the whole way home and barely kept up at 55-60 mph.

im not sure how many miles are on it its says 96k which it maybe as it was used as a ranch truck and the motor looks untouched. ive searched and it looks like a new injection pump and injectors will make a difference. What else are some known problems i should be looking for?

oh and heres a pic of when i brought it home and after with a coat of primer.

 

If you leave it non turbo, get the pump rebuilt and have them turn it up 10%. Really makes a difference, and if you cant get it done there I can get it done up here. Some cali shops wont do anything but stock.


Oh and it looks brand new with primer.

 

i plan on leaving it with no turbo..well i actually lucked out and i have a friend also with an 6.9 in his f350 welding truck and he has a new rebuilt spare pump which im going try. Is there a way to test the injectors?

 

Before I started changing parts, I would look at the fuel filter, air filter and exhaust, If the exhaust is stock, it is probably half plugged. I'm not saying you may not need a new ip and injectors, but it will usually run better than you described the day before the IP dies.

 

wish u where closer i so i can give u hand but if the ip was swap out make me lean to timing has the truck been timed

 

So you've got a 86 crewcab 4x4 diesel that looks amazing. I am jealous. I wanted one but ended up settling for an extended cab. I guess I am happy with the extended cab though because even it is almost to long to drive in small parking lots.

I have a 85 NA 6.9 4x4 that will absolutely bury the speedo needle and thats with a C6 and 3.55s. In fact, I do it all the time, sometimes everyday. So, don't give up on it!

 

well i changed the fuel filter today it seems to start better when its cold. the air filter is clean and it still has the tiny factory exhaust. i drove it around it still feels the same. Its kinda hard to explain but when i rev it up it seems like its surging, missing. Anyone know what could be causing this?

 

yes.


sounds like it could be injectors too of course.
the ip and injectors are medium ware items and typically go for 100k miles at peak performance.
a complete idi tune up is a good place to start,after making sure her compression is still healthy if you plan to have the truck for a while,which looks like you do,based on the body work done.
making sure you don't have a weak/failing lift pump is a good place to investigate when she seems to be lacking power/struggling to run good too.

 

Surging is also a sign of an air leak between the tank and the mechanical pump.

Cut that muffler off, I bet it weighs fifty pounds, if it is the stock muffler, I would bet it is pretty stopped up, and they weren't any good new.

 

THIS.

Not sure about the surging, but would assume fuel.