I have a 94 F-350 7.3L Turbo Diesel with about 127K miles on it. I recently had the fuel and air filter changed by the dealer. Whenever I accelerate with a heavy load or going uphill, black smoke starts bellowing out of the exhaust pipe. I was wondering if anyone can tell me what my problem might be????

 

First, let me say, I don't own a diesel, but my brother in law does. It sounds to me like there's nothing wrong. Most any diesel will blow smoke like that when under a load, like going up hill. See what other responses you get, but I wouldn't be too concerned if it doesn't smoke all the time.

 

Hmm........don't think I'd go along with that verdict at all.


To start out while driving unloaded that truck shouldn't really smoke at all, especially bellowing out smoke as you put it. Black smoke is usually an excess of fuel in the combustion chamber. Since this is a 94 it can be either an IDI or a PSD. Which engine is it? The IDI uses a mechancial injection pump and the PSD uses high pressure oil so they're 2 completely different beasts. Do you have any performance mods on the truck and what kind of load are you talking about pulling? Typcially when going at speed the turbo has spooled up so there shouldn't be black smoke. I could possibly see some black smoke under HEAVY load or acceleration from a stop since the turbo hasn't spooled up yet and without the extra air the fuel mix is too rich. Even in those circumstances on a stock truck there should be little to no smoke. I can't really venture a guess as to what could be the problem until we know if its an IDI or a PSD. If this started right after the dealer replaced the filters I'd start off checking the air filter for anything amiss, as it sounds to me like you've got some sort of air restriction. You might also consider pulling off the air intake tube and inspecting the turbo fins for any signs of dusting (basically sandblasting) which occurs when dust gets past the filter.

 

It's the IDI and it has no mods to it. It was a very heavy load that i was pulling (John Deere 4020 tractor with gooseneck trailer).

 

I'd say in that case, it better be smok'n!! If not, then you do have a problem.

 

Did you ever find out if you had a problem with your truck??

 

Why should it be smokin?
And yes, I think there is a problem with the truck. Either that or the engine is shot. Hauling a 310C John Deere Backhoe on a gooseneck trailer through the twisting and turning hills of southwest Missouri wasn't a very easy haul. I could barely make it up the hills at times, slowing down to speeds as low as 20 mph. I was glad to make it back home. I'm not even gonna worry about the truck anymore though; I think it's time to get a PSD with DRW, because the IDI isn't cuttin it.

 

You may try some power service conditioner with a few tanks. Its usually a good thing to run on a regular basis to keep the injectors and pump lubricated better, as well as keeping the diesel conditioned. As far as smoking the way you were talking it sounds like its making ALOT of very black dense smoke, if so, then no its NOT supposed to do that. It would smoke some under a heavy load, but not profusely. I looked at buying a 94 IDI like yours and unloaded it would never smoke. While pulling a load it didn't make any smoke either. Its possible your injection pump is going south on you. I would take it to a diesel shop (NOT the Ford dealer, unless they deal in alot of diesels and large trucks) and have them inspect the pump. I would also have them do a compression test on each cylinder. Its possible that the rings are getting worn out and you're not getting enough compression to fully ignite the fuel causing the overfuelling conditions that you're experiencing.

 

Alright, thanks for the help.