Tuning a 3306 in a PB 359

Hey y'all, Just picked up a 1986 PB 359 dump for the farm. The engine is a 3306 DI and was rebuilt and "turned up" by the previous owner. The fuel system is all mechanical but new to me and I'm looking for some advice on how tune it. I'd like to make sure the pump is timed correctly, set the low and high idle, turn the fuel down a little bit and in general learn the ins and outs of this particular engine. Let me know what y'all think, if you have any experience/knowledge of these engines/fuel systems I'd love to hear it.

Welcome to the HEF. Cool rig. If it runs good, I would not mess with it. Very steep learning curve to become proficient with that pump. And, a considerable amount of tooling is necessary. When I went to school for that pump, it was a 40 hour class at the Cat dealership I worked at. Then, it took a dozen pumps to get even half-way comfortable with them. Or, maybe I’m a slow learner? It’s easy to screw something up in the governor and have a runaway. That is, until you do three or four dozen rebuilds and then you can wing a few steps and do them in your sleep. First, locate a CAT 3306 Diesel Engine System Operation Testing Service Manual on EBay or you might find a free copy with an Internet search. Study that, first. The actual pump specs cannot be found in a service manual. You will have to find someone that can look that up for you in the Cat system under TMI. Some of the governor parts can only be found in the TMI and not the parts book.

Coaldust said: Cat system under TMI Click to expand... Which could be {Total Machine Interface} or {Too Much Information} or both.

Coaldust said: Some of the governor parts can only be found in the TMI Click to expand... Technical Marketing Information acksherley, often referred to as Too Much Information.

Coaldust said: Welcome to the HEF. Cool rig. If it runs good, I would not mess with it. Very steep learning curve to become proficient with that pump. And, a considerable amount of tooling is necessary. When I went to school for that pump, it was a 40 hour class at the Cat dealership I worked at. Then, it took a dozen pumps to get even half-way comfortable with them. Or, maybe I’m a slow learner? It’s easy to screw something up in the governor and have a runaway. That is, until you do three or four dozen rebuilds and then you can wing a few steps and do them in your sleep. First, locate a CAT 3306 Diesel Engine System Operation Testing Service Manual on EBay or you might find a free copy with an Internet search. Study that, first. The actual pump specs cannot be found in a service manual. You will have to find someone that can look that up for you in the Cat system under TMI. Some of the governor parts can only be found in the TMI and not the parts book. Click to expand... Roger that, appreciate the info. It doesn't run great currently. The idle is a bit low and it has a bit of a stumble occasionally when you try to get on it. There is a screw on the back of the governor near where the throttle linkage enters the pump, it's got a slot for a flathead and a jam but on it. Any idea if this a fuel screw or an idle screw? Certainly don't want a runaway so I will take the necessary precautions before messing with anything (turbo intake boot removed and a piece of plywood on standby). I will try to locate the book as you suggested, seems like a good place to start.

Please keep in mind a 3306 in a tandem is no race horse 300 horse is about it

sweitzerworks said: Roger that, appreciate the info. It doesn't run great currently. The idle is a bit low and it has a bit of a stumble occasionally when you try to get on it. There is a screw on the back of the governor near where the throttle linkage enters the pump, it's got a slot for a flathead and a jam but on it. Any idea if this a fuel screw or an idle screw? Certainly don't want a runaway so I will take the necessary precautions before messing with anything (turbo intake boot removed and a piece of plywood on standby). I will try to locate the book as you suggested, seems like a good place to start. Click to expand... That screw is the throttle stop. It bottoms out the external linkage, rather than forcing the internal governor parts past the design limit. The low idle screw is under a cover. Might check to see if you are getting full linkage movement. Lots of simple stuff to check. Intake air restriction, crankcase base pressure, visual inspection of the turbo, with a load of gravel, check boost pressure. Have the nozzles cleaned and tested. Perhaps, do a valve adjustment. The stumble might be the AFC not adjusted properly, especially if the previous owner was jacking with the pump adjustments.

That they admitted to "turning it up" will equal a great probability that they "screwed it up".

The problem---too many turn just the smoke screw without turning torque rise screw also. Back to--TMI--which leads to tampering.

Truck Shop said: The problem---too many turn just the smoke screw without turning torque rise screw also. Back to--TMI--which leads to tampering. Click to expand... it's so nice to bring it to somebody who can set you straight, do what is possible and no more, and send you on your way.

Nice short wheelbase , be a great city truck for tight job sites. Hopefully you can find a manual, or someone local to help you walk through it. I don't think of 1986 as being ancient, but then I started counting years....

crane operator said: Nice short wheelbase , be a great city truck for tight job sites. Hopefully you can find a manual, or someone local to help you walk through it. I don't think of 1986 as being ancient, but then I started counting years.... Click to expand... That truck is 11 years older then me. Im 29 have a kid a wife and am building us a house. Its old!

Tyler d4c said: That truck is 11 years older then me. Im 29 have a kid a wife and am building us a house. Its old! Click to expand... Oh no, your on the verge of farting dust.

Truck Shop said: Oh no, your on the verge of farting dust. Click to expand... 29 going on 93

111

skyking1 said: it's so nice to bring it to somebody who can set you straight, do what is possible and no more, and send you on your way. Click to expand... After a thorough vacuuming of wallet checking for any stray frog hides.

Coaldust said: That screw is the throttle stop. It bottoms out the external linkage, rather than forcing the internal governor parts past the design limit. The low idle screw is under a cover. Might check to see if you are getting full linkage movement. Lots of simple stuff to check. Intake air restriction, crankcase base pressure, visual inspection of the turbo, with a load of gravel, check boost pressure. Have the nozzles cleaned and tested. Perhaps, do a valve adjustment. The stumble might be the AFC not adjusted properly, especially if the previous owner was jacking with the pump adjustments. Click to expand... You lookin for part time work? But seriously, thank you. It seems like the linkage is getting full movement but I'm not exactly sure what's going on under the cover and I'm a little scared to look. I've checked all the simple stuff, air intake and turbo are good. No boost gauge on this truck unfortunately but I'll add it to the list. I think you're spot on with regards to the AFC being not adjusted properly. It seems like someone in fact cranked the "fuel screw" without doing the rest of the work. If you blip the throttle the engine sounds like it almost chokes, then coughs out a bunch of smoke and the idle then slowly falls, like a carbureted dirt bike with a vacuum leak. I've got a couple short videos I could share if I knew how. Getting someone who's knows what they're doing to look it would be awesome but I probably couldn't afford it. Appreciate all the help from everyone so far, seems like a great community y'all got here.

Something else that can cause that performance issue is the guvna flyweights on that particular pump can wear into the thrust plate and make the rack stick. Weak guvna springs can do that, too. Or, a combination of both. I can fix it for you, but the travel time from Alaska might be a deal breaker .

sweitzerworks said: You lookin for part time work? But seriously, thank you. It seems like the linkage is getting full movement but I'm not exactly sure what's going on under the cover and I'm a little scared to look. I've checked all the simple stuff, air intake and turbo are good. No boost gauge on this truck unfortunately but I'll add it to the list. I think you're spot on with regards to the AFC being not adjusted properly. It seems like someone in fact cranked the "fuel screw" without doing the rest of the work. If you blip the throttle the engine sounds like it almost chokes, then coughs out a bunch of smoke and the idle then slowly falls, like a carbureted dirt bike with a vacuum leak. I've got a couple short videos I could share if I knew how. Getting someone who's knows what they're doing to look it would be awesome but I probably couldn't afford it. Appreciate all the help from everyone so far, seems like a great community y'all got here. Click to expand... Looking at this the wrong way. IF you find the right guy, you can't afford not to take the help. You can park that truck in a jiffy, trying to find it yourself. You also have to value your time for something. you can beat your head against it for a few hours for days and days.

Coaldust said: Something else that can cause that performance issue is the guvna flyweights on that particular pump can wear into the thrust plate and make the rack stick. Weak guvna springs can do that, too. Or, a combination of both. I can fix it for you, but the travel time from Alaska might be a deal breaker . Click to expand... You probably need a vacation anyway