CAT 3116? Fueling

[dzlfarmboy]

Anybody ever fool with one much, I have a friend with one in a box truck and is having issues with a hard start and I believe it has a grid heater on it and is working properly. No 100% what the fuel system is like on those. Any tips would be a help.

Thanks Brett

[BigYellowIron]

Is it hard starting hot as well?

[dzlfarmboy]

I think it's ok after it's warm just when sitting for a while even when sitting in a warm enviroment.

[BigYellowIron]

I would start by replacing the fuel return check valve. It is located on the front of the engine just above and the front of the govenor there is a valve and spring in there. Its what regulated the fuel pressure and keeps the fuel from running to the tank after it sets for a while.

[wdimig]

my dad has a 3116 in his snapon tool truck, that thing is a pig, but i know that there is something wrong with it, from the small knowledge that ive gathered on this engine, it sounds like it needs a overhead adjustment the valves and the injector syncronization needs to be checked. they also had issues with the injector bore seats in the head coming loose, which would alow compression to get into the fuel system, and it really kills the power, also they dont like the be idled, and generally seems to hurt them. i have some oil leaks to fix, the cam boxes are leaking, but they can only be taken off once the rockers, and push rods are taken off, just like the Cummins N14 engines, but the cats dont rely on gasket thickness to determine the fuel injector timing unlike the N14's, thats a fun repair to do! i did fix the leak on the driver's side of the engine, the oil return casting in the block for the HEUI fuel system has a plate cover with a large oring that seals the plate to the block, the oring was very stiff, brittle, and flat, it really leaked when the engine was cold, replaced it and no leaks there. sorry for the long post, I just thought i would share my teeny tiny bit of knowledge that i have on the 3116 engine.

wes

[mhuggler]

Originally Posted by wdimig

my dad has a 3116 in his snapon tool truck, that thing is a pig, but i know that there is something wrong with it, from the small knowledge that ive gathered on this engine, it sounds like it needs a overhead adjustment the valves and the injector syncronization needs to be checked. they also had issues with the injector bore seats in the head coming loose, which would alow compression to get into the fuel system, and it really kills the power, also they dont like the be idled, and generally seems to hurt them. i have some oil leaks to fix, the cam boxes are leaking, but they can only be taken off once the rockers, and push rods are taken off, just like the Cummins N14 engines, but the cats dont rely on gasket thickness to determine the fuel injector timing unlike the N14's, thats a fun repair to do! i did fix the leak on the driver's side of the engine, the oil return casting in the block for the HEUI fuel system has a plate cover with a large oring that seals the plate to the block, the oring was very stiff, brittle, and flat, it really leaked when the engine was cold, replaced it and no leaks there. sorry for the long post, I just thought i would share my teeny tiny bit of knowledge that i have on the 3116 engine.

wes

If it's a HEUI there's no rack to syncronize.

[wdimig]

it's a 96' 185hp, soo it probably is mechanical, my bad on that. that would make sense. he's probably going to run it unit it blows, and then we will probably put another engine in it........do i see a cummins sitting in it??????

wes

[IKNOWEVERYTHING]

I used to work on 3116's they are less than idea engines the early verisons had problems with injector cups cracking/leaking fuel into the cooling system,run hot because no one looks at the water pump belt (why put a belt to small to fit over the harmonic balancer,that only runs the water pump and is a bastard to adjust? Good thinkin Cat) general low power,eat altornators and batterys do to the intake grid heater staying on for something like 3 mins straight. All this in a Chubby/gmc chassis.....yaa !

Happy to not work on them any more !! ! !

IKE

[wdimig]

Originally Posted by IKNOWEVERYTHING

I used to work on 3116's they are less than idea engines the early verisons had problems with injector cups cracking/leaking fuel into the cooling system,run hot because no one looks at the water pump belt (why put a belt to small to fit over the harmonic balancer,that only runs the water pump and is a bastard to adjust? Good thinkin Cat) general low power,eat altornators and batterys do to the intake grid heater staying on for something like 3 mins straight. All this in a Chubby/gmc chassis.....yaa !

Happy to not work on them any more !! ! !

IKE

yea i dont even want to spend the money, to get the tools to do the injector syncronization, you hit the nail on the head about them eating alternators, the grid heaters do stay on for an obnoxious amout of time, i sometimes think that they are just stuck on, and then the light will go out. like i said, it runs, but that's about it, very low on power, it had a little over 150k miles on it, and the majority of that is city driving, and i know he idles the heck out of it. like maybe 4-6 hours a day.

wes

[wdimig]

soo we were doing the brakes and some other things yesterday, and we decided to pull the aftercooler to clean the radiator, got eveything unbolted, amnd was working on getting it removed, when i noticed tha the tank on the cool side of the cooler was moving, not only was it moving, it was split!, by the time i got it out of the truck, the whole end of the cooler had just about ripped off!!!!!!!!!!! soooo i kinda figured out why the truck dint have any power, or wasnt building boost, the cac pipes didnt really look dirty, soo i cleaned the boots up, and hopefully will be getting a new, or rebuilt aftercooler today. hopefully this is all what the problem was......