Can anyone tell me if and where I can get assistance fro my 94 topkick with a cat 3116 in it? It' s hard to start and I want to know if I can stick a elec fuel pump on to solve the starting woes of the 3116.

 

The topkick should have an electric pump in the fuel tank that provides pressure to the injection pump. If it does not, NAPA has a line of commercial diesel in-tank pumps that will drop right in through the inspection port and then hook to the bail for the suction line.

One other thing about the Cat, it was available with both the problematic oil powered injectors and the mechanical injectors. I do not know which you have, but if you have the mechanical injectors, pick up the manual from Cat publication # 9GK37329 106-7879. The downside is the Cat tool group needed runs about $985 with commercial discounts.

The most common hard starting problem is use of fuel filters that filter particles larger than 2 micron, and/or dirty fuel filters. You want to use Cat filter #1R-0750 with the truck engine.

 

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Cat 3116 has mechanical injectors. The 3126 and later engines have electronically actuated, hydraulic fuel injectors.
BIG MIKE

 

I've had a lot of problems out of the injector tubes leaking in the 3116 and early 3126 with copper injector tubes that mainly can be seen after the truck is running though only in a few extreem cases have I seen it effect the starting.

Bryan

 

Thanks guys, I appreciate your help. I did put a check valve on to see if it helped. It did not. I do not have a pump (ELEC) at all. I am going to try that next and put some fuel additive with some lube in it to see if the arm that holds the kill solenoid on is sticking not allowing the oil pressure (pump) to rise enough to start. We shall see in a few days. If thats not it, time to swap the injector pump. CB

 

SOunds like your injector sleeves are leaking probably weak injectors. I would not run any other filter on there but a cat high efficienty filter.

I do about one 3116 a week sleeves and injectors.

Adam

 

Not true, the 3116E has the HEUI system, a few early 3126's had the mechanical rack system.

Both motors are absolute junk IMHO. If you want an engine under 10L get a DT466E or a 8.3L ISC.

 

Iron Horse,
You are correct about the 3116 HEUI engine. That is one I tried to forget!
BIG MIKE

 

Well I am sorry I did not have the 15 thousand to buy a International like some of the people here would. I had a limited budget for a truck and I bought what I could afford at the time. Thanks to those who did answer with legitimate replies.

 

I would take bigyellowirons advice and have the sleeves and injectors checked out.

I am going out on a limb here and may be dead wrong since I have not messed with any 3116's but I have messed with alot of 3126's which have the same block as the 3116.
It would be a good idea to check the oil pressure out of the HEUI pump, the APC valve on the HEUI pump and possibly dead head the pump to rule it out, as well as checking the rail pressure sensor.

 

Hey your 94 top kick will have mechanical fuel injectors. Do not try to adjust them with out the tune up kit and some good knowledge not to mention it is next to impossible to set the back 2 injectors because of the doug house, Does it have a hard time starting when cold? when started does it blow white smoke,if so your intake air heater is probaly not working, also if it's hard to start after it's been sitting or if it stalls after it's been running for a while check the plastic fuel lines running from the tank to to the back of the motor,they some times rub threw on the steel brackets holding them under the cab? Oh there's lots of problems it could be those thing's are a horror show I worked at a GM truck shop for many years, I was never out of work.There is no fuel pump in the fuel tank on that model of truck. Fuel pump is on the govoner, they can give trouble also ( Intermittenly!) Good luck if you need some more help let me now!