3116 truck engine trouble

What kind of truck is it in?(Top Kick) Do you have an intake heater light on when starting? Does it do it all the time or just when it is cold?

Yup it's a top kick. No it does not have a intake heater. Just a standard engine. Does the injection pump have a screen on the intake side on the pump itself? I seen one that has had it on it before. Just a little unsure. And yes it does do this all the time if the truck sits overnight. During the day after initial start up, it will start up no problem. Just when it sits overnight, the next day it takes some cranking to start it

I had a 7.3L Ford Navistar that did this. If you have the HEUI injection system then they are basically the same. The high pressure oil pump can leak down and then must pump back up to hydraulic pressure to actuate the injectors before it will start. On the Navistar it took a rebuilt HP oil pump.

First thing to do is see if its loosing prime and this is easy look at the exhaust when you wind it over if it has little or no smoke you know you are loosing prime

If you are loosing prime its in the return to the tank side of the fuel system also check the pipe the runs down to the bottom of tank on the return is still attached

If you are loosing prime when you are driving its on the supply side if its when its not running its on the return side

It really is this simple if you cant find any leaks put a pair of vise grips on the last hose that returns to the tank and run it as on any motors I have worked on this builds pressure and you can soon find plenty of wet spots


Paul

3116 was 'mechanical' fuel injection, there is a screen in the inlet line just above the pump drive behind the timing case try using the priming pump before trying to start to see if it makes a difference. Fuel pressure is limited by the strength of the lift pump spring, also fuel run back can be caused by worn check valves in the lift pump. Make sure you only use the correct 'Cat' high efficiency fuel filters as any dirt getting through will soon wreck the injector pumps.

This is gonna sound dumb but I was crawling all over the engine to find the priming pump and can't for the life of me find it. Couldn't be easy like the 3208 lol I just hope it's something easy. I'm going to go get a Napa fuel filter today for it and check that screen out on the pump. Hope it's just something stupid like that.

Read Catsilvers last sentence, I got chewed by a Cat mechanic for using aftermarket fuel filters years ago. Who knows what micron they are? His words were " Cat designs their fuel filters to protect their systems" I never used aftermarket again

I believe what you say about cat filters. I just can't afford them nor the 60 plus Mile drive to the dealership to get them. Napa has always worked for me and the equipment I own. 2nd best isn't always bad plus I trust them more since my friend use to drive triaxle for a living. He used Napa filters all the time. His cat engine in that truck lasted 800,000 miles before it needed repaired. But anyhow, I'm still at a loss trying to find the manual fuel pump on this engine if it has one at all.

Cat is famous for being very expensive on equipment and replacement parts. Their filters are not expensive. Most of the time in my experience, they are cheaper than aftermarket.