Stage One Injectors
With the truck being a 2002 and having powder metal connecting rods in the motor, we wanted to shoot for about 400hp with this build. Any more than that and we'd risk breaking a rod and sending it shooting through the side of the engine block. So to keep our motor safe, Stage One single shot injectors were really our only option, which we estimated would give us a solid 50 to 75hp increase.
We went with Full Force Diesel for the injectors because of their dependable reputation, plus they're very competitively priced. These injectors from Full Force Diesel make up roughly 75 percent of their business, which keeps the company busy with the demand.
When removing the injectors, be sure to check and make sure all the O-rings are accounted for and haven't fallen in.
The 7.3L fuel injector is a unique piece of equipment. While the technology is now referred to as old and outdated, it was a very solid and reliable design. Before installing the rebuilt injectors you need to lube the new O-rings with motor oil to make sure they'll slip down into place without any problems. This will also help create a better seal, once installed into the cylinder heads.
If you're having a problem threading the injector, make sure a plastic zip tie from the gasket under the valve cover didn't accidently fall in. The nice thing about engines this old is that enough people have worked on them so we now know what to look for instead of discovering these possible problems ourselves.
With over 160,000 miles on what we assume are the original glow plugs, we did a quick replacement and included a round of Diesel RX glow plugs while we were doing the injectors.
There is one tip on the oil-driven injector install that will save you some time. The oil is on the outside of the injector so when you pull it, oil will seep through the hole and go into the cylinder. You could take the oil plug out and drain the oil, but that's time-consuming. The fastest way is to just take out the glow plug and turn the engine over a few times to clear it out.
"Pull the glow plug, put the valve cover back on and crank the engine a couple of times," says Tech Campbell. "The pressure from the piston inside the cylinder will push all the oil and fuel out through the glow plug hole and it won't drip back."
When you have a lot fluid in the cylinder and you put the glow plug in, that fluid inside may not have enough compression to push it out and can hydrolock the motor. If there is no room for the fluid to go it can bend a rod or break a piston, so you don't want to skip this step.