I have decided to keep running my current 5.8 liter engine until I have to replace the motor but want to put new injectors in as the fuel mileage has gotten bad after 135K miles. I have never dealt with a fuel injector system and cannot find a youtube video. How hard are they to change? Is there a simple procedure guide I can go to to help me do this? 1993 model. Thanks.

 

You have to depressurize the fuel system (pull the wire off the inertia switch in the cab, run until it quits) remove the upper intake manifold, and associated thermactor solenoids on the drivers side of the engine, just take pics so you reassemble it all correctly.
The fuel injectors and rail are now out in the open, 8 plugs connecting the injectors to the wire harness, 4 bolts holding the rail, pull the injectors straight out towards you, replace the old ones, and re-assemble.

 

Thanks for your answers. I suspect injectors because the idle is a little erratic and fuel mileage has decreased over time but I am not getting a check engine light. Basically, a place to start. I guess I need to get a shop manual as I have no idea where the O2 sensor is. I can check the compression and expect it to be low due to W&T and mileage. Is it best to replace all injectors at the same time if I find a bad one? Prices on Rock Auto sooo much better than local shop, I thought I would be better off to order them before tear down just for down time of vehicle.

 

Good advice Ken...

 

OK, thanks again!

 

I have to admit.............
After rebuilding my 460 and re-installing it, having it run PERFECTLY right off the bat, and no carb tinkering was kinda impressive.
EFI has scored a couple points with me................I still hate computers though.

 

I've read that, thanks for reminding me.

 

I'm the same way. Computers AND electrical. I restomodded a 1973 Corvette, doing all the work myself. Only 20 years difference but my '93 F-150 has a lot more of those items that I don't know much about. Oh well, time to learn some new tricks I guess!

 

By the way, how many O2 sensors in my '93?

 

Only 1 on my 460 F-250..............in front of the cat. converter.

 

to de-pressure the system, just put a fuel pressure gauge on the fitting on the rail, and hit the button
After 87 hitting the inertia switch shuts the fuel pump off, but does not release pressure. The truck won't start, but will still have pressure on the rail

I go with Ken on symptoms, but also add a blocked, or mostly blocked cat.
Once the fuel starts getting more than the cat can burn off, it tends to melt them down, later, they start to break up inside
This usually ends up putting pieces of the cat in the muffler, and making that an issue as well
Hold a dollar bill by the end near the tailpipe while the truck is running
If it blows away, no worries, if it keeps flapping back, and trying to suck into the pipe, then push back out, you may be thinking about a new cat and muffler in your future

 

Don't forget to lubricate the new O rings or you'll have trouble. I used Vaseline on mine.