I have a 1991 F-150 with 4.9 I6.

It is running rough, hesitation, cuts out, etc.

This is what I have done to it.
Replaced fuel filter
Replaced PCV Valve
Replaced Spark Plugs
Replaced Spark Plug Wires
Replaced Complete Distributor
Replaced Rotor, Cap
Adjusted Timing
Ran 2 tanks of Seafoam

The shop tells me that it needs the injectors replaced, which is going to cost about $900.

What I was wondering is how hard is it to change them myself, and if there are any instructions/manuals/pictures out there anywhere on how to change them. Also is there any adjustment or calibrations once the new ones are installed?

 

Stay away from that shop. Ford injectors virtually never go bad, even when they're fouled with rust or varnish. My engine sat in a junkyard for a few years to the point that the injectors wouldn't even open, and after forcing them, it has run perfectly for ~13 years now.

And you can buy sets of used/new injectors on eBay for <$100, and it takes less than 2 hrs to change them, so the job should cost <$300.

Get a Haynes manual (the older, the better) and follow the ignition diagnostic procedure.



Click my black Bronco in my sig, read the captions in the '90-96 Fuel System album, and test your fuel pressure with a gauge.