No CEL and no code when I check with the key.

 

I would just fire the Jeep up even for 15 seconds so the rail is completely up to pressure and then shut it down and remove the rail leaving everything attached (Injectors fuel line etc) There will be enough pressure in the system you will see one of the injectors dripping if you have one stuck open a bit.

 

It takes 45 seconds to have 0 pressure so that wouldn't work to well.

 

Just turning the key should run the pump. Of course you would want to be sure the keepers are snug. I find mine (rail), to be a real wrestling match, takes a bit of pressure sliding all those O rings. I lubed them, work up and down, side to side a little, takes all I got with that leverage. But they go.

 

Then do it for as long as it takes. Don't make me have to come in there!

 

If anything plug 1 is cleaner than the others. The plugs seem to have an unusual amount of build up on them for having ~5000 miles on them. They are auto lite so I will change them to champion copper tomorrow as all the parts stores are already closed.

 

I have a 94 also. It does not have a down stream o2 sensor.

 

I guess if your sure you want to do the swap you might as well do it all at once. I suppose the check valve in the pump IS the normal culprit, but have to be curious if you would find injectors leaking.

What kind of deposits? Brown/tan old looking or black carbon?

That front lite one might be a vacuum leak? (if you find a couple easy to reach manifold bolts are loose, you gotta pull the air cleaner and do them all, starting at the middle and working out a few times)

(and thanks bigz)

 

It is tan build up on the electrodes.

 

As I was changing the plugs I noticed the vacuum to the cruise control has a t and one side has a bolt in it. Also there is a plug in the harness that runs along the firewall. It is not connected to anything.

 

Anytime I want to "look" for a vacuum leak, I carefully go around the intake with short little bursts of starting fluid. If you hit one the sound of the engine will change.(my Jeep had a bad one at a lower injector O ring). I see the question mark in your attachment title. My FPR is right on the end of the rail, with one vac line going directly to the manifold. It would be the last place, (after the check valve, injectors, or the lines themselves), where your pressure could get away.

Does it start better with the new plugs?

 

It doesn't start any easier really. I know where the fuel pressure regulator is. Mine looks different than all the ones on the parts store websites. Its shorter. Any idea what the plug and vacuum line is supposed to go to?

 

No. Pretty sure mine has a plug in a line near the EGR valve. Also I'm not sure all the lines to my heated air flapper deal in my air cleaner are all hooked up. I just mention those because it seems to run fine without them.