I have a set of extra rings, and I almost threw out my old injectors away, I am glad I didnt now.
Ill double check for lines that are disconnected but I spent like 45 minutes checking and double checking everything in the area.
It ran and accelerated fine, it just had a hard start issue, which could also be linked to this as well.
It sounds like to me that there is a sensor issue, or a fuel delivery issue unless the coil is arcing at high rpms, which it doesnt appear to.
My first hypothesis of the need for more fuel at higher rpms due to the injectors and bigger throttle body still seems like a viable option at this point..but I have had my Jeep to the floor at highway speeds with no hitch, shudder, or backfire or anything. I can almost guarantee that the same amount of fuel is needed there at 4500 rpm as now at 25-3000 rpm.
Its not really in my budget to replace the fuel pump right now, but if I have to I have to.

 

Rent a fuel pressure gauge. Don't start blindly throwing money at it. I've been down that road only find out later it was something stupid that should have been a free fix.

 

yeah, I agree.
I think that I will try to get this thing over to Advanced to see if they can pull any codes, and get a fuel pressure regulator.
I think I have a spare TPS somewhere I might try to swap out.
I know the MAP sensor is on the throttle body, but which vacuum corresponds with it?

 

This fuel pressure regulator you speak of, where do you think it is?

My '97 has it's regulator built onto the top of the fuel pump- not really an easy replacement. I don't know if the '99 is different, but if it is I wanted to know more about it.

 

99 is same as 97

 

93 was the last year for a ballast resistor. My 94 XJ (since sold) did not have one,while my 93 did. 3JeepGuy

 

A few updates.
I took the Jeep to get the codes pulled.
It came back with 3, all relating to the TPS even though before I went to have the codes pulled I put in a different TPS.
I dont remember the codes off the top of my head but it was low voltage to the TPS, and cylinders 1 and 2 had low voltage or something.
I bought a new TPS and changed it on the spot. The code went away, but the issue of bogging down and backfiring at anything over half throttle is still is there.
I tested the fuel pressure and it was about 48 at idle, and dropped down to the mid 30s at full throttle. I dont know if that is normal, but Id imagine it is because the fuel is leaving the rail much quicker.
I then ohmed all the injectors again and they were all the same.
So I am basically at the same place I was at before, only this time with no check engine lights, and a new TPS.

 

Maybe it's time to try swapping the stock injectors back in?

 

that may be my next step, I just dont have time to do so before work.
I will try to crank that out tonight.
I just dont see how those injectors would cause all these problems when I know people that run them with no issues at all.

 

Just because the ohms are within spec of each other doesn't mean they are flowing properly. I would yank them out and clean them.

 

I cleaned them thoroughly and did something like this months ago, however they have been sitting in a bag in my shop, so if all else fails I will try cleaning them again.

 

Never hurts. You could also try pulling the plugs off them one at a time and giving it some throttle.

 

yeah I did that too, it it just seemed to miss more at idle.
I switched the one and 2 and the 5 and 6 wires too and it made the idle worse.
Currently at idle there is an ever so slight miss (it may just be how the 4.0 idles) but when you do any of those things there is a very noticeable miss.

 

Another update: on the way to work my volt gauge dropped to nothing and the check gauge light came on..could all this be because or a voltage problem? There is no other engine lights present

 

Sure. Voltage has a lot to do with how a vehicle runs. Not enough of it and sensor might not give the right signals, fuel injectors might not trigger, fuel pump might slow down, spark might not be a strong... and the list goes on.

I will tell you, when I tested my fuel pressure a couple weeks ago it never dropped below 45psi while running, idle or otherwise. I was using a very high quality pressure gauge too.

Oh, and the problem you incountered today, that sounds like a bad connection- ground maybe?