My 94 seems to idle fine but when I give it throttle it bogs really bad. It started out as an occasional issue and has gotten progressively worse. So I pulled the expensive NGK plugs and put in some cheap autolite plugs as that seems to be whats recommended and the NGKs were black.... REALLY black! Could it be the coil is bad or would it be more of a fuel issue?

 

Yes.
If you have not done a proper tune up in a long time do it now. It seems to run rich.
replace or clean:
air filter
MAF sensor (clean with MAF sensor cleaner)
plugs, wires and coil pack
clean throttle body with throttle body cleaner
make sure the EGR system works properly.
Use techron fuel additive for a tank or two.

If you still have trouble after all that you may have leaking injectors.

 

Thanks a ton for the response! I did a tune up (plugs, wires, air filter) cleaned the throttle body and the MAF sensor but it's gotten so bad now that I can't even drive it. I also put in a bottle of heat. Hadn't really thought about the egr, what should I look for?

 

I brought the coil to work with me so I could test it. I was gonna bring the control module too but couldn't locate it on the truck.

 

Here is a quickie you can check.
Locate the fuel pressure regulator on the fuel rail, remove the vacuum hose from the top and no gas should come out. If it is wet or has gasoline coming out that will result in a rich condition cause some black smoke and it can affect your fuel mileage.

 

Well I just did a fuel pressure test and it had 30psi the book said it should have 30-45. I also checked the vac hose on the fpr and though it wasn't very snug it hadn't come off but there was some moisture in there. But once I was done with the test and put everything back she seems to run fine so somehow by checking the fuel pressure I fixed it?
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There should be no moisture or any kind of wettness in that line. Chances are the pressure regulator diaphram is leaking and may eventually come back to haunt you !
Keep a close eye on it.