99 ram missfire

I have a 99 ram that has been giving me a little trouble with a misfire. It only does it for 5 minutes or so when I first start it on a cold start. It has new plugs, Mopar wires, cap, rotor, plenum plate and intake gasket, thermostat, etc., etc. The first time I had an issue I found a cracked plug on #8, now I had a misfire on #7. I haven't checked compression yet. I do think I may have an injector issue, 2-3 times I've started it and have smelled gas bad for about 10 seconds. Also has a new map on it. I'd like to find out whats wrong and repair it without throwing a bunch of new parts at it.

Is it going through coolant? What part of the the plug was cracked? If it's the porcelain around the electrode on the combustion chamber side you are probably looking at a cracked head. You won't pull off a 98 and up mag head that ain't cracked but yours may be bad enough to get coolant in the cylinder causing a miss till it warms up.

Not losing any coolant.

Plug was cracked around the electrode

The best way to tell if you have a head issue is to put compressed air into the suspect cylinder. Do this with the rocker arms off and the radiator full to the top. With the radiator cap off watch for the radiator level to rise with compressed air applied. If it rises and overflows you have a problem with the head or head gasket.

I'm going to purchase a camera to go into the cylinder so I can see if I have any kind of mechanical issue. If that goes well I'll pull injector rail and check injectors. It's just annoying. I'll also do a compression check as well.

Swap that injector into another hole and see if the miss follows it. Easiest way to check.

I had the exact same symptoms on a Mazda; smelled gas and had misfire codes. The cause was bad injector seals. Try what Guitar Jones suggested...

Done a bunch of testing today, I found another champion plug cracked. Switched out all 8 plugs with a new set of autolite's. Misfire has been solved.

Next time go NGK,IMO. I just recently had a set of newer autolites cause miss fires. Put in my favorite NGK plug 7 weeks ago and all is well again ever since.