Seand12

New to the site thanks for any help guys!
Here goes,, moms jeep, a while back she chunked a piston, the head turned out to be junk so I threw in a 4.0 I had that ran great from a 1996. My question is this, I'm having an intermittent missfire under load on cylinder 3 and 1. I should mention I went with the viper coil mod as the 96 head had no mount points for the coil rail and I didn't want to mess with homemade brackets anyways.
I have the same missfire with the viper coil verses coil rail so I don't believe the problem lies there. im looking hard at the injectors as my compression and fuel pressure look great. My question is this,, I'm finding thread after conflicting thread on which injector upgrade will work for this engine, some posts say 1998 to 2004 others say 1997 on down. Is the fuel pressure the only concern here or is there a mounting issue, engine difference I'm unaware of? What injector should I go with for basic stock running and who would you recommend I buy from? Thank you for your time!

Ralph77

So you say you used the head on the '96 motor and guessing with the '01 exhaust manifolds.
Did you use the adapter plate?

https://jeepexhaustadapter.com/

Dave51

Did you pull and clean them?

Seand12

I didnt notice an appreciative difference in mounting of the different exhaust and did not use an adapter plate.

Seand12

not yet, weather was terrible and other than the shaterd piston she ran fine so I gambled the injectors would still be fine, #4 was the piston that went and my missfire is on cylinder 3