3.0 backfiring an glowing cats

[Hatchetchubbee]

Have a 96 3.0 4x4 motor blew. Just swapped in another motor from a 94, so had to add the newer timing cover for crank sensor and had to drop in the cam sensor. Fired up ran not bad but constantly back fires crawled under to check for leaks and saw the cats glowing any ideas?

im wondering did i not get it at perfect TDC when i dropped in the cam syncro? the carnk is the 94 and the crance pully is the 96(with the sensor ring

 

[RonD]

Cats glowing means unburnt fuel is in the exhaust, so a cylinder is misfiring, check firing order again, then double check that, lol, I have mis-wired spark plugs many times over the years.
Back-firing means a cylinder is misfiring.
Don't run it too long that way, shut down and wait a bit for cats to cool down, until you find the problem.

If firing order is ok then I would pull the spark plugs and find the one that is not firing, could be a bad plug or wire.
Could even be a burnt exhaust valve so do a compression test on that cylinder.

Sure double check the syncro.
I doubt CKP sensor wheel would be different on any 3.0l.

 

[Hatchetchubbee]

after testing each cylinder compression and re gapping the plugs still nothin, but i did have my firing order screwed up..... runs like a champ now! thanks for the response

 

[RonD]

Nice work

I goof up the firing order more than I like to admit, firing order is a "no brainer", I seem to qualify quite well for the "no brain" things, lol.