I have done a handful of timing belts without issue so this is mind boggling. Replaced the timing belt/water pump, tensioners, belts, spark plugs, valve cover, intake gaskets. 165k the truck was running fine before the service.

The engine will turn but will not run. Too much fuel in the cylinders. With the EFI relay pulled the motor will turn but when the relay is installed it acts like its backfiring causing the motor to not turn as easy.

Checked timing 3 times, I'm confident it is spot on.

Checked spark on all plugs, changed out wires.

Let the truck sit over night to be sure the built up fuel in the cylinders is gone but as soon as I go to turn the motor on it soaks the spark plugs.

No check engine light codes.

Did you check codes? Can't have a light without it running. If you have a cam sensor code, check the reluctor ring on the crank, if you broke a tooth, it would give it a retarded timing, by about 36 degrees.

No codes unfortunately.

Electrical connections specifically the one behind the passenger side of the backside of the camshaft cover or the camshaft sensor?

Cam or crankshaft sensor plugged in?

Unless he turned the cams after removing the belt, it doesn't matter what stroke it was in.

Sounds like something isn't plugged in.

Make sure the ground on the manifold is tight.

Even if he did, it doesn't matter. The valves time up by how the marks are set. Unlike old distributor motors, where you could put it together 180° out of phase, the ignition timing sets by the crankshaft and camshaft sensors, so if you spun an extra turn on the crank, the ECM sees that and no problem. Same for the cams, except that if the mark is at 12, then it is on compression on #1 no matter what. So just not a mistake you can make on this motor.

Check ground and sensor connections as suuggested above. Also, a common mistake is plug wire routing, check against this pic:



Are you sure you put the key in the crank sprocket? That's been done. Then it all looks right, but everything is out of time.

I know you said you checked it, and its in, but the bolded section sounds a lot like the timing is off. sounds like its firing when the piston is on the way up.

Which part of the TB job is that?

Yessir, we put the key in.

You don't HAVE to pull the crank sprocket to do the belt. You do if you also do the crank seal, which a lot of people do. Some people pull it just because it's loose on there once the pulley is off.

What is safest way to pull it without key or seal damage?

Usually by hand works just fine. If need be, spray some Kroil between it and the crank snout and then lightly tap it with a rock or jeweler's hammer.

Changing the crank seal should take tops 15 minutes with the right tools. The cam seals, a little bit harder.

Yeah, mine just slid right off with the pulley. Be very careful, those little teeth are brittle and you lose one and it's scrap metal. Each one feeds the sensor.