hi there, crashed my alt about a year ago ..put engine back in cant get it to rev pass 3000rpm then misses trc light keep flashing and some times back fires .put new air flowmeter in can any one help me please thanks

check your engine connections..

you havnt plugged in something.

Yep, sounds like you not put it all back together right

Ok, if its not going about 3k...
Check for codes,

If NO codes look at...
1) Fuel pimp
2) Fuel Filter
3) Ignition coils/leads and Spark plugs
4) All the o/2 sensors and CAT sensors

- Can you smell fuel not being burnt correctly.. at the exshaust side..

and most importantly .. are you using the same kind of engine.. with the same ECU

Edit

Iam guessing you have check the EARTHS on the engine.