1999 mk v6 3.0L mitsubishi triton

1999 Mitsubishi Triton

Car Problem

I just replaced spark plugs, leads, fuel filter, air filter, oil and filter, tappet cover gasket kit, timing kit with hydraulic tensioner , radiator , some parts at mechanics. When I drove it home it was weak on power but the mechanic said it mite need running in as the old parts were really bad. I done 24kms and used a quarter of a tank of fuel, it smelt fuely and was rough, when I went to start it the next day it would fire up it just backfires in the air box and exhaust like its misfiring, when I try to rev it, it dies like its getting no fuel or bad firing order or no air ,but the mechanic says he’s not sure to take it back and he will see if he can find whats wrong. Would u know please

Vehicle

Its a 1999 mk Mitsubishi 3.0L triton v6 manual 4×4
The fuel in old filter was black
I only done fuel filter, air n oil filters , radiator , pullys and fan belts , thermostat .
Mechanic done rest , plugs leads timing kit with hydraulic tensioner , tappet cover gasket kit
I’m getting a MAF air flow sensor tomorrow, could that be a possible problem or injectors


RESPONSE

The engines ignition timing is off. Probably one or two teeth off on the tinning. The timing belt was not double checked after installation.  A mechanic may get in a hurry and forget to rotate the engine 720 degrees and recheck the timing marks. This is a very common mistake. This should be covered under warranty by the mechanic if any was offered.