Weird problem, anyone had that?
 

OK, trying to repair the car of a friend.

The car is hard to start, no matter if it is hot or cold, it is hard to start.

Also, he says that when he its the gas (once he finally got it started), after 5000 RPM at WOT, he gets a lot of backfire.

He just had the injectors cleaned and the fuel pressure seems fine.

Anyone know what it could be? he changed the spark plugs also.

Igniter? coils?

anything else?

the car just received a rebuilt engine, could there be a problem with the crank angle sensor?

thanks a lot

puma