If everything checks out AFTER YOU TEST IT (Trust, but verify) I would be intersted in taking off the timing cover and seeing whats up.
THose arent the wrogn injectors! The lucas ones are shit fromt he factory. The ford ones are superior in design.
Overheating, low vaccum... COULD be a leaking intake.
Did he check firing order?
Did the check the spark plugs?
Did he check the spark Qaulity?
Did he check compression?
Test..Dont guess! I gave you the proceedure. DO that before hunting down the timing chain.
Linder Technical Services - Automotive Solutions for Today's Technicians
Dont take my word for it, as these guys. Fuel injection GODS as far as I'm concerned.
Here. Read page 2 of 4.
http://www.lindertech.com/newsletters/nwk3~04.pdf