E7 454 injectors

[Brandon 1]

Hi guys, have just recently found this website and it looks awesome, im hoping i can get some help with my CH Mack Select, its a 98 model 454 v mack 2 

Since i bought it about 2 years ago it has had a bit of a miss and it seems to be related to air in the fuel system and maybe return fuel, you can bleed the air out of the system and it might run ok for a short period of time but always ends up with the air, its down on power and seems to be running a little warmer than it should.

We have tested many things including running a new fuel line directly in to the fuel tank to the lift pump and then a line directly into the main pump and it still did it.

Have had the pump tested and found ok, but when we removed the injectors we found that there were differences in the housings , some having return ports in a different place and some having an extra o ring groove.

my questions are ,

does anybody know why these differences and how many o rings should i be running on the  injectors , i believe the original injectors for this truck are the ones with the higher return port and the extra o ring groove, this truck had a badge on its hood saying High Swirl Injection.

Any help with this would be much appreciated, Thanks.

[fjh]

YOU NEED TO RUN THE TWO TOP ORINGS the  third oring can be used but is not necessary  if you study the injector a  bit you'll see that it doesn't mater if you use the bottom one its sealed at the tip by the steel washer! all of your injectors Should have a return hole that didn't change till early 2000

[Brandon 1]

Ok thanks  i will fit 6 of exactly the same I believe to be original style and give it a go , have only ever run the truck with three of each , remanufactured units that have come from the dealer here in Australia . 

I did not exchange the last set being suspicious of this so now have 6 of each style.