ok...so I was looking online at injectors because I think my 7 needs a new one and I noticed something about primary and secondary injectors. WTF? I only see 2...I dont know where either is located and if the ones Im seeing are the primary or secondary...



this is confusing. lol



I asked my dad and he said more than likely one set is direct injection...I know what that means...but where IS it injected?



could someone please tell me how this system works as-well?

 

there is a set of injectors under the UIM, they are hard to see with a stock motor.

 

thank you!!



that's a very nice setup you have there...



so, how exactly does this system work? I'm trying to learn...also trying to diagnose a bad idle problem

 

The primary injectors are in constant use, and sufficient for low load conditions. Above 3500 RPM and under heavy load, the secondary injectors add more fuel. Pretty much analogous to the primary and secondary barrels on a 4-barrel carburetor.

 

cool...I get it now. now I need to get or make a noid light and test my injectors...I think I have a VERY bad injector...or bad seal somewhere...cause below 1k rpm, the car SHAKES...so, I need to figure out whats-up with it...





thank you dudes for the immediate response...lol