im questioning whether my precision 780cc injectors are true 780cc (having fuel problems on the dyno). so it was suggested that i put in some RC550cc injectors in their place and see if that corrects the problem. however, the RC injectors do not fit in the intake manifold like my old precision injectors did. i ended up having to take out the factory spacers out from under my BDL fuel rail to get the RC injectors to even come close to working. However, the gasket on the RC injectors does not fit into the intake manifold like the gasket on my precisions did. im having to literally sit the gasket on the top port of the intake manifold and sandwhich the injector inbetween the fuel rail/intake. here are a couple of pictures to help show whats going on.



as you can see, the gasket on the precision injector (right) has a 2nd gasket that sits into the intake. on the left, the rc injector lacks a 2nd gasket. ive tried taking the 2nd gasket off the precision inject and placed it on the rc, however, this will not sit into the intake manifold (too large of a diameter).



here are the two injectors sitting in the intake manifold. as you can see, on the precision injector, the 2nd gasket sits in the intake manifold. with the rc, i have to sandwhich the injector with the fuel rail to get it to stay. is this normal with rc injectors? do i need to purchase another gasket kit?

 

oh and the number on the precision injector is 7867/5 1125. does this give any insight on what size injectors these are?

 

ive seen small plastic spacers that fit in the injector hole, along with a taller (than you have pictured) rubber spacer gromet on top of that. <-- oem stuff.

perhaps you can stop by your local autoparts store to see what they have in stock. i belive they sell these things in little kits, that will come with a selection of "spacer grommets" or whatever the hell they are called.

 

put the gasket in the intake first, put the injectors into the rail then install the rail. the RCs sit on top of the IM gasket to seal. just make sure they are centered as you tighten the fuel rail.

EDIT: here's a link to download the .doc of the intructions from RC http://www.mediafire.com/?m2u0mmgiumn


Modified by dpetro1 at 5:39 PM 7/3/2008


Modified by dpetro1 at 5:40 PM 7/3/2008

 

great, that makes a lot more sense then how i tried to put them in. thanks, thats a big help.


can anyone answer if the numbers on the injectors have any relation to what size they are?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Origin &raquo;</TD></TR><TR><TD CLASS="quote">great, that makes a lot more sense then how i tried to put them in. thanks, thats a big help.


can anyone answer if the numbers on the injectors have any relation to what size they are?</TD></TR></TABLE>

Call precision directly for identification support.
FIY: Do you have a resistor box properly wired up ?

 

yes 99% sure it is wired correctly.

and thanks, should have thought to call precision originally.