Thread: Need some info on injector o-rings

Seems I've got a vacuum leak coming from a couple of injectors on the back side. I'm running green top 42's on an 06 L32, so do I get Ford or stock GTP o-rings? and is there a difference in size from top and bottom rings?--noticed that Rock Auto has a set of 06 L32's that has blue and black o-rings from AC Delco that look the same size but Mahle has different part #'s for upper/lower and pic shows that lower seem thinner. If I need Ford orings, anyone have a part number? Thanks

link to Rockauto orings: http://www.rockauto.com/en/catalog/p...r+o-ring,13679

they are not the same size top and bottom o rings, i got the lower felpro o rings from auto zone for like 8 bucks iirc. not sure if you need ford or gm injectors rings tho. for 8 bucks its worth a shot tho.

pretty sure i used the magnum lim kits o rings on my 42's as well. they would have been for a l67 of course.

Thanks for the reply! Are the thicker ones for the rail and thinner the manifold? I've been to many sights that seem to be conflicting on their info... some have top and bottom as being the thicker ones while others show the 2 different sizes.

pretty sure the top set are larger.

cut your old ones off with a sharp razor, if you try to roll them off the tips tend to break off. then oil the new o rings and roll them on.

make sure the injector holes in the lim are clean, i used Q tips and sprayed brake cleaner into the cap then dip the q tips and wipe the injectors out. might need a lot of q tips, i went through maybe 30 of em.

then make sure the o rings are lubed with oil, and push them back in the lim.

Thanks for the tips. I just steamed the motor last week in preparation for this so hopefully not too much gunk still in the wells. I always cut the orings off as well, nothing like busting one of the caps to start things off!

Bought a set of Felpro orings that Napa had listed for the supercharged applications, one for rail end (#es70599) (thicker) and one for manifold end (#71190) (thinner). No way the thinner ones are for s/c injectors, the inside diameter is too big and they would be like a pencil dick trying to use a magnum condom--ain't going to happen! I take it the thinner orings are for non s/c injectors which have a thicker neck on the cylinder head end on them.

On a side note... figured out why my injectors aren't sealing... turns out that the middle injector cap on the back rail isn't on as much of an angle as the outer ones (factory flaw?), and I guess as the o-rings have hardened up over the years it took away any extra tolerance they had for trying to seal up the extra pressure being exerted on the injectors. Not sure how to fix this other than a new rail, can these be bent into position, even slightly, without cracking the welds? I'd post pics but too lazy to find new pic hosting site now that photobucket sucks.