tonight I took off my fuel rail to swap out my upper and middle plenums, and while the injectors were out I took a good look at them. A couple of them were cracked up by the tips, so I swapped those out with a couple I had from an extra engine I have


The question is, when I put them back in the engine, is there any kind of lube I need to put on the o-rings before I slide them into place, or for that matter should I replace the o-rings? They look good, but I'm not sure if I should replace them anyway

 

My Haynes manual calls out for a light film of motor oil on the injector o-rings (I just replaced all of mine). Have you checked their resistance while you have them out?

 

yeah I did.. all 12 were fine (two engines)

now a bigger problem. I swaped out a couple injectors from one rail to the other and I can't rememebr which ones I replaced in the new rail. My book says each injector is calibrated to go in a certain spot.

I've never heard of this before. when you replace injectrs, you buy 6 of the same kind, right? All the injectors are the same parts number, but the all have different codes on them, like 4A, 4B, ect.

But there's injectors in both rails that I know I didn't touch that don't even match each other (same engine)

this is so confusing

 

Yeah, that's unexpected. I bought all eight of the same kind of injector, no way to differentiate them by the markings (as far as I know).

 

Use vaseline on the orings during installation. And as far as im concerned they arent "callibrated", but dont take my word. My lucas 24 pounders didnt have any special instructions.

 

vaseline and stick 'em wherever you want 'em.

 

Thanks, after I posted this thread I found what I did with my GM service manual, and that's the book that said that each one is calibratred for a certain spot. BTW, it also said lubricate with motor oil

 

so what all is required to take off the fuel rail and install the injectors? do you have to disconnect any of the gas lines or can you just pop the rail off and throw the injectors in there?

 

I know you'll have to remove the metal line for the cold start, but you might be able to get way with not removing the fuel lines, but I'm not sure it's worth it. It will be so much easier to work on the rail if you can put it on a workbench or your lap. there are clips for each injector you have to rotate about 45 degrees, and that will free the injector and you pull the right out of the rail

 

sorry, I forgot to say you'll have to remove the upper plenum to get to the rail. Not a huge job, but there's a lot of bolts, and you might have to replace the gasket on each side when you put it back together

 

To pop the fuel rail off you'll have to disconnect two fuel fittings towards the front of the block. Pretty simple. Those fittings have o-rings.

Like he's saying the stock injectors have clips. We had my fuel rail on a bench pulling really hard on those things, even with the clips in the right direction.

So yeah, you'll need to disconnect two lines.