To remove the intake manifold, do you have to remove the injectors and fuel rails? I just want to know in case I find I have to reseal the intake (oil leak).

 

Yes, just simply unbolt the fuel rails. Then pull the rails and injectors off, set to the side, and pull the intake. You don't even have to disconnect the fuel lines to the fuel rail.

 

Strick,

I just installed a new intake on my 92 (PurpleC4). For all the frustration that everyone has with the LT1 and some of the design features (Opti, Water Pump, etc.) the design of the LT1 intake makes up for it. As STL94LT1 has indicated, just unclip the injector connectors, unbolt the fuel rails, gently pry the injectors out of the intake, then swing the fuel rails over to the side, leaving the fuel rails, injectors, and lines connected.

Disconnect the wiring harness from the coil, TPS, IAC, Opti, etc. and lift it up and out of the way. Don't forget that there is a ground strap connected to the front of the passenger side head.

If you haven't done a TB bypass, then I recommend you just remove the 4 front mounting bolts and let the TB hang loose. This will eliminate you even having to drain coolant.

Here's wher having an LT1 is great....... No coolant passages in the intake ~ so you don't need to drain and refill the system. Also, no distributor to pull then replace (i.e no need for base timing setup).

It's fairly straight forward. Make sure you really rough up the end rails with a coarse emery cloth then remove all dust. I use a product called "Goof Off" to clean oils and greases. Use a high quality Permatex (silicone) to seal the rails and use plenty of it (especially in the corners).

Good luck. This cured my leak and now my garage floor is spotless.

~ Purp

 

Hey Purp, Thanks man. I remember back when I did my timing cover oil seal replacements, that I was having a hard time removing the injectors from the intake. So, I just realized that I really didn't have to remove the intake and left it alone. Do they just pull out? Is there a special tool to help pull them out with out breaking anything?

Thanks again

 

Strick,

If you leave them clipped to the fuel rail you can gently pry underneath the fuel rail (between the fuel rail and the top of the intake) and they will pop right out. I would bet that the o-rings are hard and brittle (and most likely have taken a set due to the heat and compression). Getting the injectors out of the rails is a bit harder because first you need to slide the locking clip away from the slot in the top of the injector, then wiggle, twist, and pull the injector. They will come out eventually.

You can buy a set of O-rings from GM for about $20.00 ( :eek: ) or you can take one of the injector and go to a local "King Bearing, Bearings Inc. etc." and pay 20 cents each. Remember ~ you will need to buy 16 but at that price buy a couple extra. They will measure the size and cross section of the o-ring for you and give you the right one.

I recommend you replace them. Don't forget that the upper o-ring (fuel rail side) seals fuel line pressure but the lower ones (intake side) seal against vacuum ~ an often overlooked source of vacuum leaks.

~ Purp

 

Hey Tom..as a note, be sure to put a little oil on the O rings on the reinstall. It is easy to "nick" them and that leads to a fuel leak. Ask me how I know. :D

Oh yea, if you do disconnect the fuel lines, do the same to the O rings in the quick disconnects.

 

To Purp and Steve, Thanks guys. This goes into my save file. :cheers:

 

Tom,

Let us know how it goes. You might as well buy a set of 24#/Hr. FMS injectors and install while you're at it! :thumbs:

~ Purp

 

And adjustable fuel pressure regulator. :)

 

What does this really do for me? Is it an adjustment I make all the time?

 

ok.. I disagree with the above.. you do not need to pull the fuel injectors or fuel rails off of the intake to get it off... I have take my intake off many times leaving them on.. relieve the fuel pressure at the scherderer valve, disconnect the fuel lines from the fuel rails, disconnect the AIR tube from the back of the manifold and remove the accelerator cable (and coolant hoses if you havent done the TB bypass yet) and unbold.. The only reason I wouldnt go this route is if you dont have the proper tool to remove the fuel lines from the rails (little plastic thingys) or you want to change out the injectors and or O-Rings..

Also, A new set of o-rings is included in the Felpro intake gasket set..

Hope that helps..

 

FWIW, when I replaced the intake gasket on my ole '92, I bought a gasket set from Pep Boys that had everything needed including the injector O-rings. Total price was ~$25. Might want to give them a call!

Oh, BTW, we replaced the gasket on OneDef's '92 in the parking lot at the Cruise In last year. Took about 2 hours. Gave us something to do! :lol: :D

 

Bought my intake set from GM and it didn't include O-rings ~ sorry for the bum information.

Here's my feedback on removing the injectors.....

After 12 years of heat and compression the o-rings could stand to be replaced. Why not? It only takes about 30 minutes more. As I said earlier ~ these represent 8 places where a vacuum leak can exist. I've seen it more than once.

My $.02 worth....

~ Purp

 

Excellent information from all of you. Thanks again. :cheers: Right now, I'm tooling up for my clutch/flywheel swap. I think I'll do the rear main seal while I'm there. After this project, THE INTAKE and maybe a CAM. :reddevil

 

on the other jand the FMS #24s DO include o rings.... :yesnod: