do I need a new gasket

[Tremblor]

If im going to pull off my throttle body and my fuel rails, should i replace the gasket under the throttle body? Also, my 4.0L has seperate fuel rails, and the one i pulled the injectors out of had the fuel rails built right into the intake manifold. Are both of these injectors going to be the same?

 

[Anime]

Yes, the throttle body gasket is a very inexpensive part, maybe just a buck or two if that, and will seal it from any air leaks.

All 6 injectors on the 4.0L, like most engines, are the same.

Be sure to get 6 new O-rings for the injectors when you put them back in.

 

[Tremblor]

alright, the problem i'm having is the guys at the parts store are telling me the gasket for my throttle body is 66$ and its cheaper to get the head rebuild kit for 122$ and it comes with all the gaskets... they are trying to screw me in my own opinion... and i can't seem to track down the throttle body gasket on its own for a couple bucks...

Found an independently owned parts store that found me the throttle body gasket for 3$ and injector seal kits for 10$ a piece. I'll pick them up tomorrow and do the work on the weekend, it's -15 degrees right now and it's gonna be +9 on the weekend so i'll wait till then and give you guys an update. Thanks a lot for the info.

 

[Maniak]

alright, the problem i'm having is the guys at the parts store are telling me the gasket for my throttle body is 66$ and its cheaper to get the head rebuild kit for 122$ and it comes with all the gaskets... they are trying to screw me in my own opinion... and i can't seem to track down the throttle body gasket on its own for a couple bucks...

Found an independently owned parts store that found me the throttle body gasket for 3$ and injector seal kits for 10$ a piece. I'll pick them up tomorrow and do the work on the weekend, it's -15 degrees right now and it's gonna be +9 on the weekend so i'll wait till then and give you guys an update. Thanks a lot for the info.

I think we are mixing terms...

The throttle body is the thing with the butterfly that is at the front of the upper intake plenum.. That gasket is FEL-PRO Part # 60886 and is < $2

The throttle body is connected to the upper intake. The upper intake is on top of the fuel rail which is on top of the lower intake.

The fuel rail is bolted to the lower intake with studs (external torx)

It sounds like you need an upper intake manifold gasket set. I don't remember buying "only" an upper intake gasket set. The upper/lower set combo is FEL-PRO Part # MS94682 and is about $30

~Mark

 

[Tremblor]

Problem solved

 

[Tremblor]

do you know what size those external torx are? i will need to purchase that tool as i have no set that contains it.

 

[Maniak]

I do not remember what size it was.. I bought a set of external torx which is also called external star sockets from harborfreight tools. I think I paid $6 for the set.. worth every penny..

~Mark

 

[Tremblor]

ok awesome. i'll check my local canadian tire or lordco for a set of those. anything else i should know before doing my injectors?

 

[Maniak]

Lube the o-rings before you install them. I use non petrolium (sp?) based oil (peanut oil actually) to lube them.

Also, If you do end up taking off the lower intake.. install the injectors and fuel rail to the lower intake before you reinstall the lower intake on the motor. It is so much easier to get everything lined up (injectors etc) when your not awkwardly leaning over the engine.

~Mark

 

[Tremblor]

I don't have to remove the lower intake manifold to redo the injectors though do I? I just have to pull the external torx and lift the fuel rail off... are there seperate bolts that hold the lower intake on, or do the torx hold the rails and the lower intake on?

 

[Maniak]

If you just trying to do the injectors, then you have the right idea..

Leave the lower intake connected.. and it does have separate bolts that hold the lower intake on.. Soo, once you get the external torx bolts off and pull the fuel rail off, stop taking things off.

~Mark

 

[Tremblor]

Ok, thanks a lot Maniak. You've been a ton of help. I will conquer this injector on the weekend when it warms up.

 

[Tony H]

http://www.thetoolwarehouse.net/p-3049-lisle-26750.aspx

For some reason E-7 sticks in my head for the correct size

 

[sjdurb]

Maniak, I've been reading other threads that talk about this whole process and they recommend vasoline for the fuel injector O-Rings, which is clearly petroleum based... what's your opinion on that? Would I use the same lubricant on throttle body o-ring/gaskets?

 

[Tony H]

KY jelly, serious... non petroleum and enough lube to get them seated in the Manifolds. I have just licked the 'o' rings...It lubes them enough to help them in the holes.
'They' say that petrolium based products deteriorate the rubber 'O' rings. I think it's bunk. Gas wont bother them but other petrolium products will??

After the Injectors are in the lower manifold, you can take the upper rail and tilt it so the back injectors start to seat first, then lower the front wiggling the injectors in as you lower it.

 

[Maniak]

Basically, "its the way I was taught". And some o-rings I've used (not for injectors) didn't last long when I used to use engine oil to lubricate them.

If it says use a petroleum based lubricant then it shouldn't matter. I just use non petroleum based oil on any o-ring now when I install them since I don't know if they all have the issues or not.

~Mark