Pulling Fuel Rails and Injectors

[A26B]

There is something odd going on that will need some clarification and/or photos.

1. Your signature indicates you have a 1995 ZR-1
2. Only 1990~92 models have the seal in the injector housing for the primary injector.
3. 1993~1995 LT5 engines have the same o-ring seal on both the top & bottom of all 16 injectors.

If your injector housings have an o-ring seal in the primary injector bore, then you have either early injector housings on a late model engine (replaced at some point after manufacture) or the engine has been replaced with a 90~92 model.

You ordered the 93~95 pkg which would not include the lower seal for the primary injector, PN 10067600-V.

A note regarding re-use of original fuel system seals
I am opposed to re-using the original o-ring seals, especially in the fuel system, regardless of how careful one is or how good they might appear to be. I have never been able to determine what material the original seals were made from, so compatibility with modern, ethanol blended gasoline is questionable. Regardless of the compatibility issue, original seals are now at least 19 years old. The seals take a "set" and also do not have the compressibility as when new. For the small difference in expense, it's simply not worth it to risk a fuel leak or trying to hunt down an difficult vacuum leak (in the case of the lower injector seal).

[KJL]

Wow, OK, it looks like I need to do some checking. I guess the first question to ask is are they interchangeable? I noticed looking into the injector bores, they don't line up well with the heads. It is not a smooth transition between the injector housing and the head. There is a "shelf".

How do I identify the engine as being a 95? I know I have the Dunn heads on each side. Not sure if that means anything.

Perhaps I should start a new thread to get to the bottom of this. I will also contact the previous owner.

[A26B]

Originally Posted by KJL

Wow, OK, it looks like I need to do some checking. I guess the first question to ask is are they interchangeable? I noticed looking into the injector bores, they don't line up well with the heads. It is not a smooth transition between the injector housing and the head. There is a "shelf".

How do I identify the engine as being a 95? I know I have the Dunn heads on each side. Not sure if that means anything.

Perhaps I should start a new thread to get to the bottom of this. I will also contact the previous owner.

This is your thread and the question you ask are relative in my opinion, so using this thread is appropriate.

Here is a link to an article I wrote regarding the different styles of Injector Housings, that you can download for free. It will allow you to identify exactly which injector housings are on your LT5.
http://jerrysgaskets.com/store2/root...roducts_id=762

Dunn heads were ONLY installed on some 94(very few)~95 engines. The most definitive way to determine 90~92 375hp from 93~95 405hp engines is to look at the bottom, LH driver side) corner of the front cover.

Here are links to the gaskets so you can see the difference.

http://jerrysgaskets.com/store2/root...products_id=14

http://jerrysgaskets.com/store2/root...products_id=15

The gasket photo for the 405 hp is reversed as viewed from the front of the engine, but you get the idea, curved (early), vs square (late).

[KJL]

Thanks for the great info. Regardless of outcome, do you sell just the injector seals for the housing? It appears the housing to head and plenum gaskets for 95 that I already purchased should work?

[A26B]

Yes I do, PN 10067600

[A26B]

This is an odd situation, so let's make absolutely sure what your situation is before ordering new seals. Review the Tech Data & confirm which housings you have. If you are still unsure, post a photo here or email to store@jerrysgaskets.com.

[KJL]

That is a good idea. I did some thread checking on the corvette forum from the person I purchased the car from and confirmed he used older model injector housing and plenum for powder coating purposes. I will check the engine out when I get home and also the part numbers.

[KJL]

Funny, the numbers on the housing do not match any of the numbers in the article but very close to number in housing picture for the 2nd design 1991 housing. My number is 10135836. The number in the picture looks to be 10135837, probably the other side.

I wonder why these numbers are not listed. Anyway I am certain it is an earlier version and the cover has the squared bottom corners.

The attached photo shows the shelf I spoke of earlier. I would have expected a better port match. Maybe it is not important as long as the injector housing port is bigger than the head port. It shows that fuel/oil collects on this shelf and that is what is seeping through the gasket and onto the head. It only happens when the car sits.

The other attachment is an inside view of IH.