O-rings, Backup Rings and W Pipes

[mluder]

Here's a silly question.

What order do the rubber o-ring and plastic backup ring go between the W-pipe and the butterfly assembly.
I recently took them apart and didn't pay attention how they were. I put them back with the plastic backup ring on the W-pipe first and then the O-ring (the O-ring is closest to the butterfly assembly). Now I have some sort of vacuum leak and I'm not certain if it's coming from there or somewhere else. I'd like to know if I put them back wrong before I take it all apart again. The parts manual would seem to indicate I did it wrong.
http://store.delorean.com/c-334-1-4-1-air-induction-system.aspx

Cheers
Steve

[Mike F]

You have the order right. It should be:

W-pipe -> spacer-> o-ring -> butterfly assembly.

You may not have a good seal where the pipe mates up to the intake manifold; where the paper gaskets go. I've experienced a slight leak there before, even with brand new gaskets. A little gasket sealant on the paper gasket before reassembly did the trick.

[Chris 16409]

My car didn't have the plastic rings. I don't think they are 100% required.

[David T]

My car didn't have the plastic rings. I don't think they are 100% required.

Refer to 1-4-1 in the Parts Manual. I think they ARE necessary. Maybe someone doubled up the "O" rings #53 instead of the plastic back-up rings? If the plastic rings are missing it means someone had their hands at least that far in. Now you have to wonder what else they didn't do right. BTW the "O" rings go on the W pipe first and then the back-up rings. Bolt #50 has to be tight but don't overtighten it or you will strip something.

[Gfrank]

Plastic back up rings are not required if missing.
The plastic back up rings go on the y pipe first then the o rings. Sugest lube