Question - Fuel Distributor & Gaskets

[Tidybuoy]

I've been working on getting my CIS right, checking pressures, new WUR, fuel lines etc..

In the process, I noticed that the fuel distributor - actually the whole sensor plate assembly, is mounted to the airbox with screws that have springs under them. Mine looked loose and my 1st thought was that theses must not need to be super tight and maybe this whole thing is just sitting on top of the air box but not a critical seal.

After thinking about it, I decided to tighten up the screws and suddenly...my idle surge seems to have gone away.

This tells me that this is a source of vacuum leak and I'm wondering if it's possible to replace gaskets etc... Basically, I'm not sure what's under there and I don't want to start taking apart without knowing what I'm getting into first.

Any advice would be much appreciated.......Vern

[Tidybuoy]

Found everything - The PET catalog saves me everytime!

[rusnak]

I just noticed you're in Fresno. Have you ever had Tony work on your car? He's a wealth of information.

[timmy2]

Originally Posted by Tidybuoy

Found everything - The PET catalog saves me everytime!

Foam gasket under FD and airmeter assembly, o-ring under throttle body and 2 o-rings for CSV.
Make sure your rubber boot from TB to Metering plate is good and tight with no cracks in it.

[Scott R]

Tightening up the keyway gasket shouldn't have fixed anything. You can run the engine with airbox cover off and it would simulate the same condition. The large o-ring on the throttle body is a bit more critical however.

[Tidybuoy]

I used the PET catalog and made a list of every single gasket/o-ring that I have not already replaced. While I'm at it, I'm going to fix a few oil leaks so I looked up all that too.

I'm going to place an order with Pelican tonight when I get home from work - can't do it now.

[Tidybuoy]

Originally Posted by rusnak

I just noticed you're in Fresno. Have you ever had Tony work on your car? He's a wealth of information.

I'm not sure I know who Tony is - the only Tony I know is Maslowsky in the car club.

[boyt911sc]

Originally Posted by Tidybuoy

I've been working on getting my CIS right, checking pressures, new WUR, fuel lines etc..

In the process, I noticed that the fuel distributor - actually the whole sensor plate assembly, is mounted to the airbox with screws that have springs under them. Mine looked loose and my 1st thought was that theses must not need to be super tight and maybe this whole thing is just sitting on top of the air box but not a critical seal.

After thinking about it, I decided to tighten up the screws and suddenly...my idle surge seems to have gone away.

This tells me that this is a source of vacuum leak and I'm wondering if it's possible to replace gaskets etc... Basically, I'm not sure what's under there and I don't want to start taking apart without knowing what I'm getting into first.

Any advice would be much appreciated.......Vern

Vern,

Any air coming through the gap between air box and the air metering unit is simply unfiltered air. It has no effect or relation to your surging idle speed. And won't effect the mixture at all. The gasket between air box and air metering unit is made of light foam material.

Have you pressure tested your system (engine) to locate sources of air leaks? Then have the exhaust gas analyzed with a gas analyzer and set accordingly. Keep us posted.

Tony

[manbridge 74]

An interesting aside on the screws with springs underneath. I remember reading somewhere that the screw is tightened and backed off one turn. Not sure why.