Idle Adjustment rubber o-ring

dpoole · #1 (**permalink**) 10-01-2007, 09:14 AM

Anyone know where to get the rubber o-ring that goes under the idle speed adjustment nut? If not, how about a suitable equivalent? I tried IAP and they don't have it.

I read an old posting that someone had just bought a standard rubber o-ring at a hardware store, but I don't know what size to get.

thanks.
'82 Spider w/ L-jet fuel injection

**ghnl** · #2 (**permalink**) 10-01-2007, 09:42 AM

I replaced that O-ring in our '84 Spider. I just took the old one to the hardware store and eyeballed a replacement. Works fine so far.

dghii · #3 (**permalink**) 10-01-2007, 09:52 AM

Home Depot worked for me.

dpoole · #4 (**permalink**) 10-22-2007, 07:24 AM

A big thank you to the BB, and I had a little luck (I hope). I was checking and cleaning all of the hose connections under the hood (as many no-start postings suggest). Prior to doing this it would start and run - after doing this it would not start at all.

I just got this Spider so I am going through the fuel system, etc. I started by removing the in-tank pump and of course that led to more "I might as well while I'm in there" tasks. So I took the tank out to clean it up and paint it; then I decided to spot treat some trunk rust with POR-15 and repaint the trunk, and so on.

Yesterday, I wanted to take advantage of the nice weather and the sun for drying out the trunk after final cleaning and hosing out (sorry I missed your open garage Eric but I'm eager to get my Spider running). So I rolled the car out about ten feet to get the trunk into the sun and I saw the rubber o-ring sitting on the floor of the garage! I guess it fell out during inpection and cleaning of the fittings.

Without this BB, I wouldn't have a clue where it came from and who knows what I would have gone through to trouble shoot the no-start. I don't have the fuel tank and pumps installed yet so I don't know for sure but I am hopeful that the no-start is the missing idle adjustment o-ring. Thank you BB's!

However, I need one favor. Anybody got a photo of the o-ring installed? I'm not sure if it goes directly in the intake plenum hole or between the two threaded brass fittings. Thanks.

**ghnl** · #5 (**permalink**) 10-22-2007, 07:47 AM

IIRC, it goes into the intake plenum with the brass fittings removed. As the brass fitting is then screwed back in place it will be compressed. How much it is compressed will cause the ID of the O-ring to vary thus 'adjusting' the idle speed as it varies how much air is allowed to enter.

carsdlt · #6 (**permalink**) 10-22-2007, 10:49 AM

Eric is right. BUT...make sure the o-ring is not hard - needs to be soft to compress and change size of orafice hole to regulate air flow. A hard, dried-out ring is the reason most are replaced. Good luck.

Also, if haven't done it yet, do a search under "L-Jet" and study the tutorial by Greg Gordon on tuning/troubleshooting your FI system.

**conedriver** · #7 (**permalink**) 10-22-2007, 01:37 PM

IAP part number 53400: "O-Ring, SPICA idle adjustment". The little picture in the on line catalog is incorrect, it really is the right O-ring.

Quote:

Originally Posted by dpoole

Anyone know where to get the rubber o-ring that goes under the idle speed adjustment nut? If not, how about a suitable equivalent? I tried IAP and they don't have it.

I read an old posting that someone had just bought a standard rubber o-ring at a hardware store, but I don't know what size to get.

thanks.
'82 Spider w/ L-jet fuel injection

**GuyC** · #8 (**permalink**) 10-22-2007, 08:05 PM

George are you sure this is the one for the L-jet ??

Quote:

Originally Posted by conedriver

IAP part number 53400: "O-Ring, SPICA idle adjustment". The little picture in the on line catalog is incorrect, it really is the right O-ring.

**conedriver** · #9 (**permalink**) 10-23-2007, 05:22 AM

Ooops... sorry, no. I didn't pay attention to the model year of your Spider. We SPICA enthusiasts sometimes think we know all of the answers.

Quote:

Originally Posted by GuyC

George are you sure this is the one for the L-jet ??

dpoole · #10 (**permalink**) 11-28-2007, 09:01 AM

Yippee! Finally got the fuel tank, new fuel pump & fuel filter all installed. Also installed the silicon trunk hose kit which is available from links on this site (great kit!). Added fresh gas, installed the throttle adjust rubber o-ring and tightened all the hose clamps under the hood - she started right up on the first turn of the key! What a great feeling to hear that sound the Alfa motor makes.

Next step is to replace the clutch pedal pivot arm so I can actually drive it (she didn't run when I got her so I have never been able to drive - can't wait!).

Again, thanks to this bulletin board. I would have never gotten to this point without this great resource.

D. Poole
Chapel Hill, NC
'82 Spider

**Tifosi** · #11 (**permalink**) 11-28-2007, 11:27 AM

Make sure to check the rod length on the clutch master cylinder while stuff is apart for the clutch pivot. (pix/dimensions in several locations through the forum) Your MS and slave will love you for it, and the clutch won't exactly be giving you fits either.

If you like the sound of the cold idle, wait til you hear it fully warmed up and spun into the higher rev ranges.

**ghnl** · #12 (**permalink**) 11-28-2007, 12:21 PM

Quote:

Originally Posted by Tifosi

Make sure to check the rod length on the clutch master cylinder while stuff is apart for the clutch pivot. (pix/dimensions in several locations through the forum)