Idle Adjustment O ring&Washer

**Kipp** · #1 (**permalink**) 02-03-2004, 12:20 AM

Somebody in my spiders history (Service Station mechanic) made the O ring out of silicone. Thay are so cheap and so easy to get, go figure why? The Alfa never ran correctly, it would cut out like it had a intake leak that I never could find. One day I just thought that I should check and see how old the O ring was doing looking for cracks, old age and found the silicone and no washer. After I put the new O ring and washer in, it cut out no more.
I was wondering how many out there are missing the washer? I have spoken to some Alfa Spica owners and some have it and some not.

**Roadtrip** · #2 (**permalink**) 02-03-2004, 07:38 AM

When you say it "cut out," do you mean it had a miss, varying idle speed, rough idle, etc? Was it only at idle or off-idle as well? What was your idle speed with the silicon 0-ring?

**Kipp** · #3 (**permalink**) 02-03-2004, 04:20 PM

The Idle speed showed almost no change. (very hard to notice) After putting in the new O ring. It is hard to see much of any change with this adjustment any way.
The symptom was more like cutting out. I never noticed it at idle, just from around 2000 to 3000 RPM. It doesn`t do it anylonger so I can`t go back and check to be sure. I know this being an idle adjustment seems strange that it had a larger effect on the off idle.

**Roadtrip** · #4 (**permalink**) 02-03-2004, 08:07 PM

It shouldn't have any affect off-idle since very very little air is coming in through the idle air system off idle. I was having an inconsistent miss under engine load as well as throttle blipping. I put a induction timing light on the wire and sure enough it was a spark plug wire that was bad and bleeding all over. Visually the wire looked good. A new set of wire cured that problem instantly.

MrT · #5 (**permalink**) 03-11-2004, 07:52 PM

I had no such O-ring in the '86 Spider I purchased, at least so far as I can find. The loose fitting was a source of unmetered air leak until I fixed it. But I had to go to an Alfa supplier for the proper O-ring. Do you have a standard part no. or O-ring supplier spec for this ring? They were priced at $1.45 each plus S/H plus time delay, and it would have been much nicer to be able confidently to go to the hardware store around the block and get one in 10 minutes.

Is there a place where such tidbits of info are kept organized? I'm looking and have found denovich's pages and am considering posting some info I wish I hadn't had to generate myself.

Michael

**Roadtrip** · #6 (**permalink**) 03-11-2004, 09:46 PM

Michael - The above posts were referring to the SPICA injected Alfas, not the Bosch injected like yours. The SPICA system was replaced by the Bosch L-Jet system in '82.

MrT · #7 (**permalink**) 03-11-2004, 10:09 PM

I found the Bosch system to have an idle adjust bypass hose with adjustable restriction consisting of a brass nozzle screwed up against a seat and held in place by a jam nut. As delivered, the Bosch fitting was loose and leaking air into the intake plenum. No o-ring in evidence. Bad ju-ju, from what I have learned.

I had some stuff to order from IAP. I had not looked at the Spica system for this issue, and rather than going into the garage to look, I asked and was told, "Yes, the Spica has an identical o-ring idle adjustment." So I have two o-rings from IAP. I'll look sometime soon, probably after the '86 clutch pivot and flex hose issues are settled and the engine is smoothly running.

Michael