Explanation of broken O2 plug

[BlakeSmall]

I live in Texas and are only subject to safety inspection. I have SSI's, and no CAT, so there for I assume no oxygen sensor. From some things that ive read this broken piece in the left side of the engine bay, near the filter and accumulator is the O2 plug or part of the O2 sensor. Its starting to crumble however what purpose is this serving with the sensor being disconnected and should I worry about this or prepare to replace with some of the methods ive reviewed online. Most people seemed to need this functional for emmisions, but I dont.

So I just need an explanation of what I got and what this part is affecting or if it even is affecting anything anymore with the cat being removed. Car seems to be running fantastic. I did have a warm start problem that was solved with replacing the accumulator and now a few weeks after that I'm starting to develop a cold start problem and wondering if this could in any way be a cause.

thanks alot
-Blake

[Bob Kontak]

Originally Posted by BlakeSmall

I have SSI's, and no CAT, so there for I assume no oxygen sensor.

Hi Blake.

Get under the car and see if there is an O2 sensor screwed into your SSI's. There does not need to be a cat to have a functioning O2 sensor.

Also, why does the picture look like it's the passenger side of the engine bay?

The bracket that holds the harness is pop riveted. That ain't factory. Meaningless - but thems the facts.

[BlakeSmall]

Hi Bob... Jacked her up, and took a look. No sensor on the SSi's either. Came from a no emissions state aswell, where the SSi's and motor rebuild were done. Went ahead and took another pic from a further distance just to show you it was indeed the left rear side of the car. Looked at the bracket, and it sure looks factory, however I'm in no position to argue with you as I am learning these cars everyday, so Ill take your word on it.

Also while I got you on the hook, the fuel lines you'll see in this second picture had a rubber insulation wrap around the rubber/plastic fuel lines. The lines ive inspected and look in really good shape with the exception of the insulation which was terribly cracked and falling apart all over the place. I removed this on most lines where they were damaged the worst. Is this something that needs to be replaced? As badly damaged as they were they surely could not have been insulating much of anything anyhow. Never had any vapor lock type issues even in the 100+ degree heat of North Texas.?

Thanks for the help bud

-Blake

[boyt911sc]

Originally Posted by Bob Kontak

Hi Blake.

Get under the car and see if there is an O2 sensor screwed into your SSI's. There does not need to be a cat to have a functioning O2 sensor.

Also, why does the picture look like it's the passenger side of the engine bay?

The bracket that holds the harness is pop riveted. That ain't factory. Meaningless - but thems the facts.

Mr. Kontak,

Tilt your head to the left and look again at the picture. The picture shown is 90° off to the left. Everything looks good to me. So he has to run this late SC as a '78-'79 set-up.

Tony

[boyt911sc]

Is your '80 SC a USA or RoW model? Could you check the last 3 digits on your WUR? And measure the heating resistance (Ohms) across the WUR and could tell us something about your cold idle problem. Keep us posted.

Tony

[BlakeSmall]

Correct- I didnt bother to rotate as the picture was so close anyhow

[BlakeSmall]

on the cold start issue...Its not an idle problem its just a start problem...when its stone cold I need to crank the engine for maybe 3-5 seconds to start vs maybe .5 to 1 in all other situations...when it starts (stone cold) its stumbles for just a half second or so cleans up right away and idles/runs great. Ive placed an order with pelican for some testing supplies such as CIS test and I'm currently looking for a decent multimeter to purchase....Which I will need to learn to use. So im unable to give much data on that issue just yet.

Keep in mind I say stone cold....a stone in Texas right now is still prly *85 *90....Im just implying a First start of the day type deal...

[BlakeSmall]

1980 911 SC USA car I would certainly Imagine will the vin help you determine this. 91A0142181

[BlakeSmall]

last three on the WUR 072

[BlakeSmall]

I would guess whatever supplies the fuel for the cold start is having issues....CSV possibly...I certainly understand the value of the diagnostics tools and know we need to run through a check list to figure some of these little problems out...I'm still very fresh into 911 Ownership and acquiring related items by the day. Thanks for any insight guys.

[boyt911sc]

For a cold start you need 1 - 2 bar (15 - 30 psi) cold control fuel pressure, system fuel pressure between 65 - 75 psi., a good residual pressure, a good ignition spark and timing, a decent compression, a fully charged battery, and it should start provided you don't have excess unmetered air (vacuum leak).

All the above conditions could be checked and confirmed. Stop guessing and it would run. Guarantee!!!!

Tony

[BlakeSmall]

Thanks alot when my pressure gauge arrives next week maybe you can walk me through some of this. Ill keep you posted!

[BlakeSmall]

Also like I said. The car has run perfectly and starts every single time. Ive owned the car for maybe 40 days now?, and this problem has just recently, in the last 10 days started happening. Ive barely had the car long enough to know what tools/test supplies I even need, so I think its natural for someone to guess whats going on at this point. Reading up now on test procedures and things related to this injection system.

Any Ideas on the O2 Plug?

[boyt911sc]

Originally Posted by BlakeSmall

Also like I said. The car has run perfectly and starts every single time. Ive owned the car for maybe 40 days now?, and this problem has just recently, in the last 10 days started happening. Ive barely had the car long enough to know what tools/test supplies I even need, so I think its natural for someone to guess whats going on at this point. Reading up now on test procedures and things related to this injection system.

Any Ideas on the O2 Plug?

Blake,

If you are not utilizing the ECU for your engine, you don't need to worry about the OXS. Do you know if the car still has the ECU under the passenger seat? If you do, it would be wise to take advantage of the lambda system. But the decision is all yours.

Tony

[BlakeSmall]

Yes, the ECU is still under the seat. This is what made me think to ask about this. It seems the PO mentioned there was not an O2 sensor on the car however I saw the plug in the bay and its got me confused. I'm wondering if this sensor can be bypassed without causing issues and if so, is it by passed already or not? Is there any more info I can provide you with to get me further along on this subject?

Thanks Tony

[boyt911sc]

Originally Posted by BlakeSmall

Yes, the ECU is still under the seat. This is what made me think to ask about this. It seems the PO mentioned there was not an O2 sensor on the car however I saw the plug in the bay and its got me confused. I'm wondering if this sensor can be bypassed without causing issues and if so, is it by passed already or not? Is there any more info I can provide you with to get me further along on this subject?

Thanks Tony

Blake,

Your '80 SC USA comes with the lambda system and could be set to run without utilizing the lambda system by disabling the OXS and ECU. The '78-'79 have no OXS and ECU like the '80-'83. What the lambda system does is reduce the emission pollutants like carbon monoxide from the exhaust gas going into the environment. So if you are happy how the car runs now, I'll leave it as is for the meantime and enjoy driving it. One of the fastest and great running CIS track car in our region is an '83 SC less OXS and ECU.

Tony

[BlakeSmall]

10-4 thank you for the explanation, I will leave it as is.