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Alan Brase
Samba Member
Joined: March 28, 2004
Posts: 4570
Location: Cedar Falls, Iowa
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 Posted: Sat May 13, 2023 6:10 pm Post subject: Re: '86 Vanagon running way too rich |
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From 1990 to 2018, I drove 5 different 2.1 Vanagons about 300k miles. At least a THIRD of those miles with the sensor unhooked.
For the Digifant to work, one hqs to have a completely leak free exhaust system ahead of the Oxygen sensor. If there any leak, AIR will come into the system behind the pressure wave and the sensor sees this oxygen and adds more fuel to bring it right.
Mine were often leaky, so, pull the single signal wire.
Oh, sure, it will get 2-4 more mpg with the system perfect. It takes about 1 minute to pull the signal wire Leave the 2 wire connector hooked up.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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Ahwahnee
Samba Member
Joined: June 05, 2010
Posts: 10249
Location: Mt Lemmon, AZ
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| Posted: Sat May 13, 2023 10:01 pm Post subject: |
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| wehrbüchse wrote: |
| ...neither I nor the shop has tested the O2 wire through the harness back to the ECU.... |
And that is what you need to do. Sure sounds like a short to ground on that coax. If it is then unplugging the O2 isn't going to help. |
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Alan Brase
Samba Member
Joined: March 28, 2004
Posts: 4570
Location: Cedar Falls, Iowa
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| Posted: Sat May 13, 2023 11:21 pm Post subject: |
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| Ahwahnee wrote: |
| wehrbüchse wrote: |
| ...neither I nor the shop has tested the O2 wire through the harness back to the ECU.... |
And that is what you need to do. Sure sounds like a short to ground on that coax. If it is then unplugging the O2 isn't going to help. |
I guess I've been a Journeyman Electrician for 45 years. and been fixing automotive wiring at least 12 years before thqt.
My point being that very often, close inspection of the wiring will show physical damage.
Anotherpoint of failure is the harness grounds to the engine corrode off. This might CAUSE STARTER RETURN CURRENT thru the harness of a much greater magnitude than the thin harness wires could handle.
I've crimped eyelets on pieces of stranded AWG 10 and made extra engine to chassis grounds. Good automotive practice would be much finer/ more flexible straps, but home made worked okay.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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djkeev
Samba Moderator
Joined: September 30, 2007
Posts: 32989
Location: Reading Pennsylvania
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zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 3861
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| Posted: Sun May 14, 2023 7:33 am Post subject: Re: '86 Vanagon running way too rich |
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| djkeev wrote: |
If it were my uni........
I would first unbolt the catalytic convertor junction before the convertor. No need to fully separate the junction just make it loose and noisy.
Go for a ride.
My guess is you'll make it home ok.
Your convertor is plugged and the back pressure is causing poor running and then shutting down the combustion process.
If not..........
I'd switch in a set of new spark plugs.
I would then get a new temp II sensor and install it.
Dave |
If the catalyst is indeed bad, i.e. clogged, a visual inspection should show that, if you cant see light through it, then hollow it out, use a metal rod, screw driver, jack handle etc.. to punch out all the ceramic bits, then reinstall the hallowed out thing for a smooth quiet drive.
I have done that to get home, it works.
Of course confirm it is indeed clogged before gutting it.
And when ready for a new catalyst besure to check out and make correct the mixture so the new catalyst dont get ruined$$$$$$ The Van runs just fine with no catalyst, but wont pass smog test.
For a temp sensor, read the ohms value, test both hot and cold, and wiggle the wires on the sensor when testing to check for breaks. Ohms values are listed in the VW service book.
If you suspect spark issue, sure you can replace the plugs, but inspect them, they should all look the same on the bussiness end, if not that is a clue as to which cylinder has a problem, which might be the plug, the spark wires, the injector, compression, etc...
You can test the cap and spark wires with an ohm meter, rotor too.
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Sorry About That Chief.
Give Peace a Chance.
Words to live by. |
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djkeev
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Joined: September 30, 2007
Posts: 32989
Location: Reading Pennsylvania
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Alan Brase
Samba Member
Joined: March 28, 2004
Posts: 4570
Location: Cedar Falls, Iowa
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| Posted: Sun May 14, 2023 12:47 pm Post subject: Re: '86 Vanagon running way too rich |
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| djkeev wrote: |
How do you KNOW it is running rich?
If it were my unit........
I would first unbolt the catalytic convertor junction before the convertor. No need to fully separate the junction just make it loose and noisy.
Go for a ride.
My guess is you'll make it home ok.
Your convertor is plugged and the back pressure is causing poor running and then shutting down the combustion process.
....
Dave |
Oh, i LIKE this!
VERY possibly the same thing caused a cat meltdown.
if you have a bad temp sensor or oxygen sensor, and it is running very rich, it will ruin the catalytic converter, and possibly make it become plugged.
_________________
Al Brase
Projects: 67 sunroof bug, 67 Porsche 912 Targa, 70 Westy
Dec 1955 Single Cab pickup WANT 15" BUS RIMS dated 8/55, thru 12/55
To New owners: 1969 doublecab, 1971 Dormobile
Vanagons:
80 P27 Westy JUL 1979, 3rd oldest known US
83 1.6TD Vanagon, 87 Wolfie Westy daily driver, swap meet home |
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zerotofifty
Samba Member
Joined: December 27, 2003
Posts: 3861
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| Posted: Sun May 14, 2023 2:46 pm Post subject: Re: '86 Vanagon running way too rich, Stalling once warmed up |
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| djkeev wrote: |
Impossible to examine convertor when it is in place.
Creating an exhaust leak before the convertor will quickly tell you if it is plugged or not.
You could even unscrew the test plug but the cap often falls apart upon removal. |
Well, yeah duh. So remove the catalyst and look through it into the light, if clogged then clean it out.
Sure test it by loosening the inlet and pulling it back far enough to allow gasses to escape before catalyst, and it that helps her run, the catalyst is likely clogged (the muffler might be clogged however) , then pull the cat and clean it out if clogged. button it all back up and drive in quiet bliss.
Keep in mind that if you run with the clogged cataylst, but only pull the inlet open to allow her to run, the oxygen sensor wont be in the exhaust stream any longer, so that wont work right, if however you clean out the catalyst, and reattach, then your oxygen sensor will be in the exhaust stream, and thus will function correctly.
_________________
Sorry About That Chief.
Give Peace a Chance.
Words to live by. |
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