Smoother without the lambda probe....

Thin bits of metal and bright blue light.

Moderators: User administrators, Moderators

Locked
User avatar
youde4
Registered user
Posts: 47
Joined: 27 Oct 2008, 13:29
80-90 Mem No: 7225
Location: Kingston upon Thames
Contact:

Smoother without the lambda probe....

Post by youde4 »

I've read many topics about the lambda probes and what not, and read that the engine wont run right without it plugged in (2.1 MV), however after some problems a few months back with running issues (lack of acceleration etc) i decided to unplug it and it ran much better without it. Its been disconnected for a few months now without any issues. (lambda was newish at the rime)

So, my question is why is it ok when everyone on here says it wont work without it? Surely an ecu this old wont have a safe mode? If anything theres a slight bit of hesitation with the first bit of revs but cant remember what it was like when all was running sweetly when i first bought it. It is rather gutless atm but i think that's due to the 205 80 16 MT's on it,

Anyone got any ideas because i think ill just leave it disconnected.....

jed the spread
Trader
Posts: 9020
Joined: 09 Oct 2005, 17:31
80-90 Mem No: 1967
Location: Sutton in'it Syncronaut: 123
Contact:

Re: Smoother without the lambda probe....

Post by jed the spread »

If its disconnected it will go into Limp Mode and you will get really rubbish MPG for starters. Put a Diesel in, that will sort out your problems

jed
CAMPERVANCULTURE.COM

VW T25 Van Spares, Westfalia Parts, Quality Camping Gear & More

User avatar
toomanytoys
Trader
Posts: 2868
Joined: 11 Oct 2005, 18:37
80-90 Mem No: 41
Location: Boston area, South Lincolnshire

Re: Smoother without the lambda probe....

Post by toomanytoys »

Oh shut up Jed.......

It will default to running richer to protect the cat and engine.. the ecu will default to the safe side on all adjustments it can make
any air leaks in the exhaust will cause poor running with lambda connected as its constantly trying to adjust to an incorrect reading.. any other fualts or missadjustments will not help either..
Aidan will prob be along with some good tips too as he has had a few running issues to sort in the past on the MV

Yes the 205r16 tyres will blunt the performance somewhat depending on what gearing you have....

jason k
Registered user
Posts: 938
Joined: 13 Nov 2005, 09:35
80-90 Mem No: 1959
Location: aberdare south wales

Re: Smoother without the lambda probe....

Post by jason k »

why not replace the dodgy sensor?
98 Westfalia James Cook

syncrosimon
Registered user
Posts: 570
Joined: 29 Jan 2007, 00:50
80-90 Mem No: 3784
Location: Blackdown Hills of Devon and Somerset
Contact:

Re: Smoother without the lambda probe....

Post by syncrosimon »

When you disconnect the lambda the ecu works like a DJ where the ecu uses look up tables to determine the fueling without the self correcting abilities of the lambda.

You will have a problem somewhere in the system and you need to trouble shoot the whole thing. Obvious faults indicate lambda shield wire grounding, spark plugs and wire faults, and coil faults.

Some suggestions here.
http://www.thesamba.com/vw/forum/viewto ... da&start=0

and here.
http://www.van-cafe.com/home/van/page_8 ... _tool.html

And download a copy of the pro training manual from here to work through the system.

http://www.westfaliat3.info/html/westfa ... loads.html
1991 16" DJ (sold)
2006 Subaru Outback 3.0R
2010 Yamaha Ténéré
2000 KTM LC400

User avatar
youde4
Registered user
Posts: 47
Joined: 27 Oct 2008, 13:29
80-90 Mem No: 7225
Location: Kingston upon Thames
Contact:

Re: Smoother without the lambda probe....

Post by youde4 »

It turned out that the sensor was a universal one and did not work well, i put the original back in that was supposedly nakered and it ran smooth. No flat spot any more, but mpg and performance wise id say it was no different to when it was unplugged.

Simon Baxter
Trader
Posts: 3116
Joined: 08 Oct 2005, 19:36
80-90 Mem No: 1
Location: Huddersfield, WeYo.
Contact:

Re: Smoother without the lambda probe....

Post by Simon Baxter »

We have had lots of problems with universal type lambda sensors.
We use Beru, but Bosch are also good (if you discount that you can wrap the lead 3 times around the van!)
'86 VW T3 syncro panel
'89 VW T3 Westy Atlantic
'81 Porsche 924
SJ Baxter LTD/Brickwerks

Locked