1994 850 will start but only run for a second, then dies

offbeat · Post by **offbeat** » 03 Mar 2008, 14:21

Like many others on this forum I had the dreaded upside-down 'Y' symbol on the dash - apparently signifying a Lambda Probe problem - then about two weeks after the car engine dies while I'm driving along, and can only be cajoled into life sporadically. I manage to get the engine running for a few minutes, enough to get the car home, and now no matter how well charged the battery is, the engine will fire up first turn of the key, rev up to about 1500rpm and then abruptly stop.
One curious thing - whenever the ignition is on I hear a loud low-frequency clicking, which sounds like it could be the fuel pump - and I wonder if all these problems might have been caused by my running the car very low on fuel recently?

All inputs welcome! My beloved 850 is in dry dock as we speak, and my wife and I are stranded in monsoonal downpours here in Far North Queensland!

Cheers
Steve Rothwell
[email protected]

Post by **MadeInJapan** » 03 Mar 2008, 14:42

Read your codes and let us know what they are. They are invaluable in telling us which way to look.

offbeat · Post by **offbeat** » 03 Mar 2008, 14:48

I'm sorry to say I am a complete newbie to reading codes .... I'll go hunt through the forum to find out how to do this?

Post by **MadeInJapan** » 03 Mar 2008, 14:52

http://volvospeed.com/Repair/a2.html

Then we also have our very own trouble code library in the repair database section:
https://www.matthewsvolvosite.com/chat/p ... hp?t=10758

Btw, welcome to MVS!
Regards,
MIJ

offbeat · Post by **offbeat** » 03 Mar 2008, 15:17

Thanks very much MIJ!
I must say, after asking my Dad to look at the ailing 850 and given he was a mechanic all his life but lamented "Ooooh these modern cars, you can't do anything with them these days; in my day with a gob of spit and piece of wire .....etc" - so for me it is most encouraging to come across such a fund of knowledge as this forum!

I got the code of 433 - seems to indicate "Rear Knock Sensor Missing or Faulty" ..... any tips on how to find/replace/inspect this sensor?

Cheers

Steve

offbeat · Post by **offbeat** » 03 Mar 2008, 15:26

Thing is, I'm just trying to nut this out now .... the Lambda Probe / (Oxygen sensor?) warning light came on before the car came to a sudden stop. Hmmm, I'm not sure which of the two faults - bad signal from the Lambda Probe or 'Rear Knock Sensor Missing or Faulty' would actually conspire to stop the car. I will say the battery is on its way out and does need replacing anyway.

Anyone have any tips about doing something about the Lambda Probe light? Is this something one can buy as a replacement probe and plug it back in to the system? Or can the probe be cleaned or reconditioned?

Any input welcome.

Cheers
Steve

Post by **Ozark Lee** » 03 Mar 2008, 15:56

The lambda light on European and Canadian cars is the same thing as the check engine light. It doesn't really refer specifically to the Lambda Probe (Oxygen Sensor) but rather to the entire engine management system. The code you pulled doesn't indicate a problem with the O2 sensor. At the same time it really doesn't indicate a cause for your problem.

A low battery charge will create many problems so that is where I would start since, from your description, it sounds like you will need a new one anyway. Replace the battery and reset the code. Be sure that you have your radio code before removing the battery.

...Lee

Post by **MadeInJapan** » 03 Mar 2008, 17:02

I concur with Lee, however you never mentioned if your car is a turbo or not. On turbo cars it's important to use higher octane gas. If after your battery swap (make sure you have your radio code as you'll need this once the power to it is disconnected) you still get the knock sensor code try using a higher octane gas and see if the code can be reset and not come back.
Good luck and keep us posted.

offbeat · Post by **offbeat** » 03 Mar 2008, 17:11

My 850 is naturally-aspirated. Good points taken about fitting a new battery first, then I will try higher-octane fuel anyway. The motor burns oil when initially fired up - prob leaky valve guides - I wonder if this oil smoke could cause emission control sirens to go off, and disable the car?

offbeat · Post by **offbeat** » 03 Mar 2008, 22:04

I fitted a new battery of a higher rating, and the 850 started up first turn. It ran fine for about one minute, then died. It will not be coaxed back into life. Sometimes it will just fire, and die again.

I checked the fault codes and in A2 it came back 1 1 1 - so effectively, clear.

I took the liberty of opening the fuel injection rail Schrader valve with the ignition on, and all I got as a very small dribble of fuel. Could this possibly indicate the fuel delivery is at fault, either through a failed fuel pump or a clogged filter?

I am hearing a low-frequency clicking/humming around the dash area ... which from what is commonly said on this forum would seem to point to the fuel pump relay. That will be my next area of investigation.