1997 850 - intermittent starting issue

[asdrewq]

Hi All,

I've recently taken on ownership of a family members 1997 850 2.5 automatic estate that they've had for 20+ years.
It's a UK market car. I really enjoy driving it but it's covered 140k miles now & is fair to say it's not in the best condition.

I have a couple of issues:
- Intermittent starting issue - sometimes when starting, the engine catches & starts, but almost immediately dies again. It can take a few goes trying to stumble into life before it starts up & runs completely fine. It's not a battery issue - the cranking is strong.
The car does have a slightly dodgy ignition key switch in that you have to back the key off slightly once the engine is running, or various electrical things don't work (speedo, indicators, seatbelt warning flashers) - I have a replacement switch on order but it feels like the starting issue might be separate?

Does anyone have any ideas how I should go about diagnosing this/common causes?

The Green Lambda light is also on on the dashboard - I think this is the equivalent of an engine management light (although correct me if i'm wrong).
I tried using my generic OBD2 bluetooth reader in the socket in front of the gear lever but cannot get it to connect at all. Does anyone know if there is a specific tool/code reader that works with this age of OBD?

Thanks for any help - I'm completely new to Volvo's (I'm used to working on 1990s Japanese cars) and don't even have an owners manual with the car so am finding everything quite difficult to work out!

[Martin Cox]

As you've already discovered, these cars are not fullly OBD2 compliant and most code readers won't return anything useful.

However the 850OBD2 app for Android phone with an ELM 327 Bluetooth Dongle should work. it's also inexpensive. Searching this forum for 850OBD2 should throw up some useful information.

Replacing the electrical part of the ignition switch should sort out most of the electrical issues you mention but you arre most probably correct about the starting issue being something else.

There is an antenna coil around the ignition switch that communicates with a chip in the key and is part of the immobiliser circuitry. If the ECU doesn't see the correct signal from the antenna, the engine will start but cut out almost immediately.

I'd start by checking the connection to the antenna coil and maybe consider replacing it. This is something of a stock fault and is a common cause of the symptoms you describe.

Hope this is of some help.

Martin.

[Baffler]

Hello and welcome!

In addition to Martin's excellent advice remove and check the condition of the distributor cap and rotor arm. If fouled can cause poor starting and running issues.

Other usual suspects are a blocked fuel filter, fuel pump relay, camshaft position sensor, crankshaft position sensor, engine coolant temp sensor but don't throw any parts at it until you have checked over and serviced all the hardware.

Ignigtion switch is a good place to start and once you have obtained the correct diagnostic tool it'll be interesting to see what fault codes are stored.

140k is only just run in

[Luxobarge]

That's quite low mileage!

As per Martin's post, the ignition switch issue you describe is quite common on these, replacing the electrical part of the ignition switch is quite easy (must be, as I've done it) and will cure that problem.

The starting issue is classic symptoms of bad immobiliser antenna connections, (another common fault on these) - take the steering cowl off (you'll have to do that to replace the ignition switch anyway) and clean the contacts on the antenna ring plug very thoroughly (ideally with proper contact cleaner) and that will probably sort the problem. If not, then replace the ring, it's not expensive. Try cleaning it up first though, this usually works.

As above re. the engine management light, ordinary OBDII code readers won't work, so find/buy/make one that does, and post back here with the codes you get. Actually, when you get a reader that works, note down the codes, then clear them and see what comes back - you never know, it might be a historical code and might be fine now, but if a code comes back you know for sure that it's a current fault and we'll help you find it.

Reading the codes is important, otherwise you're just going to end up throwing parts at it, which is expensive and time consuming, and there's a chance you'll introduce another fault and make life even more complicated.

Have a good read through this forum, there's lots of really good advice, especially on preventative maintenance such as PCV system replacement, vacuum line replacement and cam belt replacement etc.

All the best

[El Padrino]

Hi asdrewq,

I bought this ODBII reader recently and it worked on my car (a 98 V70R). Should work on your 97 850 too as it states it works on cars built from 1996 -
https://www.ebay.co.uk/itm/175354423...3Avlp_homepage

I downloaded the Torque Pro app and it did connect to the car's ECU via the Bluetooth on my Android phone. Hope this helps.

PS: 140K is nothing. Mine has just clicked over 219K and still going strong.

[asdrewq]

Thanks all, really useful information!

Just checking the OBD2 reader I have - it's a generic Chinese one which is labeled ELM327. It's a blue transparent cube-like thing that I think cost about £5 10 years ago so is probably just knackered.

I just remembered I also have a more expensive reader I had to buy to read codes on a Japanese Subaru - an OBDLink LX, so will give that a go too with the various apps before purchasing a new one.

Have to say, despite the niggles I really like the 850 and am glad to have stumbled into it!
Even though I guess the 2.5 non turbo automatic isn't the most desirable model, it wafts about very nicely & is really relaxing to drive, has fairly decent turn of speed, handling is pretty good IMO, the 5 cylinder makes a nice muted noise and all the glass area gives similar vibes to an old Range Rover. The AC is nice and cold too

[4x4]

Not all ELM27 dongles are equal and not all will work on 850 cars

[Bob Meadows]

Worth checking that the gear selector contacts are clean:~
A search will give full details- but a quick answer is to move the lever selector through the working cycle to clean the inner brass contacts.
Bob.

[Luxobarge]

Originally Posted by Bob Meadows

Worth checking that the gear selector contacts are clean:~
A search will give full details- but a quick answer is to move the lever selector through the working cycle to clean the inner brass contacts.
Bob.

The OP's car is cranking, firing and then dying. A dodgy PNP switch would mean that it wouldn't even crank so I doubt it's this. Cheers

[DaveNP]

I'd have to go with the majority on this one
The phrase 'engine catches & starts, but almost immediately dies again' made me immediately think of the immobiliser antenna ring, I had it on mine and it is a quite distinctive non start, the antenna ring is in a plastic case which fits around the keyhole on the steering column and includes the light which comes on around the keyhole when the car is unlocked but the ignition isn't on. As a starting point it can sometimes be fixed simply by unplugging and replugging the ring a few times to clean up the contacts in the plug.
The dodgy ignition switch is a different but known problem which I've not had to do but I believe is cured by replacing the electrical switch part on the back of the ignition lock.
Lambda light as I recall does come on for a few minutes when the car is started as a 'service due' light, but if it stays on then you're into the world of diagnostics which as others have said a 97 850 may have an OBDII socket but it isn't necessarily fully compliant and may need other ways to read it.