Stalling

[Angie]

I wonder if anyone can offer any ideas about this.

Our 1992 240 Torslanda has been intermittently stalling while driving. It doesn't seem to bear any relationship to road conditions, going up steep hills, for example. In fact it's happened more frequently when going fairly slowly and under light power. After a little while, sometimes no more than half a minute, it starts easily and then runs perfectly - until the next time! It might go for days without it happening again, or could do it twice in quite a short journey. Some time ago it did give a little trouble starting up when warm, but again, after a little while all would be fine. I read somewhere on here that the petrol pump fuse might cause a similar problem and taking the advice of a knowledgable friend changed the fuse and cleaned the fuse carrier. I did notice siome darkening of the fuse carrier at one end, whereas all the other ones were clean and shiny, so hoped that changing the fuse might have done the trick - but no such luck! The local garage suggested that the petrol pump might be faulty and using too much current, but before going to the expense of a new pump, and possibly finding that it wasn't the problem after all, I thought it worth enquiring of all you helpful people here.

Sorry to have written so much but I hope the information might help the diagnosis.

[callumk5]

I had a similar problem with my '92 SE which has the same engine and injection system. Sometimes when driving the engine would just shut down as though someone had switched the ignition off and eventually it wouldn't start at all. My problem was solved by replacing the fuel pump relay which seems to be a common fault on cars of that age. There was a really good post a few weeks back explaining where it is and how to change it;

http://www.volvoforums.org.uk/showthread.php?t=118932&highlight=fuel+pump+relay

Might be a good place to start. I found a new relay on ebay for a few pounds. Hope this helps.

[Angie]

Goodness, I didn't expect a reply so quickly! Thank you, it might be sensible to look at that before risking a big bill for a pump.

[Clifford Pope]

Two other possible culprits are the Crank Position Sensor (On the back of the engine block on top of the bell housing) and the Ignition Amplifier Module (on the left hand inner wing just in front of the battery).

The CPS or more specifically the wires go brittle with age and the insulation disintegrates. If it is still the original it will be on borrowed time.

The IAM corrodes at the heat sink face, distorting the module and causing intermittant faults, non starting, or cutting out.


Apart from fuses, fuses, fuses, and fuses, my cutting out faults have on two occasions with different cars with this system both been sudden failures of the IAM.

[callumk5]

I'd forgotten about the crank position sensor- mine went a couple of years back because of dodgy wiring. That caused a few non-starts. The Lambda light on the dash didn't come on with the ignition warning lights when it happened.

[Angie]

It's all so complicated isn't it? But thank you for taking an interest.

It cut out twice this afternoon, within the space of a couple of miles, each time started after a minute or so, and each time when the engine wasn't working hard. In fact the second time it was downhill! I fiddled with fuse number six, just in case, but it didn't help. What I also noticed was the very fast idling, about 1,500 rpm. The Lambda light has been on for most of the time we've had the car, last August, despite attempts to find the reason. The idling has caused problems in the past too but seemed to improve after they changed the temperature sensor - which I think is also at the back of the engine. It races away sometimes still, but usually calms down after a while. Today when I came home, after a trouble-free main road drive, the idling was normal, and perfectly smooth. Does all that point to anything in particular.

I knew we should have kept the Moggie Traveller. When the petrol pump failed a good thwack with a stiletto generally did the trick!

[tannachyallen]

............The Lambda light has been on for most of the time we've had the car, last August, despite attempts to find the reason.................

If the lambda light is on you must have fault codes logged. Have you read them for a diagnosis? If your'e not sure how, wooble has put up a good 'how to' article here: http://www.volvoforums.org.uk/showthread.php?t=122474

cheers,

Dave A.

[Angie]

It always gives the same results, mixture too rich or too weak at cruising and at idling. If it's reset the engine usually runs roughly for a few miles then settles down until the light comes back on a few days later. The car runs well and seems to have plenty of power.

It never fails to start from cold, by the way, and usually starts well when warm too, just these unpredictable times when it goes doolally.

[tannachyallen]

It always gives the same results, mixture too rich or too weak at cruising and at idling. If it's reset the engine usually runs roughly for a few miles then settles down until the light comes back on a few days later.

Until you sort the problem the codes will keep logging. Just resetting it won't help.

The codes and symptoms are pointers to the problem area. Codes are only guides.

I had similar codes and some of the problems you mention which ultimatley were cured with a new (secondhand) MAF sensor.

Dave A.

[Angie]

Just a short follow-up. The mechanic decided that the problem was the fuel pump, but a new one didn't cure the fault He then tested the relay, which was definitely faulty, so having had a new one the car seems ok. We've not used it very much since, but tried it under all sorts of conditions over a fifteen mile trip and all seems well so far. I wish he'd started with the relay, it would have been a lot cheaper, but he seemed to think that the fault in it was caused by a defective pump. We shall never know!!

Thank you for the various bits of advice.

[jetronic63]

I knew we should have kept the Moggie Traveller. When the petrol pump failed a good thwack with a stiletto generally did the trick!

That made me laugh - thanks for that :o) - hope yours is fixed now, the relays are usually the culprits and its a shame your mechanic didnt start with this as its the one of the simpler and cheaper routes to sorting the problem. Anyway, fingers crossed your sorted now.