'96 NA Volvo 850 Intermittent Stalling Problem

[valvster]

Cheers from sunny Sth Australia....
Having trouble pinning this one down, happens about once a week over the last 6 weeks always when wife is out in the car but I got caught out yesterday....car starts and runs normally in hot or cold weather but pull up at a traffic light and revs slows right down.
Wife knows to put it in neutral, turn off aircon if it's on, and keep the revs up till lights change and she continues her journey and the problem usually doesn't occur again that day and maybe not for another week.
Yesterday after driving stop start through the city and a good blast up the hills freeway I stopped OK a couple of times at lights in a small town then at the 3rd stop the revs dwindled and engine stalled. Managed to start it OK and keep it running but as soon as I put it in drive it stalled and was difficult to start, eventually limped around the corner into a park.
I figured a fuel pump relay and (thanks to Ozark Lee's excellent write-up) swapped out the reconditioned spare I carry with me and we are on our way again with no more problems on a 120 mile round trip ending up back in the city in stop start traffic.
Today after driving for 20 mins problem has occurred again but car did not stall and she has continued her journey OK.
I'm thinking fuel pump but at 600 Aussie dollars I want to be certain.
The CEL is not on and I don't have access to a code reader.

cheers....Valvster

[Volgrrr]

Cheers from sunny Sth Australia....
I'm thinking fuel pump but at 600 Aussie dollars I want to be certain.

cheers....Valvster

Firstly, why don't you check what pressure the fuel pump is putting out - it should be around 40 psi read at the shraeder valve attached to the end of the fuel rail.

Secondly, you should be able to pick up a fuel pump much cheaper than than $600 - try Ebay, get a quote from other Volvo parts specialists in other states of Australia (they've probably never heard of Volvo in S.A), look at importing one in from the US. (FCP Groton, IPDUSA etc.)

Best of luck from sunnier Victoria.

[valvster]

Cheers from sunny Sth Australia....
I'm thinking fuel pump but at 600 Aussie dollars I want to be certain.

cheers....Valvster

Firstly, why don't you check what pressure the fuel pump is putting out - it should be around 40 psi read at the shraeder valve attached to the end of the fuel rail.

Secondly, you should be able to pick up a fuel pump much cheaper than than $600 - try Ebay, get a quote from other Volvo parts specialists in other states of Australia (they've probably never heard of Volvo in S.A), look at importing one in from the US. (FCP Groton, IPDUSA etc.)

Best of luck from sunnier Victoria.

Thanks for your input Volgrrr....
I figure the psi is OK since it drove faultless through the hills yesterday and when it goes faulty It's only for a minute or 2 then everything is OK, it's hard to get the fault to stick. The $600 was a quick quote from my local indy Volvo repairer and included fitting of a non-genuine pump which they source from a supplier in Victoria.

Ballarat/ Ararat....the coldest place on earth
Go the Crows ...Valvster

[valvster]

After further research it seems that fuel pumps either go or don't go. Quizzed the wife a bit more and it seems the revs slow right down when she comes to a stop, she bangs it into park and revs it up till the lights change, wacks it into drive and drives off normally and then there are no more probs for maybe a week.
I have cleaned throttle butterfly with petrol rag(was not real dirty), checked for cracked vacuum hoses, IAC seems to work OK when I turn aircon off and on half a dozen times....the car starts and idles beautifully and is maintained by indy Volvo specialists but they really want to see it when the fault is present.
Fuel filter is due for change at next service.
Thoughts anyone?

cheers...Valvster

[icelandic]

I had this problem a while ago on my 95 NA. Tracked the problem to the MAF connector. Try this: take the maf connector off, see if its clean and put it back in place. See that it fits snuggly. I noticed that my problem started sometime after a MAF replacement, and on the new one the connector does not fit as snuggly as on the original one. It appears that as the engine vibrates and moves back and forth the connection is disturbed.

Icelandic

[valvster]

Thanks Icelandic....1:10 am as I am typing this reply so I will check connector in the morning...I did notice yesterday the top engine steady mounting is cracked so there is excessive movement when the car is revved which would also move the MAF sensor connection.
cheers ....valvster

[valvster]

Can some-one recommend a good aftermarket fuel pump....the Walbro pump is available in OZ but I read they have a reputation for whining.
Does stuff from Professional Parts Sweden(Proparts) have a good reputation and where can I get their parts from in USA?
cheers ....Valvster

[jblackburn]

Part of me doubts it's the fuel pump...they usually work one day, and then don't work and never work again. If the pressure was low, you'd have problems accelerating and hesitating all over the place.

When you stop and it tries to stall out, what happens if you just put it in neutral? Does it still try to die if you don't hold the revs up? That could very well be a mass airflow sensor - try cleaning it, and then ziptie the connector down tightly.

If it dies as soon as you put it into drive/reverse and while slowing down, I wonder if you're having the same problem as somebody else with a torque converter lockup solenoid: https://www.matthewsvolvosite.com/forums ... =1&t=25064

[biggytwo]

That would be my story..intermittent car stalling and car shutting off when slowing down at times but when immediately put in neutral or park the car idles fine. Try to put into gear and it sometimes dies.

The car is at the local shop now and I will not know anything until Thursday at the earliest. If the solenoid is confirmed or if another possible problem is found I will post back.

Steve