94 850 Turbo starts fine but dies when driving

arlo1870 · Post by **arlo1870** » 08 Mar 2015, 03:53

Love my 94 850 Turbo Wagon but it does have it little issues like fan cutting out on heat/AC after a couple of minutes, and rear door not always locking. Then last week it starts dying on me, I haven't had any real mechanical problems with it since purchased (6/2010). Finally I get it home and park it, luckily I was about 1/4 mile from home when this started. Each time it dies I have to set a few minutes before it will restart, then when I try accelerating or slowing down it dies again. The next day starts fine but dies while I am pulling into my alley and backing up to change direction of travel. Then I get a couple hundred ft. and dies again. At this point turned around get home and park it. I would greatly appreciate any useful input.

Post by **jreed** » 08 Mar 2015, 07:14

There are many possible causes of stalling. One of the most common is a failing fuel pump relay, but this is just a guess. To check it, I would recommend following the instructions in this classic fuel pump relay thread:
https://www.matthewsvolvosite.com/forums ... php?t=9681

There is a good general list of possibilities for the causes of stalling here. It might give some ideas for things to check:
https://www.matthewsvolvosite.com/forums ... 5917#65917

Post by **jblackburn** » 08 Mar 2015, 10:51

Unplug the mass airflow sensor and see if it will stay running on its own.

Post by **rspi** » 08 Mar 2015, 13:05

Any codes or CEL?

Post by **erikv11** » 08 Mar 2015, 13:43

Mass air flow (MAF) sensor is the first thing to check. Unplug it before you start up the car, then drive it around. If it no longer dies, that was your problem. Post up your results people can advise you on getting a replacement.

If it is not the MAF then I would probably look next at the fuel pump relay.

arlo1870 · Post by **arlo1870** » 12 Mar 2015, 11:10

I unplugged MAS once I found where it was located and it made no difference. Tried to drive and again keep dying when I when to stop or slow down to turn.
I purchased a OBDII & CAN SCAN TOOL. Then found it is missing the cable to connect to PC.
I ran a scan following directions I saw on a Robert DYI video.
Codes were POOO! Fuel volume circuit open.
PO331 Knock sensor-2 circuit range performance
PO326 Knock sensor-1 Blank
Also under DTC Guide Open or short in Park Neutral position switch circuit Poor Park
Neutral position switch circuit connection, Misadjusted park, Faulty Park neutral switch position.
Thanks for your original suggestions. I am going to go try pulling Fuel relay and running the wire between the two slots to test as suggested on one of the videos I watched on line.
Would appreciate any additional recommendations.