Official Engine Stalling Thread

[bills '94 850]

[edit] If you've never read this thread, take the time right now to read the whole thing. If you post a question to this thread that has been answered in this thread, I will remove your post. Thanks -- Matt [/edit]

[edit] the title of this thread was 850 engine cut out- Need Matthew's Support. Changed on 29/4/2005. Thanks -- Matt [/edit]

there are alot of 850's that seem to have this cut out problem. I have the same in mine and haven't found the cause. Same tech tip-have to have the car in motion and wait till it stops before being able to diagnose it. I agree it is really dangerous.
Has anyone found the cause definitely????
Can Matthew the administrator collect from us members who have all the similar probs and take it to the Volvo Engineers? That would be good wouldn't it. Is there a portable instrument gauge that reveals the problem codes while driving? instead of sitting in a workshop?

[matthew1]

I will "sticky" this post for a few weeks, and if it gets many "me too's" I'll make a page -- something more permanent.

As far as the stalling problem, does anyone have insight into if there is a usual suspect to it? I've read that a new fuel pump has fixed this.

As far as codes go, most OBDII-compliant vehicles will transmit data in real time via the port under the ash tray. The problem for you is you need a 1996 or newer Volvo to have OBDII. I don't know of any way to get data in real time from pre-OBDII cars.

[lxt]

Nothing much to say, just want to add a "me too" to the thread.

To help make a collective conclusion on this, I think we should define the symptoms (if it's different it might be entirely somethin else), and also how many times/how often it happened, the cause/fix if any. I'll suggest the definition as: "car stalls while driving. Restart and drive ok" (until the next stall).

Now, for me:
How many times: 1
Fix/cause: none
Codes/other special circumstances: none

[tina]

HAVE you replaced the fuel pump (and/or fuel pump relays)?

I replaced fuel pump last year after my '94 850 stalled out in traffic. (It later started again then stalled etc. limped it to the garage) Yes the fuel pump was the problem.

There could be many causes for stalling including O2 sensors etc. Surely yuor mechanic can diagnose whether fuel is getting interrupted to the engine after a stall? Have it towed to the garage and have them look at it right after a stall...

[dosbricks]

Tina may have hit on a diagnostic point here. If the car stalls and you shut the ignition off and don't try to restart it, but instead loosen the connection at the fuel rail.... if no gas spews out, then likely fuel pump problem.

Normally the fuel system is pressured all the time whether the car is running or not.

By the way, this would mean taking care not to get any gas on the hot exhaust.

Just throwing in my 2 cents.

[8fiddy]

FYI my 94 has OBDII, i haven't used it yet but I hear Volvo got anxious and started putting it in the early cars, actually mine might have OBDI and II. It says OBDII Certified on the Emissions sticker on the pssngr strut tower. I also heard that the early models with OBDII that it was only for engine diagnotics.

[bills '94 850]

Looking at Tina's comment. I have changed the fuel pump relay and still no fix. I will now try changing the fuel pump, and do a check on the fuel rail to see if there is pressure. I hope there is, I'll probably splatter some on the exhaust to give a final fix to the car. It's so maddening and frustrating.
I've heard there are 2 fuel pumps. Is this so?

[jaljamma]

The butterfly in the throttle valve is pre-set at the factory to a very small gap, and with time and mileage there is a build up of oil and carbon which reduces the gap enough to send wrong information to the engine management system. The butterfly needs simply to be cleaned and the gap checked. Volvo dealerships are aware of this.

I found this information while surfing a UK Volvo site

http://www.volvoclub.org.uk/850reg.htm

Good luck.

[RKC of Kenginston]

This is a me-too reply.

My 93 860 5 speed manual (just over 100K mile) had this problem since last July. It would stall when pulling to a stop light but I could away restart after waiting for more than 30 seconds. Replacing the fuel pump relay and idling sensor did not help. The mechanics at my local dealership drove the car for two weeks and it did not happen to him. The service manager thinks that I am imaging the whole thing up. Until two weeks ago, the engine did not fail during freeway driving. The first time it occur while driving at 65 mph was quit unnerving. But the interesting thing was that the engine did not completely die. It just lost power. By keeping the accelerator down, the engine recovered after about 30 sec.

I suspect this to be a electrical problem as the car has a lot of phantom warning signs (i.e. imtermittent low oil light flashing and failed breaklight indicator on when the bulb is good etc). It tends to occur when the A/C and temperature auto are both on and also after the car has been idling for a while.

[dosbricks]

http://www.matthewsvolvosite.com/chat/p ... highlight=

Something else to look into if fuel pump is not the culprit.