850 will start, but won't keep running

My '96 850 GLT will start and run for about 10 to 20 seconds, then
stumble and die. I wait a few seconds, restart it and the same thing
happens. This just started yesterday, with no forewarning symptoms.

Any ideas?

 

need a new fuel filter, need a new air filter?

 

If you press the gas some does it stay running?
If yes, clean the throttle plate.
Look at the hose from the air filter box to throttle plate and
see if it has come loose, split or broken in two.
BD

 

unplug the air mass meter, start the car and see if it will idle, if so the AMM
is probably bad.

 

Where is the air mass meter located?

 

I checked and the hose from the air filter box to the throttle plate is
intact. And, pressing the gas actually makes it quit sooner... as if it's
run out of gas.

 

Here is a very useful link to research and find information regarding a
wide range of Volvo issues and self-help instruction. About 3/4 of the way
down the page you'll find "Electronic engine systems components, 850/70
Series" You'll find a diagram identifying the location of the Air Mass
Meter: http://www.volvoclub.org.uk/information-850-70.htm

Many of the indepth instructions and articles are in .pdf format so you
may need to download a viewer from the Adobe Acrobat website.

 

Have a good waggle of the igntion key back and forth slightly after you've
started the engine. These often wear and go faulty and cut power to the fuel
pump- especially if you have a big weight of other keys hanging on the fob.

Otherwise fuel pump relays often die on the 850 too.

Tim..

 

Fellow listers:

Here's an update on the original post:

I sent the car to a mechanic, who sent it to another mechanic with a OBD
reader, who said that two codes came back:

1) Bad engine temp sensor
2) Bad EFI computer

He said that it's more likely to be a bad EFI computer, which would also
give a false bad reading on the temperature sensor.

This didn't seem like the best of news and I asked him the cost of
another EFI computer. His reply was that he tried the local junkyards
(He KNEW I'd turn down the dealer option instantly), but could not find
one. He estimated that it would cost ~200.00 from a salvage yard
somewhere.

However, upon reflection, I wonder if this is the case. I know the car
was running just fine the day before. Next day, just after I started it
and went down the road 1/8th of a mile, when the engine died.

First off, is there a separate fuel injection computer? Secondly, what
is the cost of such a device? And thirdly, is this a likely scenario?
Fourth, where might I find an "EFI computer" reasonably priced, if
that's what I need?

The car is a '96 850 GLT, non-turbo 20 valve, 5 cylinder engine.

Thanks all...

 

could be the air mass meter.

 

You need a real mechanic who knows what they are doing.

Mechanic #1 who doesn't even have a code reader is clearly not a qualified
mechanic in the modern world.

Mechanic #2 who just reads out some codes does not sound much better.

You need someone who is fully familiar with Bosch engine controls and better
yet with Volvos. This either means a Volvo dealer (if you know a good one),
a good independent Volvo specialist, and/or a Bosch certified independent
specialist.

This is not a problem to fix by internet remote control or by unqualified
technicians.

John