Unfixable Stalling 850 from H**L: Fixed!

I bought a beautiful, low mileage 1995 850 T-5R for a very good price because it had an
"unfixable" intermittent stalling problem

Here is a report of how it took almost six months to resolve

New Fuel Pump:
I started by putting in a new fuel pump, because it was the most common cause of this set of
symptoms, it had never been replaced before and it was 15 years old.

This car was a little behind in servicing, so I also threw a full tune-up at it.

I drove the car around town, to and from work, errands, and it went about 2 weeks before it
stalled again.

Troubleshooting:
Now I've installed a fuel pressure gauge and duct taped it to the windshield to I can see it while
driving

Volvo factory scan tools shows no stored Diagnostic Trouble Codes (DTC's). This is not unusual
or unexpected because in 1995 on-board diagnostic systems were somewhat crude, early stage
systems.

I installed a new air mass meter, because the unit appeared original. No real reason to think its
bad, but it might be the culprit. No luck, the car stalls again about a week later.

Next, Seriously "Throwing parts at it"
Installed new fuel pressure regulator, front and rear oxygen sensors, engine speed sensor

Test drove around the city, after about 2 weeks the car stalled again.

On the bright side, I've new begun to see a pattern. The stalling has only happened when
a) engine fully warmed up
b) the transmission is in drive, foot off the gas, coasting down a hill

I ordered and installed a new ignition coil. I don't think I've ever seen one fail on an 850, but not
too expensive, and I've got to try something.

After about 2 weeks the car stalls again, same conditions, coasting down a hill, warm engine.

One of my technicians now recalls that one time, years ago, he had experience with a defective,
brand new fuel pump. OK, worth a try, so ordered and installed another brand new fuel pump.

Weeks go by, stalled again, still not fixed.

Now, (sound of hand slapping forehead here) tech recalls that we have not yet changed the
camshaft position sensor, and its still the original unit. This revelation is a bit frustrating, as it is a
much more likely suspect for this sort of problem. So in goes a new unit.

Two more weeks of test driving, stalls again.

Now we discover several pieces of vacuum hose may have small leaks. As this car is
Turbocharged, only special heat resistant vacuum hose will do, and we order if from the Volvo
dealer. Special order part, means they don't sell it often. It arrives, we install as needed.

One week later, car stalls again.

Epiphany:

Another, more senior tech is consulted and suggest the main fuel injection control computer
might be the culprit. No one in the shop has ever seen one of these fail before, and common
wisdom has it that when they do fail, the car just won't run at all. Regardless, we order and
install a fuel injection control computer.

Interestingly, and very encouraging is the fact that the engine seems to start a tiny fraction of a
second faster now !

I test drive the car around the city for 2 more weeks, just looking for places where I can coast
downhill.

Oh, did I mention before that when the engine does stall, it won't start up right away? It will
crank over but not start, just like it ran out of gas. This means that I have to choose my test drive
very, very carefully. Don't want to stall on the Bay Bridge, or Market Street in rush hour, eh?

Two more weeks of test driving and I decided to re-install several of the original parts that were
probably OK from the beginning.

After two more weeks of daily driving and I now feel it really fixed.

Can you imagine just how difficult this would have been to sell this package of repairs to a
paying customer? They would have to have the patients of a Saint and the wallet of Bill Gates!

How about to a new customer who does not yet built up a relationship with the shop? I can
imagine that situation because I've been there, more than once. Intermittent problems are not
unique to any particular make or year or model. But they always pose a unique challenge for the
owner and the repair team.

In Hindsight / "Next time"

Many months have now gone by and the problem is resolved with certainty .

The fuel pump is still the place I'd start. We have seen old fuel pumps fail time and again. Never
a code and usually intermittent.

Changing the fuel control computer is simple (if you don't count the cost of parts). And maybe
some customers would be willing to accept the risks involved with test driving ( and getting
stuck).

New technician ?

Received  an application from a prospective new technician today, who says he has 'tons of experience', and used to work in the aviation industry. 
To hire, or not to hire: What do you think?

Customer quote of the day:

“The $2,500 we paid today to put my car back in top shape is less than the sales tax would have been on a new car”

( husband of happy customer )

A new headlight costs how much ?!!

How much will it cost to replace one headlight on my Volvo?

Well, that depends....

In the best case we install a new “long-life” bulb and we’re done ( <$40 )

However, starting around 2004, some cars came equipped with bi-Xenon, high intensity discharge (HID) lighting systems, and these bulbs are $125 each.

However, Volvo has a service bulletin regarding rapid bulb burnout that introduces a resistor kit, so if you don’t already have one, it may be a good idea ( $150 with 2 new non-Xenon bulbs)

However, we will always check to see if the reflector that surrounds the bulb is not broken. If it’s broken and wobbling then again expect rapid bulb burnout ( and $525 for one new headlight assembly)

And lastly, one or two time a year  we discover the ECM ( electronic control module ) that sends the signal to the headlight has also failed.  If so, then after about an hour of diagnosis, $750 to $1,250 ( per side)

Our suggestion for smart maintenance is : 
    a) replace faulty headlight parts as soon as possible    
    b) always change bulbs in pairs
    b) install the headlight resistor kit where applicable
   

Volvo Free Software Update Available

As some of our customers have already heard, Volvo recently created a program offering lifetime complimentary software upgrades for most 1999 and newer cars ( early model S40, V40 and C70 are excluded ) 


 Why do I need new software? Because software evolves and makes your car more "fault tolerant", for one. As you probably know, there are many small computers in today’s cars. And like most computers, the software might need an update from time to time. Technical advancements move quickly nowadays, so it's difficult to specify exactly what an update in a particular car entails. It may involve things like optimizing the engine management system for increased efficiency, optimizing the climate control for airflow and temperature management or improving automatic transmission gear shifting quality. 


Volvo is continually developing new software and providing updates is a way for us to ensure that your car is operating at its best. Over the last few years, Volvo has taken service to new levels and now, Volvo will offer owners complimentary software updates for their late model Volvos. The program "Service for Life", applies to nearly all Volvo models made over the last 10 years. 


 Volvo’s new Service for Life program is good for any of its covered products, even if the vehicle is in its second and third owner. This should help the resale value of these vehicles if second owners can get the same service as a first owner. 


 In a nutshell, what you need to know is Popular Mechanix can offer this complimentary program, “Volvo Service For Life” for you, in our shop, right now. 


 As always, please schedule an appointment, either by phone or our DemandForce website Thank you for your ongoing business & support!