1986 740 Turbo Dies at low idle

[Berkeley]

I just purchased my first Volvo a week ago as a spare vehicle. I drove about
50 miles today and pulled over on the side of the road (highway) to snap a
photo (and left the car running). I returned to the car and took off back on
the highway, the car reved up to about 3200 rpm then shifted, after shifting
it felt like it lost power and I was having trouble maintaining 55 mph
without it down shifting on flat surface. So I was almost to my family
members house in Southern Oregon, when I pulled off the highway to a dirt
road I lost all power and the car died. I started the car and it felt as if
it was missing, and had to use the accellerator to keep the car going. Died
3 times in 1/20th of a mile to the house at which now I am stranded. We
thought maybe it was not getting gas (fuel filter) but when I pulled the dip
stick the oil smelled of fuel which makes me think it may be flooded? It is
injected though. Could this be the mass air sensor? There are so many
vaccuum lines because it is an Intercooled Turbo I would not know where to
begin? Could this be the fuel filter? How major could this be? I can keep
the car running with the throtle, but it seems to run rough at certain rpm's,
and will die if not. Also I was able to keep the car running at idle for a
few minutes where the idle would drop to almost die, then resume normal idle?
I do not know much about Volvos, but I would sure like my experiance with my
first volvo to be a good one, but I am getting off to a rough start. Any
suggestions will be helpful, and I am open to anything, as I am stranded 60
miles from home with my pregnant wife.

Berkeley

 

[James Sweet]

I just purchased my first Volvo a week ago as a spare vehicle. I drove about
50 miles today and pulled over on the side of the road (highway) to snap a
photo (and left the car running). I returned to the car and took off back on
the highway, the car reved up to about 3200 rpm then shifted, after shifting
it felt like it lost power and I was having trouble maintaining 55 mph
without it down shifting on flat surface. So I was almost to my family
members house in Southern Oregon, when I pulled off the highway to a dirt
road I lost all power and the car died. I started the car and it felt as if
it was missing, and had to use the accellerator to keep the car going. Died
3 times in 1/20th of a mile to the house at which now I am stranded. We
thought maybe it was not getting gas (fuel filter) but when I pulled the dip
stick the oil smelled of fuel which makes me think it may be flooded? It is
injected though. Could this be the mass air sensor? There are so many
vaccuum lines because it is an Intercooled Turbo I would not know where to
begin? Could this be the fuel filter? How major could this be? I can keep
the car running with the throtle, but it seems to run rough at certain rpm's,
and will die if not. Also I was able to keep the car running at idle for a
few minutes where the idle would drop to almost die, then resume normal idle?
I do not know much about Volvos, but I would sure like my experiance with my
first volvo to be a good one, but I am getting off to a rough start. Any
suggestions will be helpful, and I am open to anything, as I am stranded 60
miles from home with my pregnant wife.

Berkeley

First thing to check are the large hoses between the turbo, intercooler,
and intake manifold. Sometimes they develop tears or pop off. It could
be the air mass meter, try unplugging it and see if it idles any better.
You'll also want to check the engine wiring harness, this car is right
smack in the middle of the biodegradable wiring era and if the harness
is original it is probably shot. Look at the exposed wires where they
plug into things like the oil pressure switch, coolant temp sensor, etc,
if the insulation is cracking and crumbling off the wires, replace or
rebuild the harness. My 740 was behaving similarly, intermittent loss of
power and then one day it just died and wouldn't start. When I cut open
the harness section under the intake manifold, it was a bundle of mostly
bare wires in a pile of insulation dust, amazing the car ran as long as
it did. Take care of a few common issues that crop up though and you've
got yourself a pretty solid car. The basic mechanicals of these things
will run pretty much forever.

 

[zoltamatron]

Sounds ignition related......i'd replace the plugs, wires, cap and
rotor. If you're stranded and just want a quick fix to get home, then
just do the wires.....that is probably where the failure is. If you
want a really quick and dirty fix, then just wrap electrical tape
around the spark plug boots as the wires are probably shorting there.
That may at least get you and the car back home.

 

[Berkeley via CarKB.com]

Sounds ignition related......i'd replace the plugs, wires, cap and
rotor.

The car jsut had a full tune up about 1 month ago, cap, rotor, wires, plugs
all done by Volvo. I am thinking it has a fuel issue. I am going to check
vaccuum lines and the turbo lines. Started the car today, and it will run
for about 5 seconds then die, started again revved the engine to 2 k rpm,
then just died as well. I seem to think it isnt getting fuel, or too much
fuel. after starting it 4-5 times it smeeled very badly of gasoline and a
big poof of smoke shot out the exhaust on our last try. (wasn't blue smoke,
just like a flooded engine smoke) Does anyone know how I might be abl to
tell if the car is flooding? What could cause flooding in an injection?
Thanks so much for everyones help so far!

 

[James Sweet]

The car jsut had a full tune up about 1 month ago, cap, rotor, wires, plugs
all done by Volvo. I am thinking it has a fuel issue. I am going to check
vaccuum lines and the turbo lines. Started the car today, and it will run
for about 5 seconds then die, started again revved the engine to 2 k rpm,
then just died as well. I seem to think it isnt getting fuel, or too much
fuel. after starting it 4-5 times it smeeled very badly of gasoline and a
big poof of smoke shot out the exhaust on our last try. (wasn't blue smoke,
just like a flooded engine smoke) Does anyone know how I might be abl to
tell if the car is flooding? What could cause flooding in an injection?
Thanks so much for everyones help so far!

So far it sounds exactly like a bad air mass meter. Did you try
unplugging it to see if it runs better?

 

[Michael Pardee]

First thing to check are the large hoses between the turbo, intercooler,
and intake manifold.

Also closely check the short hose between the Idle Air Control Valve (under
the throttle body) and the intake manifold. If it cracks it will cause
exactly those symptoms - anyway, that's what happened on our '85. If it is
cracked it can be patched with electrical tape for now, but use lots of
layers because it has to hold against the turbo boost.

Mike