I've been thinking about this and I'm sure we can get to the bottom of
it.
+++ Hi Tony thanks for all your comments. I'll try and answer them the
best I can (I'm not very technically worded)
Initially the car was having problems in motorway driving. A loss of
power occured at 50 mph where the revs just died and then the car
stalled.
This is a contradiction. I guess you mean just a loss of power and
the
engine died. Was it total a loss or did it start by missing /
stuttering?
I don't understand how the revs died then it stalled. Did you
clutch-in and
ty to rev up the engine?
+++ Was hubby that was driving when this happened so don't know for
sure. But what I understand to have happened is this: car is doing
50mph then started to lose power going down to maybe 30mph and then
the revs just dropped like a stone to 0mph and all the lights on the
dash came on = car stalled. Not sure on this occasion but there has
been hesitation and stuttering as well.
Gradually loss with stuttering can be fuel problems, one of which is
carb
icing which happen in the cold if your warm air thermostat is faulty
or the
warm air feed is missing or damaged.
+++ not cold. Mild summers morning and evening.
Total fuel blockage is very unlikely, there are several filters each
of
which is very difficult to block in one go, presuming the main
consumables
have been changed.
Ignition problems at low revs can be reved out off usually, but can be
difficult to restart if you let it die.
+++ I think this has happened in the past as well (before the carb was
changed) where hubby 'revved hell out of it' and the problem went
away....for that day anyway
Hubby stopped driving it on the motorway and we swapped cars.
I was using it as a local run about - driving 15 - 20 mins to my work
and back and it seemed fine.
Then it started not restarting when warm. Did this on several
occasions and could take up to 1/2 an hour to get her restarted again.
Consistent with carb icing. Did the car run fine after it restarted?
Was
it cold or misty?
+++ no again warm summers day. And no the car was still the same after
restarting.
Car then went in for its MOT and service. After this seemed fine again
for about a month. But recently she has started having problems again.
First off first thing in the morning she would start and then die
immediately then it would take another couple of attempts with choke
fully out to start her. But apart from that OK. Then she stalled going
up a hill at a junction near my work. She then did this three days in
a row at exactly the same place.
Not consistent with carb icing or oil in the distributor, but could
just be
bad carb adjustments /assembly, burnt exhaust valves or just general
old car
syndrome. Not that its not fixable, it just might not be linked to
other
fault.
+++ well we have had a problem with the car hesitating at certain gear
changes (mainly 3rd and 4th) which now seems might be related. Our
mechanic looked at it and said it was carbon buildup on the valves
(forgive me if that is not correct terms?) caused by age he said and
put an engine treatment into it which seemed to make the problem
better but didn't solve it completely.
Then the other night we took her out together. Seemed not too bad at
first but kind of rough idling and then started cutting out again at
speed.
Rough idleing, could be leaky ignition due to old leads / damp / oil
in
distributor.
+++ new leads and oil as just been serviced. Distributor cap changed
about a year ago. Maybe needing new one? Mechanic did say there was a
lot of oil around the engine when he serviced it and wanted to get it
in and steam clean it to find out where it was coming from. Do you
think then it could be oil in distributor cap?
Idleing is controlled by a seperate fuel circuit in the carb, so any
problems here and the car wouldn't run at idle.
+++ car isn't bad at idle...cept when this problem starts to occur.
We were doing maybe 40 - 50mph and the revs would just totally
die (and at this point we could hear a kind of hissing?).
This could be the typical problem of the warping manifold / carb and
subsequent air leakage, but it would not normally stop the car unless
you
refused to rev it (clutch in and pump the accelerator until you get it
running properly), or simply put it in a lower gear.
+++ well the other day when it happened I was going maybe 20 - 25mph
in 3rd or 4th (can't rem) and when I noticed there was no power in the
accelerator I started to pump the acc and change down gears but the
revs just slowly dropped to 0mph as if nothing I was doing was
helping. I suppose it could be warped manifold but I think the new
carb came with an adpation kit that was supposed to seal that up?
Hubby seems to be able to drive the car when she starts this by
keeping the choke out and keeping her in high revs.
Hissing can happen as a result of very bad ignition, when air
pressurised in
the cylinder leaks out through the imperfectly sealed valved, not
having
exploded. It does depend on what you mean by hissing.
+++ I dunno...just seemed to be a faint hissing / noise coming from
the front drivers side of the car when it was losing power?
Once or
twice they came back up again and the car bucked. Other times she
would stall and it would take a few attempts to get her started again.
Now the car has had a fair amount of maintenance done on her in the
last year. New distributor and rotor arm, new leads, sparks etc
(twice) and a completely new carb (when we were advised by a Volvo
dealer that was what was causing the problem). As you can imagine we
are getting somewhat frustrated with it all as it seems no-one knows
what is up with her.
From what I read on here I wonder if it is a dying fuel pump? Or a
blockage in the fuel line? Or does anyone have any other ideas?
I doubt the fuel pump would fail in this way, or even a blockage.
Pieter
mentions a possible blockage in the tank breather causing a vacuum to
form
in the tank. I used to get this in my 340 1.4 (you'd hear a sucking
sound
when you pulled of the filler cap), but it never stopped the engine.
Also I
think the 1.7 breather is better designed.
+++ yeah this has never happened to us.
The car is booked into the garage next week but just wanted to get
some more volvo related opinion form this group as I don't have a
great deal of faith in our mechanic getting to the source of the
problem. Any help or advice very gratefully recieived.
DD
Rough idleing then cutting out at speed - ignition, air or fuel, one
of them
won't have all the symtoms as severly as you describe.
Its very strange all the symptoms sort of contradict each other .
+++ maybe it is my descriptions? But it would seem strange that it
could be a combination doens't it? I am now beginning to wonder if it
was this causing the problem the whole time and not the carb though it
was the volvo dealership that told us the carb was warped. It is the
same symptoms that led us to get the carb changed?
I get the feeling you're maybe not making any sensible attempts to
keep it
going by increasing the revs and by trying to push a sick car along at
low
revs you are masking the real symptoms. Having said that it might not
be
useful unless you know what you are doing. Try playing with pumping
the
accelerator or gently increasing your foot pressure on it to encourage
it to
rev up.
+++ well I (we) don't really know what we are doing. But at the end of
the day unless it is to get out of emergency situations I don't care
about making the car 'go'. I just want it fixed so it doesn't happen
again. She is a great car to drive when she is running properly.
As I've already mentioned the 1.7s are quite bad for having very
difficult
to fix problems. A family members car had a similar problem for about
6
months (longer if you include the time they didn't drive it for), I
discovered the problem after the first few months, then took remaing
year or
so to try to eliminate it (was a bit intemittent). I managed a 99%
cure
eventually, I drove the car for about 1 year aswell after taking it on
when
another family member didn't need it. However I could detect that
occasionally it would threaten to come back, but never caused severe
problems. That pretty much sealed the cars fate, and my opinion of
the 1.7.
+++ well exactly. Ours has had this problem for about 2 years or
more..on and off. At other times she is as reliable as anything and
takes a daily run on the motorway to work and back easily in her
stride. I realise that maybe the 1.7 isn't the best engine in the
world but she is our first car and we are reluctant to get rid of her
when the fix might be simple but just hard to find. But we are
beginning to admit that it might be time
I just wish you could take
a look at her and drive her. I feel you could probably tell us in 5
minutes what the mechanic might never find
Any advice would be gratefully received.
Thanks
DD
