1992 Volvo 940

Help!! I'm tearing my hair out to find the reason for my 940 stalling in
very hot weather.It happens every summer when the temp gets around 40c. I
assume its's caused by vapour locks. If you open the bonnet and let it cool
for 15 mins it runs ok for a few kms before it happens again.
All other times it runs perfectly. I have "googled " this problem with no
real concrete answers. I can only think of getting the fuel pumps replaced
to possibly cure this problem, but I would hate to go to that expense and
not getting a fix.
All ideas welcome!!!!

Kim Slyns wrote:
> Help!! I'm tearing my hair out to find the reason for my 940 stalling in
> very hot weather.It happens every summer when the temp gets around 40c. I
> assume its's caused by vapour locks. If you open the bonnet and let it cool
> for 15 mins it runs ok for a few kms before it happens again.
> All other times it runs perfectly. I have "googled " this problem with no
> real concrete answers. I can only think of getting the fuel pumps replaced
> to possibly cure this problem, but I would hate to go to that expense and
> not getting a fix.
> All ideas welcome!!!!
>
>

I seem to recall something about ignition power stages (think
ignition coil, but different construction) failing from heat. Hopefully
someone will confirm this.

The Ignition Amplifier is located between the air filter box and the inner
wing skin. It usually has problems caused by it's earthing as it is mounted
on a "heat-sink". Cleaning the connector and also the heat sink will often
cure this problem. The amplifier is driven from the ICU and bumps up the
power to drive the coil.
All the best, Peter.


"Leftie" <(E-Mail Removed)> wrote in message
news:YoL0n.6176$_(E-Mail Removed)...
> Kim Slyns wrote:
>> Help!! I'm tearing my hair out to find the reason for my 940 stalling in
>> very hot weather.It happens every summer when the temp gets around 40c. I
>> assume its's caused by vapour locks. If you open the bonnet and let it
>> cool for 15 mins it runs ok for a few kms before it happens again.
>> All other times it runs perfectly. I have "googled " this problem with no
>> real concrete answers. I can only think of getting the fuel pumps
>> replaced to possibly cure this problem, but I would hate to go to that
>> expense and not getting a fix.
>> All ideas welcome!!!!
>
> I seem to recall something about ignition power stages (think ignition
> coil, but different construction) failing from heat. Hopefully someone
> will confirm this.

Leftie wrote:
> Kim Slyns wrote:
>> Help!! I'm tearing my hair out to find the reason for my 940 stalling
>> in very hot weather.It happens every summer when the temp gets around
>> 40c. I assume its's caused by vapour locks. If you open the bonnet and
>> let it cool for 15 mins it runs ok for a few kms before it happens again.
>> All other times it runs perfectly. I have "googled " this problem with
>> no real concrete answers. I can only think of getting the fuel pumps
>> replaced to possibly cure this problem, but I would hate to go to that
>> expense and not getting a fix.
>> All ideas welcome!!!!
>>
>
> I seem to recall something about ignition power stages (think
> ignition coil, but different construction) failing from heat. Hopefully
> someone will confirm this.


The ignition amplifier is the electronic module that takes the logic
level signal from the ignition computer and switches power to the
ignition coil. When they fail, they do usually cause occasional stalling
at first. A way to tell is that the tach needle will fall like a rock
when the engine stalls.

If the in tank pump fails the engine gets little fuel and if the tank is
low your in trouble happened in my wifes car



"James Sweet" <(E-Mail Removed)> wrote in message
news:hi0uno$ul0$(E-Mail Removed)...
> Leftie wrote:
>> Kim Slyns wrote:
>>> Help!! I'm tearing my hair out to find the reason for my 940 stalling in
>>> very hot weather.It happens every summer when the temp gets around 40c.
>>> I assume its's caused by vapour locks. If you open the bonnet and let it
>>> cool for 15 mins it runs ok for a few kms before it happens again.
>>> All other times it runs perfectly. I have "googled " this problem with
>>> no real concrete answers. I can only think of getting the fuel pumps
>>> replaced to possibly cure this problem, but I would hate to go to that
>>> expense and not getting a fix.
>>> All ideas welcome!!!!
>>>
>>
>> I seem to recall something about ignition power stages (think ignition
>> coil, but different construction) failing from heat. Hopefully someone
>> will confirm this.
>
>
> The ignition amplifier is the electronic module that takes the logic level
> signal from the ignition computer and switches power to the ignition coil.
> When they fail, they do usually cause occasional stalling at first. A way
> to tell is that the tach needle will fall like a rock when the engine
> stalls.

Thanks to all for your help. The problem is still "work in progress" but at
least I have some clues to go by.

"Jon Robertson" <(E-Mail Removed)> wrote in message
news:4b45df7e$0$6096$(E-Mail Removed) ...
> If the in tank pump fails the engine gets little fuel and if the tank is
> low your in trouble happened in my wifes car
>
>
>
> "James Sweet" <(E-Mail Removed)> wrote in message
> news:hi0uno$ul0$(E-Mail Removed)...
>> Leftie wrote:
>>> Kim Slyns wrote:
>>>> Help!! I'm tearing my hair out to find the reason for my 940 stalling
>>>> in very hot weather.It happens every summer when the temp gets around
>>>> 40c. I assume its's caused by vapour locks. If you open the bonnet and
>>>> let it cool for 15 mins it runs ok for a few kms before it happens
>>>> again.
>>>> All other times it runs perfectly. I have "googled " this problem with
>>>> no real concrete answers. I can only think of getting the fuel pumps
>>>> replaced to possibly cure this problem, but I would hate to go to that
>>>> expense and not getting a fix.
>>>> All ideas welcome!!!!
>>>>
>>>
>>> I seem to recall something about ignition power stages (think
>>> ignition coil, but different construction) failing from heat. Hopefully
>>> someone will confirm this.
>>
>>
>> The ignition amplifier is the electronic module that takes the logic
>> level signal from the ignition computer and switches power to the
>> ignition coil. When they fail, they do usually cause occasional stalling
>> at first. A way to tell is that the tach needle will fall like a rock
>> when the engine stalls.
>
>

yea...i think you have two fuel pumps...on in the tank and
one under the drivers seat...acessed from crawling under the
car...i used to have to tap mine every once and a while to
bump it a bit into running ok...this, the one under the drivers
seat...i think we could tell it was not right by pulling a fuel line
and seeing if gas was getting pumped at the right pressure....

good luck...






On Jan 20, 4:47*pm, "Kim Slyns" <kime...@internode.on.net> wrote:
> Thanks to all for your help. The problem is still "work in progress" but at
> least I have some clues to go by.
>
> "Jon Robertson" <jon5...@optusnet.com.au> wrote in message
>
> news:4b45df7e$0$6096$(E-Mail Removed) ...
>
>
>
> > If the in tank pump fails the engine gets little fuel and if the tank is
> > low your in trouble happened in my wifes car
>
> > "James Sweet" <jamesrsw...@gmail.com> wrote in message
> >news:hi0uno$ul0$(E-Mail Removed)...
> >> Leftie wrote:
> >>> Kim Slyns wrote:
> >>>> Help!! I'm tearing my hair out to find the reason for my 940 stalling
> >>>> in very hot weather.It happens every summer when the temp gets around
> >>>> 40c. I assume its's caused by vapour locks. If you open the bonnet and
> >>>> let it cool for 15 mins it runs ok for a few kms before it happens
> >>>> again.
> >>>> All other times it runs perfectly. I have "googled " this problem with
> >>>> no real concrete answers. I can only think of getting the fuel pumps
> >>>> replaced to possibly cure this problem, but I would hate to go to that
> >>>> expense and not getting a fix.
> >>>> All ideas welcome!!!!
>
> >>> * *I seem to recall something about ignition power stages (think
> >>> ignition coil, but different construction) failing from heat. Hopefully
> >>> someone will confirm this.
>
> >> The ignition amplifier is the electronic module that takes the logic
> >> level signal from the ignition computer and switches power to the
> >> ignition coil. When they fail, they do usually cause occasional stalling
> >> at first. A way to tell is that the tach needle will fall like a rock
> >> when the engine stalls.- Hide quoted text -
>
> - Show quoted text -

~^ beancounter ~^ wrote:
> yea...i think you have two fuel pumps...on in the tank and
> one under the drivers seat...acessed from crawling under the
> car...i used to have to tap mine every once and a while to
> bump it a bit into running ok...this, the one under the drivers
> seat...i think we could tell it was not right by pulling a fuel line
> and seeing if gas was getting pumped at the right pressure....
>
> good luck...
>
>
>
>
>
>
> On Jan 20, 4:47 pm, "Kim Slyns" <kime...@internode.on.net> wrote:
>> Thanks to all for your help. The problem is still "work in progress" but at
>> least I have some clues to go by.
>>
>> "Jon Robertson" <jon5...@optusnet.com.au> wrote in message
>>
>> news:4b45df7e$0$6096$(E-Mail Removed) ...
>>
>>
>>
>>> If the in tank pump fails the engine gets little fuel and if the tank is
>>> low your in trouble happened in my wifes car
>>> "James Sweet" <jamesrsw...@gmail.com> wrote in message
>>> news:hi0uno$ul0$(E-Mail Removed)...
>>>> Leftie wrote:
>>>>> Kim Slyns wrote:
>>>>>> Help!! I'm tearing my hair out to find the reason for my 940 stalling
>>>>>> in very hot weather.It happens every summer when the temp gets around
>>>>>> 40c. I assume its's caused by vapour locks. If you open the bonnet and
>>>>>> let it cool for 15 mins it runs ok for a few kms before it happens
>>>>>> again.
>>>>>> All other times it runs perfectly. I have "googled " this problem with
>>>>>> no real concrete answers. I can only think of getting the fuel pumps
>>>>>> replaced to possibly cure this problem, but I would hate to go to that
>>>>>> expense and not getting a fix.
>>>>>> All ideas welcome!!!!
>>>>> I seem to recall something about ignition power stages (think
>>>>> ignition coil, but different construction) failing from heat. Hopefully
>>>>> someone will confirm this.
>>>> The ignition amplifier is the electronic module that takes the logic
>>>> level signal from the ignition computer and switches power to the
>>>> ignition coil. When they fail, they do usually cause occasional stalling
>>>> at first. A way to tell is that the tach needle will fall like a rock
>>>> when the engine stalls.- Hide quoted text -
>> - Show quoted text -
>


You can pull the return line from the pressure regulator and verify that
you have a good flow. I had a pump fail once in a way that it sounded
like it was running but it wasn't pumping any fuel. The little nubs on
the motor armature had broken off so the pump mechanism wasn't turning.