98 940 2.3lpt auto stalling, not starting

[zchael6]

Right so I’ve been doing a bit of work in the car as might have seen on other threads. Cam belt and aux belts, crank breather system, part change on auto transmission fluid. I filled the car up with half a tank of fuel, and drove it for 20 miles. It stalled at the top of a gentle hill. We rolled to the side, waited an hour then started it up and drove The remaining bit home.

Now today it’s stalled on a hill again. Although this time I’ve started it up and it’s stalled again. Now all it will do is 100m or so before cutting out.

It seems to cut out under acceleration. It’s just completely dies. Electrics and everything. I thought it might be water in the fuel so I added some meths. This seems to have made it worse?

I’m wondering whether there is air getting into the fuel line?

Any help would be appreciated.

Will

[Forrest]

Does the rev counter drop to zero just before it stalls? If so, that would point more to the crank position sensor on top of the bell housing. A bit difficult to reach and even harder to see. The wire tends to wear where it joins the sensor.

There are other things that will cause this related to both ignition and fuel. The other two I have personal experience of are failure of the in-tank fuel pump and problems with the fuel pump relay. With fuel feed problems you’re more likely to see the dash warning lights illuminate before the revs drop to zero.

A 1998 car will have a single high-pressure fuel pump in the tank. Early cars have a low pressure pump in the tank and a main pump under the car. You should be able to hear if the pump starts when you turn the key. It’s failure to do so could be either the relay (easy to change) or the pump (less easy to change). Stalling on a hill might be a clue the problem is fuel related but there are no guaranteed shortcuts to pinpointing the fault.

For other possible causes try the FAQ or await replies from folk who’ve experienced them.

[zchael6]

Originally Posted by Forrest

Does the rev counter drop to zero just before it stalls? If so, that would point more to the crank position sensor on top of the bell housing. A bit difficult to reach and even harder to see. The wire tends to wear where it joins the sensor.

There are other things that will cause this related to both ignition and fuel. The other two I have personal experience of are failure of the in-tank fuel pump and problems with the fuel pump relay. With fuel feed problems you’re more likely to see the dash warning lights illuminate before the revs drop to zero.

A 1998 car will have a single high-pressure fuel pump in the tank. Early cars have a low pressure pump in the tank and a main pump under the car. You should be able to hear if the pump starts when you turn the key. It’s failure to do so could be either the relay (easy to change) or the pump (less easy to change). Stalling on a hill might be a clue the problem is fuel related but there are no guaranteed shortcuts to pinpointing the fault.

For other possible causes try the FAQ or await replies from folk who’ve experienced them.

The rev counter just drops to zero yes. The first job I did on the car was the cam belt so perhaps it is something to do with the crank position sensor? When I ddI the cam belt I took the belt off thinking all the timing marks were aligned but I was looking at the wrong white blob on the cam shaft pully and so had to align the marks with the belt off. The problem seems to having gotten worse since I added some meths to the tank (thinking it was water in the fuel). Tonight I just managed to limp home. It wouldn’t occasionally get going and id do another 500m down the road before it cut out again. Had to push it the last 100m.

Thanks for the reply. Really appreciate it

[aardvarkash10]

CPS for sure. Its an easy fix - the very first guide in the Articles page explains it.

If you are feeling motivated, its probably worth replacing hte ignition amp at the same time. There are plenty of examples (including me!) where both failed within days of each other.

The in-tank pump is a biatch to access, but is also on the "fails after 20 years" list from my experience. Again, if you have a spare 1/2 a day and need to practice your gynaelogical skills, its worth replacing. I got mine from a Canadian business _ can't remember the name offhand - it was cheap and is working fine after 12 months. If you search my threads you'll probably find more info on it.

[zchael6]

Originally Posted by aardvarkash10

CPS for sure. Its an easy fix - the very first guide in the Articles page explains it.

Thanks everyone. Part ordered. Thanks again

[Laird Scooby]

Originally Posted by zchael6

Thanks everyone. Part ordered. Thanks again

From everything i've just read, i'd agree with the CPS diagnosis. However i'd like to know if you were going uphill or down when it cut out and how much meths you put in the tank and how full the tank was when you did it?

[zchael6]

Originally Posted by Laird Scooby

From everything i've just read, i'd agree with the CPS diagnosis. However i'd like to know if you were going uphill or down when it cut out and how much meths you put in the tank and how full the tank was when you did it?

Thanks for the reply. I was going uphill the first few times the stall happened. It was after cam belt change and transmission fluid change. It’s gotten worse since I changed the crank breather hoses and added 1.5lts of meths to my fuel tank which had half a tank of fuel in it.

I’ve seen where the cps is on photos online and I’m wondered whether I spilled some atf onto it when doing the fluid part change. I sucked a few litres out with a pump and put the same back in with a funnel through the tranny fluid dip stick tube.

When I did the crank breather hoses yesterday I uncoupled the heater hose coming off the heater valve and a good bit of coolant came out and probably went on the bell housing.

Just wondering whether these two instances of fluid splashing down towards the bell housing has cooked the sensor.

I’m going to see if I can visualise the cps where it enters the bell housing and maybe remove it, assess its condition.

[360beast]

Here you go

https://www.volvoforums.org.uk/showthread.php?t=286054

[Laird Scooby]

Originally Posted by zchael6

Thanks for the reply. I was going uphill the first few times the stall happened. It was after cam belt change and transmission fluid change. It’s gotten worse since I changed the crank breather hoses and added 1.5lts of meths to my fuel tank which had half a tank of fuel in it.

I’ve seen where the cps is on photos online and I’m wondered whether I spilled some atf onto it when doing the fluid part change. I sucked a few litres out with a pump and put the same back in with a funnel through the tranny fluid dip stick tube.

When I did the crank breather hoses yesterday I uncoupled the heater hose coming off the heater valve and a good bit of coolant came out and probably went on the bell housing.

Just wondering whether these two instances of fluid splashing down towards the bell housing has cooked the sensor.

I’m going to see if I can visualise the cps where it enters the bell housing and maybe remove it, assess its condition.

First of all, going uphill will send all the water/condensation to the back of the tank to exactly where the fuel pump is, hence you were potentially dragging water through.
Sadly the amount of meths you added to that amount of fuel will do nothing.

Nada, zilch, zip.

Half a tank is at least 30L, 1.5L of meths is about 5% concentration. The optimum for removal of condensation/water is 10% meths to petrol so at 1/4 tank by the gauge, there is 15-20L left. Adding 2L of meths gives you that 10% concentration.
Note these figures are for the older 7/9xx models with a 60L tank, i think later 940s had a larger tank so you may have to adjust the figures, assuming you can get hold of any meths. Toolstation refunded the portion of my order that represented the meths last night so it seems there's also a world shortage of meths as well as tolet rolls, washing up liquid, pasta, rice and so on.

Splashing ATF or coolant on the CPS won't cause these problems and removing it won't tell you anymore than you can already see. It's the cable that goes usually so you should be able to find and see that, if you've ordered a new one you'll find out why i'm saying don't remove it now. Wait until you fit the new one!

[zchael6]

Originally Posted by Laird Scooby

First of all, going uphill will send all the water/condensation to the back of the tank to exactly where the fuel pump is, hence you were potentially dragging water through.
Sadly the amount of meths you added to that amount of fuel will do nothing.

Nada, zilch, zip.

Half a tank is at least 30L, 1.5L of meths is about 5% concentration. The optimum for removal of condensation/water is 10% meths to petrol so at 1/4 tank by the gauge, there is 15-20L left. Adding 2L of meths gives you that 10% concentration.
Note these figures are for the older 7/9xx models with a 60L tank, i think later 940s had a larger tank so you may have to adjust the figures, assuming you can get hold of any meths. Toolstation refunded the portion of my order that represented the meths last night so it seems there's also a world shortage of meths as well as tolet rolls, washing up liquid, pasta, rice and so on.

Splashing ATF or coolant on the CPS won't cause these problems and removing it won't tell you anymore than you can already see. It's the cable that goes usually so you should be able to find and see that, if you've ordered a new one you'll find out why i'm saying don't remove it now. Wait until you fit the new one!

Ok well I’m relieved the meths probs isn’t doing anything bad. Yes i bought all the meths the village shop had an bunged it in, thinking it was better than nothing.

Also relieved to hear the splashing of fluid isn’t likely to do anything!

I have located the sensor, I’m quite tall so i can reach the bolt that attaches it to the bell housing quite easily. There is indeed a nick in the outer black rubber sheath near where it plugs in bellow the scuttle panel meaning i can see the two cables inside.

The car started this morning. I just repositioned it on the drive. It seems that it is a problem which takes over when the engine bay gets to a certain temp?

Have an aftermarket sensor coming tomorrow so will remove old one and install new one then. Thanks for the time to reply to my post!