Engine won't rev and hunts

[Laird Scooby]

Originally Posted by ANDTWENTY

Thank you for this!! had the car idling for about 5 mins and I have no pressure in that pipe!! think you may be on to something here!

when you say left wheel arch do you mean in the back? if so I don't have a 3 pin I have a 4 pin, the colours are pink brown grey and black and on both sides, any idea if this is right and if so which side is car and tank, mine is mounted vertically with a wire going up and forward and one comes from the right of the car and up into the connector.

addition__

Just tested the wires, with respect to the brown, the pink gives 13 volts but the grey gives only 7, is this an issue being only 7?

Grey is the fuel sender wire to the gauge from the tank sender unit so will vary. If the pink/red one is giving 13V or battery voltage and the pipe doesn't go hard under pressure, the in-tank pump isn't working.

https://www.rockauto.com/en/catalog/...fuel+pump,6256

That should link you to some in-tank (low pressure) pumps for your 940, don't forget to buy the strainer with it as they won't honour the warranty if you don't. If the invoice value is £15 or more, you may have to pay 20% Import VAT on it but still way cheaper than anything we get in the UK, even with S&H (USA version of our P&P) on top. You can even pay by Paypal and the cheapest i saw when i looked just now was £12.44 for a new pump.

You'll also need a new seal, ideally from Volvo, they're about £11 then i'll explain the Volvo Gynaecology Exam, Part One.

I'll try and find the part number for the tank seal from Volvo, it's a common part on most 7/9xx cars so shoold be either in stock or available quickly.

[ANDTWENTY]

Originally Posted by Laird Scooby

Grey is the fuel sender wire to the gauge from the tank sender unit so will vary. If the pink/red one is giving 13V or battery voltage and the pipe doesn't go hard under pressure, the in-tank pump isn't working.

https://www.rockauto.com/en/catalog/...fuel+pump,6256

That should link you to some in-tank (low pressure) pumps for your 940, don't forget to buy the strainer with it as they won't honour the warranty if you don't. If the invoice value is £15 or more, you may have to pay 20% Import VAT on it but still way cheaper than anything we get in the UK, even with S&H (USA version of our P&P) on top. You can even pay by Paypal and the cheapest i saw when i looked just now was £12.44 for a new pump.

You'll also need a new seal, ideally from Volvo, they're about £11 then i'll explain the Volvo Gynaecology Exam, Part One.

I'll try and find the part number for the tank seal from Volvo, it's a common part on most 7/9xx cars so shoold be either in stock or available quickly.

Thank you so mach for all your help, I honestly can't thank you enough!!

[Laird Scooby]

Originally Posted by ANDTWENTY

Thank you so mach for all your help, I honestly can't thank you enough!!

You're very welcome!

[ANDTWENTY]

Just found this on eBay, its double the price but by the time I pay tax and shipping its probably similar, is this the right one do you know? says it fits my car but not sure what they're like.

https://www.ebay.co.uk/itm/New-Genui...QAAOSwAaJaHIpr

[Laird Scooby]

Originally Posted by ANDTWENTY

Just found this on eBay, its double the price but by the time I pay tax and shipping its probably similar, is this the right one do you know? says it fits my car but not sure what they're like.

https://www.ebay.co.uk/itm/New-Genui...QAAOSwAaJaHIpr

Looking at the spec on that one, it would just about cover a carburettor version!

From the listing :


KMS Parts Number VAL347257
Description Fuel Pump
UK Reg No/Vin MUST be supplied The compatibility is only a guide. A UK Reg or VIN number MUST BE SUPPLIED as in many cases there is a "choice" depending on chassis numbers. We cannot be held responsible if this is not supplied or is supplied after despatch.
Chassis Break Chassis number from : 240947/990338, 563922
Note Operating Mode: Electric
Voltage [V]: 12
Flow Rate [l/min.]: 1.25
Pressure [bar]: 0.3

Now check the spec on one of the ones Rock Auto sells :

https://www.rockauto.com/en/moreinfo...&jsn=14&jsn=14

Maximum Free Flow Rate (gph) 40
Maximum Pressure Rate (psi) 7
Minimum Free Flow Rate (gph) 30
Minimum Pressure Rate (psi) 5

Compare the two, first one has a flow rate of 1.25L/min which is 75L/h which is about 16 gallons/hour. Even taking into account US Gallons are 0.8 the size of ours, the 40 Gaall/hr figure equates to 32 Imp Gall/hr so has twice the flow.
Then there's the pressure - 0.3bar on that Valeo one which is about 4-4.5psi - the minimum on the other one is 5psi.

There are reasons for all this, the underbody pump needs a certain flow and pressure to work at its best and that Valeo one won't give it.

If you can find another on fleabay at a sensible price with reasonable flow and pressure and it's listed for the 940, i'm quite happy to double check it for you but wouldn't advise that particular Valeo one at all.

[ANDTWENTY]

Originally Posted by Laird Scooby

Looking at the spec on that one, it would just about cover a carburettor version!

From the listing :


KMS Parts Number VAL347257
Description Fuel Pump
UK Reg No/Vin MUST be supplied The compatibility is only a guide. A UK Reg or VIN number MUST BE SUPPLIED as in many cases there is a "choice" depending on chassis numbers. We cannot be held responsible if this is not supplied or is supplied after despatch.
Chassis Break Chassis number from : 240947/990338, 563922
Note Operating Mode: Electric
Voltage [V]: 12
Flow Rate [l/min.]: 1.25
Pressure [bar]: 0.3

Now check the spec on one of the ones Rock Auto sells :

https://www.rockauto.com/en/moreinfo...&jsn=14&jsn=14

Maximum Free Flow Rate (gph) 40
Maximum Pressure Rate (psi) 7
Minimum Free Flow Rate (gph) 30
Minimum Pressure Rate (psi) 5

Compare the two, first one has a flow rate of 1.25L/min which is 75L/h which is about 16 gallons/hour. Even taking into account US Gallons are 0.8 the size of ours, the 40 Gaall/hr figure equates to 32 Imp Gall/hr so has twice the flow.
Then there's the pressure - 0.3bar on that Valeo one which is about 4-4.5psi - the minimum on the other one is 5psi.

There are reasons for all this, the underbody pump needs a certain flow and pressure to work at its best and that Valeo one won't give it.

If you can find another on fleabay at a sensible price with reasonable flow and pressure and it's listed for the 940, i'm quite happy to double check it for you but wouldn't advise that particular Valeo one at all.

Thanks again for that information!! I didn't realise it had to be as high as that as there is the second pump but guess it does! I'll have another hunt around, I rather get a UK one just so of it's wrong or fails at least it'll be easier to send back but if I can't get anything reasonably priced then I'll go for that.

[mocambique-amazone]

Originally Posted by Laird Scooby

Looking at the spec on that one, it would just about cover a carburettor version!

From the listing :


KMS Parts Number VAL347257
Description Fuel Pump
UK Reg No/Vin MUST be supplied The compatibility is only a guide. A UK Reg or VIN number MUST BE SUPPLIED as in many cases there is a "choice" depending on chassis numbers. We cannot be held responsible if this is not supplied or is supplied after despatch.
Chassis Break Chassis number from : 240947/990338, 563922
Note Operating Mode: Electric
Voltage [V]: 12
Flow Rate [l/min.]: 1.25
Pressure [bar]: 0.3

this one seems to be correct Dave


Now check the spec on one of the ones Rock Auto sells :

https://www.rockauto.com/en/moreinfo...&jsn=14&jsn=14

Maximum Free Flow Rate (gph) 40
Maximum Pressure Rate (psi) 7
Minimum Free Flow Rate (gph) 30
Minimum Pressure Rate (psi) 5

IIRC this are the data's if the Volvo is with one pump only. 1 in tank pump and a filter only under the car

Compare the two, first one has a flow rate of 1.25L/min which is 75L/h which is about 16 gallons/hour. Even taking into account US Gallons are 0.8 the size of ours, the 40 Gaall/hr figure equates to 32 Imp Gall/hr so has twice the flow.
Then there's the pressure - 0.3bar on that Valeo one which is about 4-4.5psi - the minimum on the other one is 5psi.

There are reasons for all this, the underbody pump needs a certain flow and pressure to work at its best and that Valeo one won't give it.

If you can find another on fleabay at a sensible price with reasonable flow and pressure and it's listed for the 940, i'm quite happy to double check it for you but wouldn't advise that particular Valeo one at all.

The lift pump is really only a lift pump. No pressure needed.
The fuel line between the tank and the pump under the car isn't made for high pressure

My data's aren't on my mobile. I will have a closer look at Monday evening earliest.

Have a nice weekend, Kay


I would swap a known working AMM first

[mocambique-amazone]

Originally Posted by ANDTWENTY

Thanks again for that information!! I didn't realise it had to be as high as that as there is the second pump but guess it does! I'll have another hunt around, I rather get a UK one just so of it's wrong or fails at least it'll be easier to send back but if I can't get anything reasonably priced then I'll go for that.

Most of suppliers won't take back electrical parts if they are out of the wrapping, for good reason.
You have to prove the part is faulty by process while the production....

Good luck, Kay

[mocambique-amazone]

OK, let's start

A 1990 940 is a LH2.4 or a diesel

There will be no port for the fuel pressure

This model is with cold start injector

With two fuel pumps

With catalyst

With a ....016 MAF ( AMM)

There is only one variation possible: Regina = mostly found in the great (past) Staates
Regina is crap in my opinion

I don't know the history of this car, especially if "qualified" people did work on.
To be clear: "not qualified" you will find even at a pro-workshop, even at a volvo dealer workshop
I did solve a looooooot of hughe and unbelievable faults done by "pros"

If there is no code at the diode inside the engine bay and no warning light at the dashboard I would say the AMM is the faulty part.
Don't try to clean this. The LH2.4 does clean them by there own by heating them up and burn the stuff on the wire away.

Cap and rotor : only made by Bosch, nothing else I use
All sensors : the same, Bosch and really nothing else. I would prefer even a used Bosch one than a new s... made by all others, sorry.

If you follow the instructions about the diagnostic box in the engine bay you will be able to do a diagnose of the TPS and other stuff too.
Most people know the fault codes only.

Good luck, Kay

[ANDTWENTY]

Originally Posted by mocambique-amazone

The lift pump is really only a lift pump. No pressure needed.
The fuel line between the tank and the pump under the car isn't made for high pressure

My data's aren't on my mobile. I will have a closer look at Monday evening earliest.

Have a nice weekend, Kay


I would swap a known working AMM first

Thank you for this, so ruffly speaking then would you say that one I found is what you'd expect output wise? Presumably if it's low pressure then pinching the line may not be conclusive enough? Is there another way to test the pump without taking it all out the tank?

Is there a way to test the AMM as getting hold of a new one is expensive and second hand ones seem hard to come by