fuel pump relay again. - Page 2

classicswede · Apr 23rd, 2024, 18:45

Quote:

Originally Posted by Rversteeg

The 2 seconds priming function is not in the relay itsef, but in the ECU.
Th.

Can you show me and the rest of the world where the ecu is

Rversteeg · Apr 24th, 2024, 11:35

The ECU I am referring to is the LH-computer for the fuel injection system, located just behind the right front wheel arch, near the driver's right foot.

Chris1Roll · Apr 24th, 2024, 20:38

Which offgrid does not have on his B200E Kjet engine.

classicswede · Apr 25th, 2024, 00:19

Quote:

Originally Posted by Rversteeg

The ECU I am referring to is the LH-computer for the fuel injection system, located just behind the right front wheel arch, near the driver's right foot.

The thread is all about a K jetronic car so no computer.
The green relay of K jet as already described primes the fuel pump and has the safety car. On the other hand LH does this with the ECU hence using the white relay

Rversteeg · Apr 25th, 2024, 08:31

Quote:

Can you show me and the rest of the world where the ecu is

Why then ask if you already know?

Offgrid · Apr 25th, 2024, 08:55

Here are the images of the two failed relays -

For a larger image, then please click -> failed 740 fuel pump relays

The image on the left is the one that pumps when the ignition is off, and doesn't when the ignition is on.This may follow the guidelines of our current government, but it isn't quite what is needed in a Volvo fuel system. You can see the disconnected wire in the right hand image - it is the thick black one on pin 30. The equivalent is braided copper in the left image. It should be a simple task to resolder the connection, and I'll post the results when I get round to it.

The more interesting project is the repair of the older relay. My guess is that the component with the copper coil has failed, and I wonder if I can purchase a new "black box" as used on the later unit, and just solder that onto the board. The circuit board and other components look the same as the newer one.

I found this on Google - https://www.aliexpress.com/item/4001341897537.html
Has anybody used Ali Express?

360beast · Apr 25th, 2024, 09:43

Good old professional parts sweden junk strikes again.

classicswede · Apr 25th, 2024, 10:09

Quote:

Originally Posted by 360beast

Good old professional parts sweden junk strikes again.

They are not great but Volvo have now deleted the original part. I have looked and can not get the original from any other source I have seen

Offgrid · Apr 25th, 2024, 10:31

This is the part I bought on Ebay - https://www.ebay.co.uk/itm/364407446703
It seems to be working fine, but I can't comment on the longevity and reliability of the part.

Ebay seems to have updated their compatibility check. They now state that it fits ( and presumably works) in my estate ( The Hoe).

Chris1Roll · Apr 25th, 2024, 11:02

According to the history, the relay in my car was replaced in 2006 (only 27k miles ago). I assume with a non-volvo one as the pumps do not prime with ignition on.

Since the Volvo part is now NLA, I've just bought the same relay (from parts monster) to keep in the car as offgrid has, and predictably enough it is a PPS part.

I was originally thinking to swap it in and see if I get a quicker start if it primes the pumps, but for now I think I'll stick with whats in there.

Perhaps I should at least check if it works at all!

A 2-pronged jumper wire with male spade terminals to go between the sockets for terminals 30 and 87+87b might be a more reliable get-you-home option.

Apr 24th, 2024, 11:35	#12
Rversteeg Master Member Last Online: Yesterday 16:56 Join Date: Feb 2006 Location: Amersfoort (NL)	Ecu The ECU I am referring to is the LH-computer for the fuel injection system, located just behind the right front wheel arch, near the driver's right foot.

Apr 25th, 2024, 08:55	#16
Offgrid Offgrid camper Last Online: Today 16:31 Join Date: Apr 2022 Location: Havant	Here are the images of the two failed relays - For a larger image, then please click -> failed 740 fuel pump relays The image on the left is the one that pumps when the ignition is off, and doesn't when the ignition is on.This may follow the guidelines of our current government, but it isn't quite what is needed in a Volvo fuel system. You can see the disconnected wire in the right hand image - it is the thick black one on pin 30. The equivalent is braided copper in the left image. It should be a simple task to resolder the connection, and I'll post the results when I get round to it. The more interesting project is the repair of the older relay. My guess is that the component with the copper coil has failed, and I wonder if I can purchase a new "black box" as used on the later unit, and just solder that onto the board. The circuit board and other components look the same as the newer one. I found this on Google - https://www.aliexpress.com/item/4001341897537.html Has anybody used Ali Express? __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars Last edited by Offgrid; Apr 25th, 2024 at 09:16.

Apr 25th, 2024, 10:31	#19
Offgrid Offgrid camper Last Online: Today 16:31 Join Date: Apr 2022 Location: Havant	This is the part I bought on Ebay - https://www.ebay.co.uk/itm/364407446703 It seems to be working fine, but I can't comment on the longevity and reliability of the part. Ebay seems to have updated their compatibility check. They now state that it fits ( and presumably works) in my estate ( The Hoe). __________________ Cinderella ( Cinders ) - 1988 Volvo 740 saloon with B230E engine The Hoe - 1990 Volvo 740 estate with B200E engine The House - 2005 LDV Convoy hightop with Ford Transit turbo engine. Save Old Cars Last edited by Offgrid; Apr 25th, 2024 at 10:33.

Apr 24th, 2024, 20:38	#13
Chris1Roll Senior Member Last Online: Yesterday 20:28 Join Date: Aug 2006 Location: Cannington	Which offgrid does not have on his B200E Kjet engine.

Apr 25th, 2024, 09:43	#17
360beast Go redblock or go home Last Online: Today 18:19 Join Date: Feb 2012 Location: UK	Good old professional parts sweden junk strikes again.

Apr 25th, 2024, 11:02	#20
Chris1Roll Senior Member Last Online: Yesterday 20:28 Join Date: Aug 2006 Location: Cannington	According to the history, the relay in my car was replaced in 2006 (only 27k miles ago). I assume with a non-volvo one as the pumps do not prime with ignition on. Since the Volvo part is now NLA, I've just bought the same relay (from parts monster) to keep in the car as offgrid has, and predictably enough it is a PPS part. I was originally thinking to swap it in and see if I get a quicker start if it primes the pumps, but for now I think I'll stick with whats in there. Perhaps I should at least check if it works at all! A 2-pronged jumper wire with male spade terminals to go between the sockets for terminals 30 and 87+87b might be a more reliable get-you-home option.

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