fuel flow problem - Page 2

PetrolFeet · 25th January 2023, 08:27

I'm not convinced I don't need a new pump, as I'm not sure I could rely on it.
Why was it yininginging so much before, when starting?
Why did it yingyivroom today?
Is there a fault in the fuel transfer plumbing?
Note, the old yingyings needed for starting was regardless if there was 1/2 tank or vapours.
I wonder if a smaller tank can be fitted? Never filled it more than half way since I had it, and the raised saddle and fuel transfer pipery seems to be another source of grief.

PetrolFeet · 25th January 2023, 09:27

Another thought, I've read, probably on this very forum, that there are two fuel level senders in the tank.
Is it possible to take the readings separately?
That way, the fuel level on both sides can be monitored.
If there is a fuel transfer problem, this would greatly speed the diagnosis.
Anyone got any knowledge about this (even if only wire colours)?

Also, is this in any way related to the CDTI fault about only running when over 1/4 tank I've read about?

Further also thought, sometimes the red fuel light goes on when the needle is fairly high, sometimes it is off when the needle if fairly low.
Perhaps the light is triggered by the signal on the pump side (the light came on a couple of miles before I pulled up the night before) but the needle was above the red light area. Maybe the needle gives an average reading, but the lamp uses offside sender only?

Matt_75 · 25th January 2023, 10:12

Regarding the fuel level sensors, the IPK diagnostic mode is capable of telling you what each sensor is reading. Have a look at section 6 of this guide: https://www.the75andztclub.co.uk/for...ad.php?t=55585

PetrolFeet · 25th January 2023, 10:18

Cheers Matt 75, nut I'm thinking old skool, analogue solution (I'm an analogue kinda guy). I can take ohmages from various wires and do my own math, I'm hoping to find out what wires to probe. Are the two signals combined internally (i.e. have to fiddle with the wiring in the tank) or externally (i.e. both signals will be on different wires somewhere outside the tank)?

Matt_75 · 25th January 2023, 10:50

I think the signals come out separate pins of the same connector (the one on top of the pump assembly, under the rear seat), but I'm not 100% on that. The electrical diagram (see page 98 of the pdf) might be helpful: https://the75andztclub.co.uk/forum/s...=280437&page=2

PetrolFeet · 25th January 2023, 12:25

https://www.the75andztclub.co.uk/for...mg&imgid=30500

PetrolFeet · 25th January 2023, 12:26

Hi does anyone know how to attach pictures?
The one above does not look like a picture, what have I done wrong?

PetrolFeet · 25th January 2023, 12:54

PetrolFeet · 25th January 2023, 12:57

Figured it out, as you can see, thanks Reebs, the link to that wasn't working before.

Anyhow, looks like the two senders have individual outputs: pins 6 and 3, and also pins 4 and 1.
So, I can now take readings from either sender.
If I have the chance I'll get readings from my car and post them here.
Still reckon it's a fuel transfer problem.

PetrolFeet · 25th January 2023, 13:01

Oh, and muchas gracias to T-Cut for the original and Suzublu for the link.

25th January 2023, 08:27	#11
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	I'm not convinced I don't need a new pump, as I'm not sure I could rely on it. Why was it yininginging so much before, when starting? Why did it yingyivroom today? Is there a fault in the fuel transfer plumbing? Note, the old yingyings needed for starting was regardless if there was 1/2 tank or vapours. I wonder if a smaller tank can be fitted? Never filled it more than half way since I had it, and the raised saddle and fuel transfer pipery seems to be another source of grief.

25th January 2023, 09:27	#12
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	Another thought, I've read, probably on this very forum, that there are two fuel level senders in the tank. Is it possible to take the readings separately? That way, the fuel level on both sides can be monitored. If there is a fuel transfer problem, this would greatly speed the diagnosis. Anyone got any knowledge about this (even if only wire colours)? Also, is this in any way related to the CDTI fault about only running when over 1/4 tank I've read about? Further also thought, sometimes the red fuel light goes on when the needle is fairly high, sometimes it is off when the needle if fairly low. Perhaps the light is triggered by the signal on the pump side (the light came on a couple of miles before I pulled up the night before) but the needle was above the red light area. Maybe the needle gives an average reading, but the lamp uses offside sender only?

25th January 2023, 10:12	#13
Matt_75 Gets stuck in 75 Saloon Join Date: Apr 2022 Location: North Somerset Posts: 548 Thanks: 13 Thanked 20 Times in 8 Posts	Regarding the fuel level sensors, the IPK diagnostic mode is capable of telling you what each sensor is reading. Have a look at section 6 of this guide: https://www.the75andztclub.co.uk/for...ad.php?t=55585

25th January 2023, 10:18	#14
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	Cheers Matt 75, nut I'm thinking old skool, analogue solution (I'm an analogue kinda guy). I can take ohmages from various wires and do my own math, I'm hoping to find out what wires to probe. Are the two signals combined internally (i.e. have to fiddle with the wiring in the tank) or externally (i.e. both signals will be on different wires somewhere outside the tank)?

25th January 2023, 10:50	#15
Matt_75 Gets stuck in 75 Saloon Join Date: Apr 2022 Location: North Somerset Posts: 548 Thanks: 13 Thanked 20 Times in 8 Posts	I think the signals come out separate pins of the same connector (the one on top of the pump assembly, under the rear seat), but I'm not 100% on that. The electrical diagram (see page 98 of the pdf) might be helpful: https://the75andztclub.co.uk/forum/s...=280437&page=2

25th January 2023, 12:25	#16
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	https://www.the75andztclub.co.uk/for...mg&imgid=30500

25th January 2023, 12:26	#17
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	Hi does anyone know how to attach pictures? The one above does not look like a picture, what have I done wrong?

25th January 2023, 12:54	#18
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts

25th January 2023, 12:57	#19
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	Figured it out, as you can see, thanks Reebs, the link to that wasn't working before. Anyhow, looks like the two senders have individual outputs: pins 6 and 3, and also pins 4 and 1. So, I can now take readings from either sender. If I have the chance I'll get readings from my car and post them here. Still reckon it's a fuel transfer problem.

25th January 2023, 13:01	#20
PetrolFeet Regular poster rover 75 kv6 Join Date: Jan 2023 Location: Kettering Posts: 30 Thanks: 0 Thanked 0 Times in 0 Posts	Oh, and muchas gracias to T-Cut for the original and Suzublu for the link.