Low fuel pressure, or MAF?

Bogbrush82 · 23rd June 2017, 23:16

At the last Midland nano meet I had new O-rings fitted by Arctic ( Big thanks for that BTW

) and everything seemed fine afterwards. Engine was quieter, smoother and more economical (seemed to warm up quicker as well).

BUT!

For the past couple of days I've suffered what appears to be turbo lag. Now Arctic did notice that starting my car seemed to take longer than usual, and that the rear fuel pump was potentially a culprit. Could the two problems be linked? Would a faulty rear pump cause turbo lag type symptoms, or could it be just a coincidence and it's just the MAF sensor has decided to throw a spanner in the works? Also being a MK2 with the chassis number starting 32, does my car actually have a rear pump?

sworks · 23rd June 2017, 23:20

Both mk1 and mk2's have a rear pump, the mk2 generally doesn't have the under bonnet pump. You can disconnect the maf and see if the car drives differently. If a mk2 with a boost sensor you may get a fault code. If it takes longer to start than normal then it's maybe worth an injector leak back test

Bogbrush82 · 23rd June 2017, 23:35

Apologies for that - I knew that they all had pumps in the rear, but for some reason my Brain lost all it's cells and I realised after I posted it that I should have asked about both pumps instead of just the rear one

Arctic · 25th June 2017, 10:02

Hi David.
From memory I think I commented that you car being an 04 plate had the under bonnet pump as well as the in tank pump, if you remember I said unplug the under bonnet pump when it is quite at home and check to see if you can hear the in tank pump working, You can check the UB pump also does it seem noisy

It could also be the HPFP regulator O-rings, removal of the starter required for access to check.

Do you also remember I commented on the intercooler hose being past it's best, are you getting any black smoke on acceleration, if so the hose could have a split in it.

As above it could be the maf if so unplug it and see if it makes any difference.

Bogbrush82 · 25th June 2017, 11:04

Thanks Arctic. Think I'll spend the day checking it out and let you know what I find.

Bogbrush82 · 25th June 2017, 11:58

Forgot to mention - I've not noticed any black smoke, except when flooring it. Can the pipe still fail and not cause any?

bl52krz · 26th June 2017, 21:16

What can happen is that because the inter cooler pipe is 'soft' from age, when you floor it, it 'blows up'and you lose some power.

Bogbrush82 · 27th June 2017, 11:05

Quick update - Turbo lag almost completely gone after disconnecting the MAF, but power has gone down a fraction as a result.

HarryM1BYT · 27th June 2017, 11:20

Quote:

Originally Posted by Bogbrush82

Quick update - Turbo lag almost completely gone after disconnecting the MAF, but power has gone down a fraction as a result.

That is normal, when the MAF has failed. You need a new proper and genuine Bosch MAF.

The original intercooler pipe can not only blow up, but it can become porous - usually indicated by the outer of the pipe being covered with a coating of oily gunge, including the back of the nearside headlight.

There is a company which supplies both a much better quality pipe, but cheaper than OEM pipe too.

Arctic · 27th June 2017, 12:50

Quote:

Originally Posted by Bogbrush82

Quick update - Turbo lag almost completely gone after disconnecting the MAF, but power has gone down a fraction as a result.

HI David.
Now you know the reason I said to you at the nano meet to replace the air intake as it had been cut off, due to someone doing the mod thinking it would get more air

No it damages the MAF, if you have time try and get over to mine and get it replaced.

I could also possibly help you out with the MAF drop me a PM if interested Arctic.

23rd June 2017, 23:16	#1
Bogbrush82 I really should get out more....... BMW X3 2.0D Join Date: May 2017 Location: Tipton Posts: 2,383 Thanks: 51 Thanked 765 Times in 421 Posts	Low fuel pressure, or MAF? At the last Midland nano meet I had new O-rings fitted by Arctic ( Big thanks for that BTW ) and everything seemed fine afterwards. Engine was quieter, smoother and more economical (seemed to warm up quicker as well). BUT! For the past couple of days I've suffered what appears to be turbo lag. Now Arctic did notice that starting my car seemed to take longer than usual, and that the rear fuel pump was potentially a culprit. Could the two problems be linked? Would a faulty rear pump cause turbo lag type symptoms, or could it be just a coincidence and it's just the MAF sensor has decided to throw a spanner in the works? Also being a MK2 with the chassis number starting 32, does my car actually have a rear pump? __________________ Current car: BMW x3 2.0d (The one with the M47 engine!) Rolled off the line on December 14th, 2004. Last edited by Bogbrush82; 23rd June 2017 at 23:19..

23rd June 2017, 23:20	#2
sworks Been absent for a while… Rover 75 Tourer, Classic mini Cooper S, Abarth 595 competizione, MG TF and a Hyundai Tucson PHEV Join Date: Feb 2007 Location: Cumbria Posts: 13,065 Thanks: 1,033 Thanked 1,686 Times in 1,040 Posts	Both mk1 and mk2's have a rear pump, the mk2 generally doesn't have the under bonnet pump. You can disconnect the maf and see if the car drives differently. If a mk2 with a boost sensor you may get a fault code. If it takes longer to start than normal then it's maybe worth an injector leak back test __________________ ................................................. 'Marmite' Possibly one of the most famous 75 tourers produced! left the production line as the last of only Three Rover 75 tourers produced in Trophy Yellow. 48 hours later Longbridge closed. The last sold ordered 75 Tourer. Paid for by the Phoenix Four and handed over by John Towers to the Warwickshire Northampton Air ambulance service as a Rapid Response vehicle

23rd June 2017, 23:35	#3
Bogbrush82 I really should get out more....... BMW X3 2.0D Join Date: May 2017 Location: Tipton Posts: 2,383 Thanks: 51 Thanked 765 Times in 421 Posts	Apologies for that - I knew that they all had pumps in the rear, but for some reason my Brain lost all it's cells and I realised after I posted it that I should have asked about both pumps instead of just the rear one __________________ Current car: BMW x3 2.0d (The one with the M47 engine!) Rolled off the line on December 14th, 2004.

25th June 2017, 10:02	#4
Arctic Give to Learn Freelander 2 Join Date: Aug 2010 Location: West Midlands Posts: 18,709 Thanks: 1,155 Thanked 6,407 Times in 3,874 Posts	Hi David. From memory I think I commented that you car being an 04 plate had the under bonnet pump as well as the in tank pump, if you remember I said unplug the under bonnet pump when it is quite at home and check to see if you can hear the in tank pump working, You can check the UB pump also does it seem noisy It could also be the HPFP regulator O-rings, removal of the starter required for access to check. Do you also remember I commented on the intercooler hose being past it's best, are you getting any black smoke on acceleration, if so the hose could have a split in it. As above it could be the maf if so unplug it and see if it makes any difference. __________________ Arctic Givology Learn to Give Everything is Achievable ad altiora tendo. Check out our Nano meet dates http://www.midlandsnanomeets.co.uk/ http://www.the75andztclub.co.uk/index.php?thepage=howto " You do the work , we supply the expertise "

25th June 2017, 11:04	#5
Bogbrush82 I really should get out more....... BMW X3 2.0D Join Date: May 2017 Location: Tipton Posts: 2,383 Thanks: 51 Thanked 765 Times in 421 Posts	Thanks Arctic. Think I'll spend the day checking it out and let you know what I find. __________________ Current car: BMW x3 2.0d (The one with the M47 engine!) Rolled off the line on December 14th, 2004.

25th June 2017, 11:58	#6
Bogbrush82 I really should get out more....... BMW X3 2.0D Join Date: May 2017 Location: Tipton Posts: 2,383 Thanks: 51 Thanked 765 Times in 421 Posts	Forgot to mention - I've not noticed any black smoke, except when flooring it. Can the pipe still fail and not cause any? __________________ Current car: BMW x3 2.0d (The one with the M47 engine!) Rolled off the line on December 14th, 2004. Last edited by Bogbrush82; 25th June 2017 at 12:00..

26th June 2017, 21:16	#7
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,392 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	What can happen is that because the inter cooler pipe is 'soft' from age, when you floor it, it 'blows up'and you lose some power. __________________ Great Barr, Birmingham.

27th June 2017, 11:05	#8
Bogbrush82 I really should get out more....... BMW X3 2.0D Join Date: May 2017 Location: Tipton Posts: 2,383 Thanks: 51 Thanked 765 Times in 421 Posts	Quick update - Turbo lag almost completely gone after disconnecting the MAF, but power has gone down a fraction as a result. __________________ Current car: BMW x3 2.0d (The one with the M47 engine!) Rolled off the line on December 14th, 2004. Last edited by Bogbrush82; 27th June 2017 at 11:08..