Go Back   The 75 and ZT Owners Club Forums > The 75 and ZT Owners Club Forums > Technical Help Forum
Register FAQ Image Gallery Members List Calendar Mark Forums Read
Notices

Reply
 
Thread Tools Display Modes
Old 25th April 2020, 11:11   #1
Beedge144
Newbie
 
Rover 75 Saloon

Join Date: Jun 2018
Location: Mold
Posts: 15
Thanks: 0
Thanked 2 Times in 2 Posts
Default 2.0 CDti - Won't rev past 2500 rpm, or change down gear

Hi forumites, during this lockdown I've not driven my 75 CDti much at all except for a pop to the shops, and the car has been mostly sitting on the driveway in this lovely weather, otherwise it had been driven on long commutes and distances - North Wales to Birmingham and Edinburgh without any fuss or bother.

I took her out the other day for a run this week (to Chester), but find I've lost top end power, and it won't accelerate past 2500 rpm, or change down gear/ kick down once I get her up through fourth and to 50 mph.

I've been through various other threads, and not had much success and a lot of the older threads have no photo links for me to follow.
I did disconnect the MAF sensor, but it still won't rev up, even in Neutral.

There are no engine management warning lights, no smokiness from the exhaust, everything is running smoothly at low revs, it's just refusing to "push on"
Beedge144 is offline   Reply With Quote
Old 25th April 2020, 11:13   #2
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

Check and clean the LP fuel pressure sensor plug connection - it is the one on top of the fuel filter.
Mike Noc is offline   Reply With Quote
Old 25th April 2020, 11:24   #3
Beedge144
Newbie
 
Rover 75 Saloon

Join Date: Jun 2018
Location: Mold
Posts: 15
Thanks: 0
Thanked 2 Times in 2 Posts
Default Quick Update

I've now reassembled everything, and now the ignition won't fire :-(
I'm beginning to wonder if it may be a fuel pump problem ?
Beedge144 is offline   Reply With Quote
Old 25th April 2020, 11:25   #4
Beedge144
Newbie
 
Rover 75 Saloon

Join Date: Jun 2018
Location: Mold
Posts: 15
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by Mike Noc View Post
Check and clean the LP fuel pressure sensor plug connection - it is the one on top of the fuel filter.

Thanks Mike - Just got to locate that now ;-)

Quick Google and seen that you've posted on this a fair few times :-D
Will have a look after my bacon butty

Last edited by Beedge144; 25th April 2020 at 11:33..
Beedge144 is offline   Reply With Quote
Old 25th April 2020, 11:30   #5
marinabrian
 
marinabrian's Avatar
 
MG ZT

Join Date: Jan 2011
Location: Newcastle Upon Tyne
Posts: 20,151
Thanks: 3,565
Thanked 10,837 Times in 5,718 Posts
Default

Quote:
Originally Posted by Beedge144 View Post
Thanks Mike - Just got to locate that now ;-)
It is on top of the fuel filter housing, attached to the inboard side of the battery box Bruce

Your symptoms hint at low fuel pressure, how much is in the tank, and if the answer is 1/4 or less, you need to put more fuel in before condemning the underbonnet fuel pump, located just behind the fuel filter, as there will be a possibility the in tank fuel pump is not working

Brian
marinabrian is offline   Reply With Quote
Old 25th April 2020, 11:36   #6
Beedge144
Newbie
 
Rover 75 Saloon

Join Date: Jun 2018
Location: Mold
Posts: 15
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Quote:
Originally Posted by marinabrian View Post
It is on top of the fuel filter housing, attached to the inboard side of the battery box Bruce

Your symptoms hint at low fuel pressure, how much is in the tank, and if the answer is 1/4 or less, you need to put more fuel in before condemning the underbonnet fuel pump, located just behind the fuel filter, as there will be a possibility the in tank fuel pump is not working

Brian
Half a tank - popped £20 in the other day

Usual problems I guess of running too low on diesel, seems to be a recurring theme on the forum
Beedge144 is offline   Reply With Quote
Old 25th April 2020, 11:39   #7
marinabrian
 
marinabrian's Avatar
 
MG ZT

Join Date: Jan 2011
Location: Newcastle Upon Tyne
Posts: 20,151
Thanks: 3,565
Thanked 10,837 Times in 5,718 Posts
Default

Quote:
Originally Posted by Beedge144 View Post
Half a tank - popped £20 in the other day

Usual problems I guess of running too low on diesel, seems to be a recurring theme on the forum
It sounds like the underbonnet fuel pump is at fault in that case, if there is a 12v supply between the white and purple and the black wire entering the plug on the top of the pump, another alternative is a blocked or collapsed fuel filter.

Try this, ignition on position 2 for 30 seconds, then off, repeat but at the end of the 30 seconds crank the car to see if it will start.

Brian
marinabrian is offline   Reply With Quote
Old 6th June 2020, 11:07   #8
Beedge144
Newbie
 
Rover 75 Saloon

Join Date: Jun 2018
Location: Mold
Posts: 15
Thanks: 0
Thanked 2 Times in 2 Posts
Default Belated update

Much thanks has to go out to Jules, with whom I got in touch over this issue.
As he's not too far down the coast from my abode in N Wales I was able to drop my Conny in with him to diagnose the issues.
Ironically on the day I drove down there were actually no problems with power delivery at all
Fortunately Jules has the kit to investigate these matters, the fuel pressures were coming it at approx 210 psi(?) and we replaced both the Under Bonnet and Fuel Tank pumps.
Pressure delivery is now around the 270 mark, and there have been no further issues at all

He also discovered a worn drop link, and was also able to track down the faulty wiring on the NS Headlamp
https://the75andztclub.co.uk/forum/s...d.php?t=303510
And ran in a new connection for me.

Also able to get a few other bits and bobs resolved :-)
So if you're in need of help in North Wales, Jules is definitely the man to go to
Beedge144 is offline   Reply With Quote
Old 6th June 2020, 13:53   #9
Mike Noc
This is my second home
 
Mike Noc's Avatar
 
Rover 75 CDT Manual Connoisseur SE, Rover 75 CDT Automatic Connoisseur SE & a Freelander Td4.

Join Date: Jul 2009
Location: Hampshire
Posts: 11,531
Thanks: 3,470
Thanked 3,119 Times in 2,247 Posts
Default

Good to hear you are sorted.
Mike Noc is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT. The time now is 05:11.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd