Rough idle...? - MG-Rover.org Forums
 6Likes
Reply
 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 32 (permalink) Old 25-12-2016, 18:18 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Rough idle...?

Hello and Merry Christmas everyone! After trawling the internet I'd like to get some further advice from you guys here before I go replacing every part in the car!

So, after having my flexi pipe changed due to it making the car sound like a proper chav car I've had a real rough idle.... Particularly on a cold start. However, it has happened the odd time when the car is warm and stationary at the lights. I'll try my best to explain... Of a morning, when the car first starts it feels fine and the revs are where they should be. However after about 10 seconds the revs start to drop and the car rumbles and vibrates like it's getting ready to stall. It almost feels as if the cold start up cycle gets cut short? However this wouldn't explain why it would happen when warm. When I try and drive the car when it is exhibiting these symptoms it feels like it's running on 2 cylinders and when I take it out of gear and pop it into neutral it will stall. It drives absolutely fine 90% of the time although... I feel it is the idling that screws it up. A few days ago I replaced the plugs, leads, air filter and coil packs and while it seems to run better, the fundamental problem remains. There was no evidence of oil being on the old plugs so I don't think it is the inlet manifold gasket. I'm thinking to replace the IAVC valve or at least give it a clean? Maybe fuel filter? I must say... since this has started after the flexi pipe change, could it be the o2 sensor? The garage very honestly informed me my old o2 sensor was intact and it didn't require a change so they just used the old one. I went back to them explaining my symptoms but they were adamant the sensor wouldn't cause this problem but I disagree as this problem has only arisen since the change. Any thoughts guys?? Is an o2 sensor something I can change comfortable at home you reckon??

Many thanks!!

Mem
MrKitty is offline  
Sponsored Links
Advertisement
 
post #2 of 32 (permalink) Old 25-12-2016, 18:28
Registered User
 
Join Date: Jul 2007
Car: Crystal White (Pearl) LE500 #133. Previously; TF160; F
Posts: 503
maybe a TPS reset might help? throttle position sensor I believe. a quick search of the forum should turn up the procedure. certainly worth a shot
roobs is offline  
post #3 of 32 (permalink) Old 25-12-2016, 18:35 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Thanks for the reply roobs, I'll take it for a quick spin to make him warm and give it a go.. Certainly can't hurt! Would love an easy fix such as this but when is life this simple aye??
MrKitty is offline  
 
post #4 of 32 (permalink) Old 25-12-2016, 18:36
Supporter
 
sundanceuk's Avatar
 
Join Date: Sep 2015
Location: Staffs
Car: MG TF 160
Posts: 458
TPS is a easy and free first thing to do, but I am thinking that maybe when the downpipe was changed, possibly the lambda sensor, or wiring may have been damaged. This would explain why the engine is misbehaving since you replaced the downpipe. It would be where I would be looking first. second would be the Idle air control valve.
I did have a similar fault on my car, but it disappeared after a day and has not come back, although I have serviced the engine and replaced the plugs since.
I also picked up a spare IACV from our sponsor the other day, just in case as they can act up when dirty.
Get a plug in diagnosis, it may help to narrow it down a bit!


Sundance
sundanceuk is offline  
post #5 of 32 (permalink) Old 25-12-2016, 18:40 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Cheers for your speedy replies guys, particularly on xmas day! I will get cracking, try and be a little less cynical and hope the TPS reset works
MrKitty is offline  
post #6 of 32 (permalink) Old 25-12-2016, 18:55
Registered User
 
Join Date: Jul 2007
Car: Crystal White (Pearl) LE500 #133. Previously; TF160; F
Posts: 503
you never know. sometimes you can spend hours trying to figure something out and it turns out it was something simple all along, other times not so much lol. fingers crossed it's just a glitch and not a gremlin.
roobs is offline  
post #7 of 32 (permalink) Old 25-12-2016, 18:56
Registered User
 
Join Date: Jul 2007
Car: Crystal White (Pearl) LE500 #133. Previously; TF160; F
Posts: 503
Quote:
Originally Posted by MrKitty View Post
Thanks for the reply roobs, I'll take it for a quick spin to make him warm and give it a go.. Certainly can't hurt! Would love an easy fix such as this but when is life this simple aye??
also, I love that your car is a boy
roobs is offline  
post #8 of 32 (permalink) Old 25-12-2016, 20:11 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
So I just took him out and got him nice and hot (lol), did a tps reset and it really does feel better and idle beautifully however I can't be fully sure until I start him in the morning from cold... I shall update then!
roobs likes this.
MrKitty is offline  
post #9 of 32 (permalink) Old 27-12-2016, 18:18 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Unfortunately after a tps reset I've not had much luck. Yesterday I changed the fuel filter (such a b*tch to loosen that thing) and removed the IVAC valve and gave it a good spray of carbon cleaner but to no avail... also tps reset after cleaning valve... it has to be this o2 sensor because I'm pretty stumbed!!

Last edited by MrKitty; 27-12-2016 at 19:28.
MrKitty is offline  
post #10 of 32 (permalink) Old 27-12-2016, 19:18
Stuck in the 80's...
 
IanMc's Avatar
 
Join Date: Jun 2009
Location: Braintree, Essex
Car: Flame Red '95 MGF, 17 Mini Cooper S, 13 VX Astra, 15 VX Corsa & 59 Fiesta.
Posts: 4,592
Perhaps the sensor wires are damaged?

---------------------------------------------------------------------------------------------------------------------------------------------


For .org forum only search results in Google, add "site:mg-rover.org" after your search criteria

Treat others as you would like to be treated yourself.
IanMc is offline  
post #11 of 32 (permalink) Old 27-12-2016, 19:27 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Sensor wires related to the o2 sensor Ian?
MrKitty is offline  
post #12 of 32 (permalink) Old 27-12-2016, 19:47
Stuck in the 80's...
 
IanMc's Avatar
 
Join Date: Jun 2009
Location: Braintree, Essex
Car: Flame Red '95 MGF, 17 Mini Cooper S, 13 VX Astra, 15 VX Corsa & 59 Fiesta.
Posts: 4,592
Quote:
Originally Posted by MrKitty View Post
Sensor wires related to the o2 sensor Ian?
Yes Sir - take a close look at them for damage to the insulation.

---------------------------------------------------------------------------------------------------------------------------------------------


For .org forum only search results in Google, add "site:mg-rover.org" after your search criteria

Treat others as you would like to be treated yourself.
IanMc is offline  
post #13 of 32 (permalink) Old 27-12-2016, 20:23 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Alright I'll check em out!
MrKitty is offline  
post #14 of 32 (permalink) Old 27-12-2016, 21:19
Registered User
 
Join Date: Apr 2004
Car: MGZS180,MGZR160,MGF VVC,MG Maestro T16, Rover 111
Posts: 5,740
Silly question time.

1) Is this on a TF as in your avatar info or another car, this isn't mentioned anywhere in the thread?

2) Have you scanned the ECU for fault codes?

3) Have you read OBD data at any point?
For instance what is the CTS doing?
What about fuel temp?
Is it switching to closed loop at all?
Talkingcars is offline  
post #15 of 32 (permalink) Old 27-12-2016, 23:28 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Hi talking cars, sorry I should have made that clear, it's an mg tf 135 03 plate sprint. Certainly not silly questions because I have no idea what the OBD data is :o and I have not had the ecu read, is that something I could do myself or would I need funky equipment? And the CTS is a good point, would explain why it feels to switch from a cold cycle to a warm too early!!
MrKitty is offline  
post #16 of 32 (permalink) Old 28-12-2016, 08:57
Registered User
 
Join Date: Apr 2004
Car: MGZS180,MGZR160,MGF VVC,MG Maestro T16, Rover 111
Posts: 5,740
OBD is on board diagnostics, the TF complies to OBD2 requirements. These can be read and cleared with a cheap ebay Bluetooth reader.

OBD2 fault codes are held in the ECU.

The K series has 2 CTS, one feeds the dash gauge, the other feeds the ECU and this data is used to control fueling and ignition timing.
Talkingcars is offline  
post #17 of 32 (permalink) Old 28-12-2016, 09:04
Stuck in the 80's...
 
IanMc's Avatar
 
Join Date: Jun 2009
Location: Braintree, Essex
Car: Flame Red '95 MGF, 17 Mini Cooper S, 13 VX Astra, 15 VX Corsa & 59 Fiesta.
Posts: 4,592
MrKitty, where in Essex are you?

If you were close to Braintree you could come to my place and I would gladly plug my diagnostic kit into your car and scan for error codes.

---------------------------------------------------------------------------------------------------------------------------------------------


For .org forum only search results in Google, add "site:mg-rover.org" after your search criteria

Treat others as you would like to be treated yourself.
IanMc is offline  
post #18 of 32 (permalink) Old 28-12-2016, 09:32 Thread Starter
Supporter
 
Join Date: Dec 2013
Location: Essex
Car: MG TF
Posts: 30
Ah ok that makes sense, I remember when I got him remapped he plugging it in from under the steering wheel! And Ian that would be wonderful! I live in Loughton but would be more than happy to pop to Braintree. Pm me a time and place and I'll be there
MrKitty is offline  
post #19 of 32 (permalink) Old 28-12-2016, 10:33
Stuck in the 80's...
 
IanMc's Avatar
 
Join Date: Jun 2009
Location: Braintree, Essex
Car: Flame Red '95 MGF, 17 Mini Cooper S, 13 VX Astra, 15 VX Corsa & 59 Fiesta.
Posts: 4,592
Quote:
Originally Posted by MrKitty View Post
pm me a time and place and I'll be there
You have PM Sir

---------------------------------------------------------------------------------------------------------------------------------------------


For .org forum only search results in Google, add "site:mg-rover.org" after your search criteria

Treat others as you would like to be treated yourself.
IanMc is offline  
post #20 of 32 (permalink) Old 28-12-2016, 16:54
Registered User
 
Join Date: Dec 2012
Location: Lanark
Car: MGF 1.8 VVC
Posts: 1,444
Is there a chance that the insulation sleeve on the o2 sensor wires was omitted when the sensor was swapped over?
(On my car it's a simple asbestos tube covering the bare wires)
On a hot pipe, the wires could melt causing a short.
IanMc likes this.
scot748 is offline  
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the MG-Rover.org Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Similar Threads
Thread Thread Starter Forum Replies Last Post
Sudden onset random rough idle/ rough running issues onepostwonder Diesel Forum! 2 01-03-2016 13:28
Rough Idle 1.4 zr BrokenSpring MG ZR / Rover 25, 200 & Streetwise 5 23-07-2015 12:18
Interesting idle issue: Low/rough idle when braking out of gear. Very confusing! DMGRS MG ZT / Rover 75 (Sponsored by Rimmer Bros) 13 24-09-2011 00:54
Rough Idle Dom1269 MG ZR / Rover 25, 200 & Streetwise 4 13-05-2009 21:35
rough idle amsokol MG ZT / Rover 75 (Sponsored by Rimmer Bros) 7 29-09-2008 20:00

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome