MG-Rover.org Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
I have run out of ideas any suggestions as to where to look next? I have a 2005 TF Spark. I have a misfire, it starts first time every I can sit and rev it no problem, hold at constant revs no probs, After a short run it will start to misfire under load. I've changed the plugs, leads, coil packs and fuel filter. Any suggestions what to check next, I don't have a diagnostics checker so am thinking it may need a trip to the garage. Just thought I'd ask here.

Thanks in advance
 

·
Premium Member
Joined
·
605 Posts
You really do need to get a scan tool as we will only be guessing. Either that or get hold of a mobile MG mechanic. I’ve not had an mg for a few years now but I always used Russell Walsh if I couldn’t fix it. He ha# T4 which is the MGR kit. I’m sorry, but you’ve done the usual culprit’s already. Problem with forum's is that they can cost you dearly with best intentions.
 

·
Registered
MGF's x 5 MGTF's x 6, Rover 620Ti & Cortina Mk3
Joined
·
2,114 Posts
Seems like you may have an electrical issue which maybe heat related as your issue only really starts when its has run for sometime, could be a few different things, check the crankshaft position sensor cables and also the camshaft sensor cables, if cable are ok check the both sensors although if it is an heat issue the may read alright when cold.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #4 ·
You really do need to get a scan tool as we will only be guessing. Either that or get hold of a mobile MG mechanic. I’ve not had an mg for a few years now but I always used Russell Walsh if I couldn’t fix it. He ha# T4 which is the MGR kit. I’m sorry, but you’ve done the usual culprit’s already. Problem with forum's is that they can cost you dearly with best intentions.
I understand what your saying Pat but thanks for the reply
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #5 ·
Seems like you may have an electrical issue which maybe heat related as your issue only really starts when its has run for sometime, could be a few different things, check the crankshaft position sensor cables and also the camshaft sensor cables, if cable are ok check the both sensors although if it is an heat issue the may read alright when cold.
Thanks for the reply Dert
 

·
Registered
Joined
·
1,349 Posts
It could be 101 things and you could end up spending a fortune on new sensors et al and get nowhere.

Psscan is a good start for an amateur mechanic but if you are not that way inclined, you need to go to a garage with Testbook or Pscan to get a proper diagnosis or atleast eliminate things that are not causing the problem.
 

·
Registered
MGF's x 5 MGTF's x 6, Rover 620Ti & Cortina Mk3
Joined
·
2,114 Posts
Roughly where are you in the UK Tom832?

IPsscan is a good start for an amateur mechanic
A good few members of this forum have a Pscan and may be willing to help you diagnose the fault..some would even do it for free if close to them
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #8 ·
Roughly where are you in the UK Tom832?



A good few members of this forum have a Pscan and may be willing to help you diagnose the fault..some would even do it for free if close to them
Roughly where are you in the UK Tom832?



A good few members of this forum have a Pscan and may be willing to help you diagnose the fault..some would even do it for free if close to them
Hi dert, I live in Bourn Lincs just north of Peterborough
 

·
Registered
MGF's x 5 MGTF's x 6, Rover 620Ti & Cortina Mk3
Joined
·
2,114 Posts
A tad too far away form me at todays petrol prices (South Wales) :(
 

·
Registered
mg_tf
Joined
·
600 Posts
’After a short run it will start to misfire…’ Does it misfire when stationary and warmed up, and revved rather than taken for run ( when it gets up to temperature )? If so, coolant temperature sensor might just be a suspect.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #11 ·
’After a short run it will start to misfire…’ Does it misfire when stationary and warmed up, and revved rather than taken for run ( when it gets up to temperature )? If so, coolant temperature sensor might just be a suspect.
OMG yes would cost more than the car is worth :)
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #12 ·
’After a short run it will start to misfire…’ Does it misfire when stationary and warmed up, and revved rather than taken for run ( when it gets up to temperature )? If so, coolant temperature sensor might just be a suspect.
Hi Austin, I can start and run it, rev it all ok, if I stop for a short while it will start and rev ok but under load starts missing under load, at a constant throttle it seems ok. I have checked the fans work but not checked as i dont know when the engine fan comes on
 

·
In the Garage
MG TF
Joined
·
33,654 Posts
Not sure if you have done a throttle position sensor reset yet, if not it is worth a go given that it is free however I think Austin could be right about the ECU coolant sensor.

 

·
Registered
mg_tf
Joined
·
600 Posts
Hello Tom,
Thanks for the reply, but I’m still not any clearer if this car is behaving differently when it’s fully up to operating temperature ( the critical part of the question) compared with when it’s not.
Kind regards,
Austin.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #15 ·
Hi Austin sorry,
It starts fine, I can rev it no problem, drive it temp gauge normal oil temp ok, if I stop for a short time it will start fine rev ok but when I get going it will start to misfire when accelerating, One thing I did notice I have never heard the fan in the engine compartment run, I have tested both fans so know they work. Do you think this could be the problem, even though the misfire feels like a fuel problem more than electrical. it that makes sense.

Cheers Tom
 

·
Registered
mg_tf
Joined
·
600 Posts
Thanks Tom,
So if you drive it up to temperature and don’t switch off - it will continue to run as far as you want to go without any problem - Yes?
It only gives a problem when you have driven it up to temperature and stop and restart - Yes?
Engine bay fan - Never had ours come on during our four year ownership.
Kind regards,
Austin.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #17 ·
Thanks Tom,
So if you drive it up to temperature and don’t switch off - it will continue to run as far as you want to go without any problem - Yes?
It only gives a problem when you have driven it up to temperature and stop and restart - Yes?
Engine bay fan - Never had ours come on during our four year ownership.
Kind regards,
Austin.
Hi Austin
Thanks Tom,
So if you drive it up to temperature and don’t switch off - it will continue to run as far as you want to go without any problem - Yes?
It only gives a problem when you have driven it up to temperature and stop and restart - Yes?
Engine bay fan - Never had ours come on during our four year ownership.
Kind regards,
Austin.
As far as I know that's right, its just the twice its done it I lipped it home again. I'm going to buy a cheap scanner to see if I can find the fault codes, I probably be beck when I find out what the codes are lol. Thanks very much for your help.
Tom
 

·
Registered
2002 MG TF VE51FTF
Joined
·
290 Posts
Tom832 I'm not far from you (Holbeach) and I have pscan, the only problem is so far I've only connected it up once to have a look and all the readings are there but as yet I have no idea what the parameters are for each one. I keep looking for a list or something that shows values (+/-) to give some idea of where problems lie, it's something I want to learn but things like cambelts keep taking my time up.
I could if you wanted run over to you and compare results from the 2 cars to see what's different and perhaps we will both learn something.
 
1 - 19 of 19 Posts
Top