The 75 and ZT Owners Club Forums

The 75 and ZT Owners Club Forums (https://www.the75andztclub.co.uk/forum/index.php)
-   Technical Help Forum (https://www.the75andztclub.co.uk/forum/forumdisplay.php?f=11)
-   -   Lumpy engine/misfiring (https://www.the75andztclub.co.uk/forum/showthread.php?t=325918)

freelancer 17th October 2023 13:23

Lumpy engine/misfiring
 
Anyone in Perth/Dundee area with a T4 diagnostic available tomorrow?
On a visit to daughter and family near Auchterarder today but lumpy engine as if not firing on all cylinders on way down from Aberdeen this morning. Suspect maybe a coil pack or spark plug „gone“ (or Vis motor issue?) but obvs. not sure.
Thankfully no engine light warning.
Have pm‘d Astraeus but not sure if he is around.
Tks

freelancer 24th October 2023 19:10

Postscript to my earlier message:

OK so there were no T4 patrolman standing by on the road back home last Wednesday...

Before I do have the chance to have it T4 checked, I thought I would describe symptoms a bit more fully in case its a bit more obvious to those of experience or with advice to offer.

Limped home as journey down had been with possibly slight misfiring? and slight vibration and then with slight misfiring and very noticeable vibration, above say 55mph. Improved when coasting or clutch engaged. Problem has not gone away. No engine warning lights(s) showing at any time.

Took car to Halfrauds early on Saturday morning as I know one of the guys slightly, so yes they plugged in their diagnostic tool ...but said there were no faults showing. Mmmm not sure how confident I am of that...

:shrug:Do you think it is engine; spark plug(s), ignition pck(s) or VIS motor
or a tyre, wheel, bearing, half-shaft issue? :shrug:

The car was MOT'd three weeks ago but garage cannot take vehicle in to have a look at it for another 10 days.

Any advice gratefully received thanks

SD1too 24th October 2023 19:47

Quote:

Originally Posted by freelancer (Post 2981451)
Do you think it is engine; spark plug(s), ignition pck(s) or VIS motor
or a tyre, wheel, bearing, half-shaft issue?

Hello Ian,

Misfiring, ranging from just detectable to so severe that the engine was reluctant to run from a cold start, was the symptom when I had ignition coil faults. I've never had sparking plug trouble in nineteen years of ownership. VIS actuator troubles don't cause misfiring.

It won't be a drivetrain issue. If I were you Ian, I would invest in a T4 diagnosis. When I had ignition coil faults, the "check engine" light remained off but T4 was able to identify which cylinder was responsible which was incredibly useful!

Simon

Lagetha 26th October 2023 12:57

Toaf?
 
1 Attachment(s)
Is there anyone near you with TOAF, I use it on my 1.8 which runs fine, and has no warning lights - but TOAF reports minor problems... as per attached text file.

freelancer 27th October 2023 16:45

:target: Update:
Won't get a chance for T4 until week after next ...but meanwhile have got hold of a Foxwell NT204 OBDII Reader (from the very helpful. informative guys at Gendan).
I've got a fault code P1035.
Lots of suggestions when I resort to Google but failure in ignition coil No.? is there.
Might that be it?

suzublu 27th October 2023 17:16

Quote:

Originally Posted by freelancer (Post 2981662)
:target: Update:
Won't get a chance for T4 until week after next ...but meanwhile have got hold of a Foxwell NT204 OBDII Reader (from the very helpful. informative guys at Gendan).
I've got a fault code P1035.
Lots of suggestions when I resort to Google but failure in ignition coil No.? is there.
Might that be it?

For your info :cool: https://www.the75andztclub.co.uk/for...ad.php?t=42209

SD1too 27th October 2023 17:47

Quote:

Originally Posted by freelancer (Post 2981662)
I've got a fault code P1035.

That code doesn't exist for the Siemens 2000 Ian (source: RAVE). This is the problem with using third party code readers.
Get it on the T4 in a couple of weeks and let us know what it says please.

Cheers,

Simon

freelancer 5th November 2023 16:30

UPDATE:

Had T4 tested yesterday. Code P0303. Cylinder 3 misfire.
Removed coil and plug: plug in good condition and correct gap; put in new replacement coil.
Took car for 5 minute run, (country roads only), to put engine under load, seemed fine. Re-tested on T4, no re-occurrence of fault code P0303. Sorted(?).

Took car late yesterday afternoon on A90 dual carriageway. Repeat, as before, of significant vibration above around 55-60 mph as described and discussed earlier on this threads. :eek:

I'm now thinking on the second part of my 2nd entry on this thread:

Do you think it is engine; spark plug(s), ignition pack(s) or VIS motor
or a tyre, wheel, bearing, half-shaft issue?

even though it was answered: "It won't be a drivetrain issue".


Might it well be a drivetrain issue.?

First stop now I think is to have a wheel alignment check.

roverbarmy 5th November 2023 22:06

If your model has coil leads (prior to 2002), they are known to break down (carbon break up) and also the connection (lead to plug) can deteriorate/break up. A new set of leads cured the same problem on mine.:shrug:
Matt will have them? Cylinder 3 is middle one behind the grill (ie not at the back of the engine)

SD1too 6th November 2023 07:02

Quote:

Originally Posted by freelancer (Post 2982360)
... even though it was answered: "It won't be a drivetrain issue".
Might it well be a drivetrain issue.?

Hi Ian,

That answer of mine was in response to your report of engine misfiring which can produce vibration. The priority was therefore to deal with the engine fault which you have now done with a new ignition coil on cylinder no. 3.

You're now reporting significant vibration at a particular speed but no engine misfiring so I agree that mechanical faults now need to be investigated. I'd suggest that you begin with wheel balancing if you're experiencing vibration through the steering wheel. A four wheel alignment check is always a good idea if it's never been done (common symptoms are uneven tyre wear and poor handling but in my experience, not vibration).

Simon


All times are GMT. The time now is 10:49.

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