Diagnose my car fau...
 

  You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more

[Closed] Diagnose my car fault

12 Posts
10 Users
0 Reactions
81 Views
Posts: 4439
Full Member
Topic starter
 

So the next fun and games I had this weekend was with the wifes car. I drove it to gizburn and while on the motorway or driving uphill in 5th or 6th at approximately 2.5k rpm I can make the car misfire by planting the throttle. Below 2k and above 3k it doesn’t do it. I managed to get it to throw an EPC fault which said misfire on cy1 and 4 but this has now gone after switching the car off and on again.

It’s a 1.4tsi golf on 40k. Im thinking of swapping out the plugs before the coils and seeing If that does anything. Any other suggestions?


 
Posted : 11/09/2017 2:34 pm
Posts: 251
Full Member
 

[i]Any other suggestions? [/i]

Get it plugged in to some proper diagnostic equipment.


 
Posted : 11/09/2017 2:38 pm
Posts: 17273
Free Member
 

Water damage from the neighbours house?


 
Posted : 11/09/2017 2:41 pm
Posts: 4439
Full Member
Topic starter
 

possibly panther, think i could claim of them.... oh wait....


 
Posted : 11/09/2017 3:06 pm
Posts: 3879
Full Member
 

I had a misfire on a 1.8 K-series Rover 75 - would only misfire under load at certain RPM's. Tried all sorts. Turned out to be a single wire in one of the looms running to the coil packs. Was not/could not be picked up by diagnostics.


 
Posted : 11/09/2017 3:08 pm
Posts: 19914
Free Member
 

Coil pack.


 
Posted : 11/09/2017 3:34 pm
Posts: 39449
Free Member
 

1.4 tsi notorious for throwing coil pack faults.

usually resolved with a firmware update.


 
Posted : 11/09/2017 3:35 pm
Posts: 4439
Full Member
Topic starter
 

Ok off to VW today. However last night i replaced the plugs. Noticed that the ones going in had a 31tho gap and the ones taken out had a 41.4tho gap.

Think this would cause the misfire? Its defiantly better today.


 
Posted : 15/09/2017 9:14 am
Posts: 39449
Free Member
 

excessive gap will cause misfire

Torque : 25Nm
Plug gap 0.8mm to 0.9mm (31.5 thou - 35.5 thou)
Change interval : 60,000Km (37,000miles)

so it seems to tally up.


 
Posted : 15/09/2017 10:00 am
Posts: 9
Free Member
 

Plugs first and then coil pack.
Mum's 1.6 focus had this once. I checked the plugs and the gap was massive. Regapped as a temp fix and then replaced them (they'd done 72k 😯 ). Made a massive improvement, but there was still a hesitation. Replaced the coil pack and all good.


 
Posted : 15/09/2017 10:14 am
Posts: 0
Free Member
 

Had a misfire.

OBD2 live running showed 2 weak cylinders.

Swapped plugs with good cylinders. No change.

Swapped coils with good cylinders and misfire cured but moved to the healthy cylinders and coil pack codes.


 
Posted : 15/09/2017 2:51 pm
Posts: 0
Free Member
 

Coil packs sound likely.

I'd treat 'proper diagnostic equipment' with a pinch of salt unless it was being interpreted by someone that actually understands engines and injection and ignition systems. I've seen too many cases where the computer misidentified and the owner was essentially fleeced for a 'replace whatever computer says' until the fault was finally fixed by accident (or by a different mechanic/garage).


 
Posted : 15/09/2017 2:56 pm
 muzz
Posts: 160
Free Member
 

Undoubtedly coil pack


 
Posted : 15/09/2017 4:57 pm

6 DAYS LEFT
We are currently at 95% of our target!