Richard Bourton

Focus MK3.5 ST Diesel misfire

Recommended Posts

My focus ST diesel (2015, 40k miles) has developed an intermittent misfire over the last few months which finally threw up a P062D code. The car has been to a diesel specialist to have the injectors checked and the tests came back fine. The garage advised taking the car to a ford dealership so I proceeded to get it booked into Hartwell, Abingdon. I told them the code on arrival along with symptoms (intermittent cold misfires & occasional rough idle). They have had the car for 2 weeks now, tested the injectors 3 times and every test has come back fine but the code is still appearing and the misfire is still there. They have contacted me today saying they are going to quote to change all 4 injectors??? Surely this does not sound right? 

Share this post


Link to post
Share on other sites
My focus ST diesel (2015, 40k miles) has developed an intermittent misfire over the last few months which finally threw up a P062D code. The car has been to a diesel specialist to have the injectors checked and the tests came back fine. The garage advised taking the car to a ford dealership so I proceeded to get it booked into Hartwell, Abingdon. I told them the code on arrival along with symptoms (intermittent cold misfires & occasional rough idle). They have had the car for 2 weeks now, tested the injectors 3 times and every test has come back fine but the code is still appearing and the misfire is still there. They have contacted me today saying they are going to quote to change all 4 injectors??? Surely this does not sound right? 
Sounds like they need to check, using cylinder pressure sensing, which injector is faulting, and if they can't fix it to one cylinder, then look to other components, like the ecu or maybe loom, I. E intermittent failure to fire the injector, rather than the injector itself. Have they ruled out ecu or loom? You'd probably need to scope the different injectors to see if there was signal dropout.

Sent from my SM-G950F using Tapatalk

Share this post


Link to post
Share on other sites
10 hours ago, Abbadon said:

Sounds like they need to check, using cylinder pressure sensing, which injector is faulting, and if they can't fix it to one cylinder, then look to other components, like the ecu or maybe loom, I. E intermittent failure to fire the injector, rather than the injector itself. Have they ruled out ecu or loom? You'd probably need to scope the different injectors to see if there was signal dropout.

Sent from my SM-G950F using Tapatalk
 

The injectors have all been scoped, leak back tested TWICE and all tests come back fine. I keep asking it they’ve checked the loom or PCM but they don’t want to listen

Share this post


Link to post
Share on other sites
The injectors have all been scoped, leak back tested TWICE and all tests come back fine. I keep asking it they’ve checked the loom or PCM but they don’t want to listen
Well seems like they are not doing enough diagnostics before throwing very expensive parts at it!

Have they scoped for rail pressure in case there is behaviour not being flagged by ecu but may indicate a pressure drop at injector opening?

This reminds me of a loom issue that plagued my buddies Mi16 engine transplant in his old 205 gti; kept cutting at 3k rpm, replaced all sorts, ended up being a broken pin to wire joint in a multiplug...

Sent from my SM-G950F using Tapatalk

Share this post


Link to post
Share on other sites

Any further progress?

Sent from my SM-G950F using Tapatalk

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.