P38A Roughness Timing.

swac · Jan 14, 2022

For some of you this must seem a strange title for a thread but for those of you with a Nanocom hopefully it will not.
Anyway the truck felt a bit lumpy the other day, it's a 4.0 litre Thor engine running on LPG, so I plugged in the Nanocom and although it shows no faults, when I had a look at inputs and roughness settings cylinder 7 was showing a value sometimes as high as 3.0 whilst all other cylinders were 0.00. Any ideas anybody?

kermit_rr · Jan 14, 2022

a petrol engine doesnt successfully fire every cylinder 100% of the time. its completely normal and displayed in nanocom as roughness. i dont recall the figure but there is a predetermined count before a number of misfires are registered as an actual misfire
an occasional blip to 3 shouldnt be much of an issue, but if its consistent, then it needs to be checked out, possibly a bad plug or lead

swac · Jan 14, 2022

kermit_rr said:
a petrol engine doesnt successfully fire every cylinder 100% of the time. its completely normal and displayed in nanocom as roughness. i dont recall the figure but there is a predetermined count before a number of misfires are registered as an actual misfire
an occasional blip to 3 shouldnt be much of an issue, but if its consistent, then it needs to be checked out, possibly a bad plug or lead

Thanks Kermit, that was a quick respnse. I'll change the plug and let you know.

tomcat59alan · Jan 14, 2022

swac said:
Thanks Kermit, that was a quick respnse. I'll change the plug and let you know.

And check the lead,and it's not a truck.

it's a gentleman's carriage

swac · Jan 14, 2022

tomcat59alan said:
And check the lead,and it's not a truck. it's a gentleman's carriage

Apologies, the leads are only about 2 years old but I will check if plug change doesn't work.

kermit_rr · Jan 14, 2022

check the colour and condition of the plug, if it looks good then move to a different cylinder and see if the issue moves

tomcat59alan · Jan 14, 2022

swac said:
Apologies, the leads are only about 2 years old but I will check if plug change doesn't work.

I'm afraid age means nothing these days, accepted, I had to sack the last butler for calling the Carriage a Je*p , worse than a truck.

Rubberknees · Jan 14, 2022

tomcat59alan said:
And check the lead,and it's not a truck. it's a gentleman's carriage

Here here my good man

P38A Roughness Timing.

swac

Active Member

kermit_rr

Very

swac

Active Member

tomcat59alan

Well-Known Member

swac

Active Member

kermit_rr

Very

tomcat59alan

Well-Known Member

Rubberknees

Well-Known Member

Similar threads