Testing for misfires
Author
Discussion

Tc24

Original Poster:

533 posts

169 months

Monday 28th October 2013
quotequote all
...using an OBD lead, laptop and little technical knowledge.

My Civic doesn't seem to be enjoying the cold weather, and is hesitating a little bit on acceleration.

There are no warning lights on the dash, and other than the slight hesitation, everything seems to be ok. It had new plugs and the valve clearances adjusted at its last service at the start of the year along with the usual oil & filters.

Bored a couple of Saturdays ago, I tried gapping the plugs (all were ok) and cleaning out the throttle body to see if there was any difference. There wasn't.

Is there any way of testing for misfires or similar gremlins using a generic OBD lead and software? If so, how? Or am I just expecting too much of a 1.6 4cyl engine in the cold?

trickywoo

14,236 posts

260 months

Monday 28th October 2013
quotequote all
How old are your HT leads or coilpacks?

Tc24

Original Poster:

533 posts

169 months

Monday 28th October 2013
quotequote all
trickywoo said:
How old are your HT leads or coilpacks?
I've not changed them in my 2 years of ownership, so would assume they've never been done. 9-10 years old if that is the case....

Krikkit

27,938 posts

211 months

Monday 28th October 2013
quotequote all
trickywoo said:
How old are your HT leads or coilpacks?
This. Hesitation in my experience is usually indicative of a weak spark - either plugs (already changed and gapped, are they the right type?), leads or coilpack. smile

Tc24

Original Poster:

533 posts

169 months

Monday 28th October 2013
quotequote all
Krikkit said:
This. Hesitation in my experience is usually indicative of a weak spark - either plugs (already changed and gapped, are they the right type?), leads or coilpack. smile
Definitely the right plugs, I'm anal about things like that hehe

Must admit, the wiring looked a bit ropey. Sprayed all terminals with contact cleaner when I had the plugs out, but as mentioned, this made no difference. They don't look like HT leads per se as I've had in other cars.

Not my engine bay, but pretty much identical. There's some rather flimsy looking wiring under the black plastic cover that I assume administers the current to the coilpacks and subsequently sparks:



What's that part called? Nothing comes up on ECP for HT leads!