eho

Recently my S throws a CEL. According to the scangauge, it is a miss-fire code in chamber 3 & 4.

Since then, I had cleaned the Spoon air filter, gave the throttlebody a good wipe, had new spark plugs installed. However it still occasionally re-throws the same error code when the car is idle and/or driving at low speed (below 10mph).

If this is relevant at all I notice that the old spark plugs have progressive carbon build up from 1 to 4. (Chamber 1 being almost no carbon build-up and chamber 4 plug end was literally brown).

Am I right in thinking the next step is a new engine loom (breakers / new from Honda) and possibly a pressure check on the cylinders?

eSeM

Mugen888 was getting this when he swapped from an OEM to Mugen ECU.

IIRC he had is valve clearances checked and reset and this fixed the problem.

veehexx

+1 for clearances.

i got cel on same cylinders - turned out to be 1 single knackered lobe on the camshaft - the theory is the same; excessive valve clearances.

ps - the mis-fire code is not exactly true. think of it more as a 'reduction in power' fault code.


i'd also try swapping the coil packs (units that go directly ontop of the spark plugs) between cyl 1&2, to 3&4 and vice versa. see if the fault code moves.

also, as another thing to try - injector cleaner. i'm sure i've heard of others with dirty injectors on these forums....

MB

Do it methodically.

It could be a lot of things causing a misfire code.

Guide in my signature will give you some clues.

U9aXy6Dn

If you're struggling to start in the mornings or it's taking more time to turn-over, it could well be a coil pack.

When my car did it's coilpack it'd also been gradually killing my red top battery which are supposedly rock-solid - and bearing in mind friends have jumped some huge cars off of it in the past i was shocked.

willf

Valve clearences are a good starting point - plugs give a very good indication as to how your engine is burning - if they are different colours, it is not burning efficiently...

Valve clearences could cause this (along with all sorts of other things), so do this first and try it!

eho

The car starts no problems even when cold.

eho

Thanks for all the inputs

What I do first is to re-arrange the coil pack, see if the code moves to the other chambers. I will run this test for 2 weeks (since it is a weekend car)

If the code don't move then it means my coil packs are okay and a valve clearence check is next.

I keep you guys posted.

MB

Coil packsa re the easy place to start.

There are also plugs and injectors to think of if the misfire codes dont move.

eho

Plugs are brand new so we can rule that out.

Where can I get hold of some injector cleaners? It is easy to do myself?