Hi, my son experienced a miss fire today the car would only go under 3k revs, the same thing happened  a while back and the garage changed a spark plug which fixed the problem so assuming that I told him to get 3 plugs, whilst changing the plugs pulling the ignition plugs off resulted in them literally falling apart so off the the car shop we purchased 3 electronic ignition modules,  we started the car up and new that this wasn't the problem, I plugged in delphi scanner and seen the crankshaft sensor code, we purchased one and fitted but still the same, it was a rush but all parts were needed anyway, I'm thinking now it could be the harness to the crankshaft sensor, would anyone  know how I can test this ?

Sorry about the long winded post.

Skoda fabia mk1 2006 1.2

Is this the 54 bhp, single cam version of 1.2 HTP?

If so I would always recommend a compression test if misfires occur despite new plugs and coilpacks.

 

What fault code number is the crankshaft code?

Hi not sure if I'm honest, the code is 16725

 

Could it be possibly wiring, only done an oil change on it last week,its been fine then started misfiring this morning 

That code is for camshaft, not crankshaft sensor problem.  I guess that's what you actually changed? On top of rocker cover, rather than down the back of engine block?

 

Yes, wiring fault is very possible. 

 

On the back of the car, where it says HTP, are all the letters black? If so that's the single cam engine. Twin cam HTPs have a red P.

 

Sorry,it is the camshaft top of engine,it is a 1.2htp,I've asked him what colour the letters are so will add that ASAP.

 

Thanks so much

Pretty sure it's the single cam thinking about it

Timing chain jumps are also possible on the HTP engines, both types.

Can result in cam sensor fault codes, not sure about misfires.

 

If it is still misfiring, there ought to be a fault code for that too? Maybe just running very badly rather than misfiring as such?

That might point toward chain jump too.

Oh dear,so maybe it's the timing, is there a way to easily check this ?

 

Hey, I've been mulling about this all night, is there a way to test the wiring harness from the camshaft sensor , think this is the easier  of the issues to look at first if it helps reg is AV06 SXW

I'm away from resources for a few hours, but off the top of my head, I'd expect the 3 wires at the cam sensor connector to be Earth, +5V and signal output.

The 5V will only be present with ignition switched on, possibly ony with engine running, try both.

Earths are typically brown or brown with another trace colour.

Tell us what colours you have at the connector.

Not sure what you'll measure on the signal output wire, but verifying the 5V and earth is a good start.

 

Maybe look for YouTube videos or Google results for checking chain timing on the 6-valve HTP engines too.

 

Thanks Pete, just confirmed it's a red p 

Oh, in that case I do know how to check the chain timing, but just visiting someone so won't be able to do much for an hour or two. I've posted the relevant photos several times so searching the mk1 Fabia forum may get you there.

 

My first thread about it needs the pics rescuing cos photobucket stole them, but this one will probably give you enough idea:

https://www.briskoda.net/forums/topic/507743-low-power-sluggish/#comment-5701026

 

Appreciate  that pete, don't rush I'm out for a few hours 2, 

There isn't 2 camshaft sensors are there ?

No, just one that looks at intake cam.

Link in my previous post shows enough about checking timing, I hope, though you might need to read a bit as well as look at the pics.

You don't need timing tools to check, just eyeballs.