1.2 12v Fabia, won't start

[hutchysrs50]

Got a 2003 Fabia, 82,000 on the clock, but it's a none runner... Just had a quick look at it.

No fault codes

Got fuel pressure and plenty of petrol

Got a great spark

Compression test shows...

Cylinder 1 - 180

Cylinder 2 - 190

Cylinder 3 - 155

So compression is down on 3 but 155 should still be enough to run shouldn't it?

I'm thinking the timing chain may have failed and jumped a tooth possibly?

It has full dealer service history also.

[Toxicvrs]

Dodgy valves on these ones

[Breezy_Pete]

Get it to cylinder 1 TDC. Undo the covers off the ends of the camshafts. Eyeball the slots. Should both be horizontal, in a straight line with each other if all is well chain wise.

Can find some pics later.

[hutchysrs50]

Get it to cylinder 1 TDC. Undo the covers off the ends of the camshafts. Eyeball the slots. Should both be horizontal, in a straight line with each other if all is well chain wise.

Can find some pics later.

Was my next step but it's outside and snowing heavily! I've got a bad back so limited in what I can do, might have a look tomorrow if it's any better.

Also, this won't show any failure between the bottom and top end, only if each can has moved slightly. Any timing marks to line up by eye?

Dodgy valves on these ones

It's possible on number 3 but 155 should still be enough for the car to run

[Breezy_Pete]

Was my next step but it's outside and snowing heavily! I've got a bad back so limited in what I can do, might have a look tomorrow if it's any better.

Also, this won't show any failure between the bottom and top end, only if each can has moved slightly. Any timing marks to line up by eye?

It's possible on number 3 but 155 should still be enough for the car to run

Yeah it will. If the bottom end is one tooth out relative to the top end (but the two cams are OK relative to each other) the slots on the cams will be away from horizontal when Piston No.1 is at the top of its travel, and not lined up with each other.

When I say horizontal, I mean perpendicular to the tall axis of the engine, as the whole engine sits tilted forward or back a bit, I forget which.

 

If all is well, at No1 TDC  you should see =   =

If all is not well, it'll be more like /  /  or \  \ (but not as steep angles as those)

Edited 28 January, 2015 by Wino

[hutchysrs50]

Good diagram haha thanks.

I've done many Vauxhall timing chains and others including two of these engines so understand what you mean about lining them up.

I have a timing kit but it's a pain putting the crank one in for now, just doing simple things to eliminate

[Breezy_Pete]

No.1 Sparkplug out,  long thing down the hole onto the piston crown, turn engine until it's highest, that'll get you close enough. No need to lock for this check. (Much, much easier to turn engine with all three plugs out, as I'm sure you're aware). Doesn't matter if it's TDC on compression stroke or exhaust stroke either, the cam slots are horizontal in both cases.

 

Photos in this post.

Edited 28 January, 2015 by Wino

[hutchysrs50]

Yeah, thanks.

I bought it expecting it to need a new cylinder head or at least new valves anyway, hopefully I'll get away with just a chain for now, if that's what it is of course.

[hutchysrs50]

Also noticed you said your compression was around 230psi, a lot higher than mine.

[Breezy_Pete]

Also noticed you said your compression was around 230psi, a lot higher than mine.

Was yours with cold or warm engine? Pretty sure mine was warm, which might be the difference.

[hutchysrs50]

Stone cold engine, bloody freezing in fact

[hutchysrs50]

And to clarify, if anyone knows.

Is the main fault with these the valves just getting dirty and not seating properly?

Would removing the cylinder head, cleaning all the valves and reseating them fix the problem?

[Toxicvrs]

And to clarify, if anyone knows.

Is the main fault with these the valves just getting dirty and not seating properly?

Would removing the cylinder head, cleaning all the valves and reseating them fix the problem?

fairly sure this is Taylor 93s subject

[sepulchrave]

A dead crank position sensor will prevent the engine starting, so will the immobiliser.

[hutchysrs50]

A dead crank position sensor will prevent the engine starting, so will the immobiliser.

No fault codes so I've ruled them out for now.

Immobiliser light goes out like normal.

[Breezy_Pete]

According to the self-study programme on the 3-pots it takes death of crank and cam sensors to prevent engine start. I quote:

 

-------------------------------------------------------------------

Substitute functions

Engine speed sender G28, camshaft position

sender G163

If the engine speed sender G28 fails when the

engine is running, the engine stops. It can,

however, be started again.

If the camshaft position sender G163 fails

when the engine is running, the engine

continues running and can also be re-started.

If both senders fail, the engine cuts out and

can no longer be started.

-----------------------------------------------------------

On the subject of valve issues, I've read various things but have no hands-on experience of any.  Poorly installed valve seats was one thing I saw mentioned somewhere, but that may have been an isolated incident.

Worn valve guides (particularly ex.) leading to valve stem wobble, causing mis-seating valves and subsequent hotspots/burnout/cracking seems to be more often written.

 

Doubt you'll be as lucky as to find just 'muckiness' as the cause of lower compression on pot 3, but I could be wrong.

Edited 28 January, 2015 by Wino

[sepulchrave]

Pull an injector and check for a spray pattern.

[hutchysrs50]

I just think something is stopping it from starting other than the slightly lower compression on cylinder 3. I only turned the engine over a few times and didn't touch the accelerator pedal. I think if I continued to turn the engine over and fully pressed the throttle it would raise again.

I feel with the compression results I've got it should start and run, anything over 150 is acceptable to me. It's got fuel, it's got compression and its got spark, it should run...

[sepulchrave]

I just think something is stopping it from starting other than the slightly lower compression on cylinder 3. I only turned the engine over a few times and didn't touch the accelerator pedal. I think if I continued to turn the engine over and fully pressed the throttle it would raise again.

I feel with the compression results I've got it should start and run, anything over 150 is acceptable to me. It's got fuel, it's got compression and its got spark, it should run...

 

Agreed.

 

Did the ECU handshake, if so can't you check measuring blocks for stats like ignition advance, coolant temperature, injector duration etc. while you crank it?

[hutchysrs50]

Yeah, I can check all the live data tomorrow also I guess. I'm just going on the assumption that if love data had a fault it would have logged something by now.

Tempted to tow it down the road to jump start it to or at least log a fault code.

More time needs spent on it anyway, only had a quick look over it today, just posted to see what other people think.

[hutchysrs50]

Spent another half an hour lookin over it this morning, the inlet cam is fine but the exhaust looks to be out by about 3 teeth maybe. It's definey not lined up straight anyway

[hutchysrs50]

Edited 29 January, 2015 by hutchysrs50

[Breezy_Pete]

Ah, looks like you've got a bit of a  /  \  thing going on there. :'(

[hutchysrs50]

Yeah, looks that way, happy in a way, just unsure what to do next. I bought it expecting to replace valves and do a timing chain at the same time anyway, but now I'm thinking maybe just leave the cylinder head and just replace the chain...

But then it's a worry being a common fault to wear out valves and dirt seats etc, and of course if the valves have touched the piston but I think that's unlikely.

Edited 29 January, 2015 by hutchysrs50

[sepulchrave]

No chance the valves are bent with those compression readings.