Hi all, been busy with a few things of late, so my series 3 rebuild is on hold.
 

One of the things I've been fighting with is my sisters Skoda fabia, 2004, 1.2 6v (3 cylinder) BMD

started a few months ago, starts from cold great, smooth, quiet, plenty of "power" as it warms up it gets to a point of hesitation at about 3.5k revs then if you try to push past it it feels like someone pulled a choke on. ENgine warning light on,

it was taken to our local garage, can be a bit of a douche, but does good work.
they plugged it in, came up with 

p0301 - cyl1 misfire

p0303 - cyl3 misfire

p0172 - bank 1 too rich

 

the garage traced all the vacuum lines, swapped injectors and coil packs for known good, swapped cam/crank sensors for known good. compression test came back good.

made no difference at all.

Car is now at home, it was parked up for 2 months, started it monday after replacing the coolant temp sensor (though I think this new part is dodge as it was a cheapy), as before runs lovely when cold. 

but then business as usual, and showing the same fault codes.

THe car isn't worth alot but I've never been beaten on a problem!

Any ideas? I'm a bit fed up with it now! EGR? does it have one?

 

from a read here, I'll check the vacuum line between the brake servo and wherever it goes.

 

I currently dont have vcds, just a code reader. Ill look into vcds when I get chance.

Thanks!
Ben

It's the 6V so unless it's had new valves fitted already they'll be burnt out and losing compression.

2 minutes ago, sepulchrave said:

It's the 6V so unless it's had new valves fitted already they'll be burnt out and losing compression.

 

That's interesting, I hadn't considered that, 

 

The garage did a compression test, (though not a warm engine if course,) but not a leak down test. Which came back good, I forget the numbers, but he was happy with them.

 

It's also not breathing heavy from the rocker cover, hot or cold. 

 

But I'm not familiar with these engines! 

 

Thanks! 

Ben

Don't listen to @sepulchrave

(at least not yet)

 

These are very simple engines.

 

The usual suspects are spark plugs and coils. Followed by injectors.

 

Did they put some new plugs in (around £10 for the set)?

 

Tracing vacuum lines? Theres only one, brake servo to inlet manifold. Usually split at the ends and air gets drawn so losing brake assistance and weakening fuel air mixture. As the engine rocks forward under power/braking, a split vacuum line can move back off the manifold connector.

 

Not sure what this swapping bits for good ones is about, how do they know they are good?

 

It may have an EGR valve (the AZQ and BME have) , but in my experience it doesn't affect power but would put the check engine light on with an EGR fault code.

 

Did they put a new air filter on?

 

Start with new plugs.

 

Edited 20 January, 20224 yr by xman

Thanks @xman

 

When I got it I did oil, oil filter, plugs and air filter. Ill pop the plugs out though and swap them. 

 

All I didn't change was the fuel filter, but it's on my list to do, just because it'll make me feel better! 

 

The known good were from the cars twin that was in for something else at the time. (cheeky, but he was running out of ideas too!) 

 

Indeed simple engines, one of the reasons I went for it. Having messed with a Ford tdci I was looking forward to a rest! 

 

Cheers! 

Ben

On further digging its looking as if the 6V version doesn't have EGR only 12V versions.

 

What @sepulchrave said about valves is a possibility as 6v htp are known for this.

Check the soft rubber connecting pieces in the PCV valve outlet hose. That connects through to the inlet mani so can be a big vac leak if rotted out like on this BMD in a Polo.

No EGR as xman says.

Sep could be right; borescope would probably see damaged valve edges if present.

 

Edited 20 January, 20224 yr by Wino

Evening folks, sorry for the delay in this. My mum started chemo and it's really hammering her. 

 

But... 

 

Got in the fabia today, started first turn of the key, nice and smooth sounds good. Left it to warm up for 20 mins. 

 

Got back in, revved cleanly to to 5k~ then back up Idle fine. Tried again and it started to cough at 3.5k. Then seemed to choke out. Let off the throttle, and it slowed down refused to idle. 

 

I can get it to hold a high rev "on the pedal" for maybe 10 seconds then it'll start to die. 

 

Started up again and it idled fine. Repeat as above, managed to get it to idle, very rough/misfiring, exhaust steaming like an old fowler. 

 

YouTube video below. 

https://youtu.be/2dhsyCCVNug

 

 

 

Vacuum lines from throttle body to servo are good as are the ones around the pcv valve. 

 

Cheers 

 

Ben

Evening folks, sorry for the delay in this. My mum started chemo and it's really hammering her. 

 

But... 

 

Got in the fabia today, started first turn of the key, nice and smooth sounds good. Left it to warm up for 20 mins. 

 

Got back in, revved cleanly to to 5k~ then back up Idle fine. Tried again and it started to cough at 3.5k. Then seemed to choke out. Let off the throttle, and it slowed down refused to idle. 

 

I can get it to hold a high rev "on the pedal" for maybe 10 seconds then it'll start to die. 

 

Started up again and it idled fine. Repeat as above, managed to get it to idle, very rough/misfiring, exhaust steaming like an old fowler. 

 

YouTube video below. 

https://youtu.be/2dhsyCCVNug

 

Rough idle video here

 

 

 

Vacuum lines from throttle body to servo are good as are the ones around the pcv valve. 

 

Cheers 

 

Ben

Doesn't sound like an engine with a future, in my opinion.

29 minutes ago, Pete_Ex-Wino said:

Doesn't sound like an engine with a future, in my opinion.

I'm beginning to agree, mainly because I'm running out of time and energy to deal with it. 

 

I'm currently struggling to believe that the engine is physically knackered. Its nice and smooth, starts easy, compression test came back good, no blow back or pressure in the rocker cover. Passed its emissions test, exhaust only steams when it starts to struggle. 

 

If it seems like it's going to have to be punted on or scrapped then I'll pull the head off for a look. 

 

Cheers 

Ben 

Dodgy MAF? (Assume it has one?) What's the live data say about readings from lambda sensors?

 

 

Only a leakdown test will reveal the valve damage early on in the process.