Well, its not the MAF I guess... WTF? Techies?

[devonutopia]

Hi - changed the complete top of my airbox / MAF assembly tonight, and the car is still losing power after just a couple of minutes of starting up! Now I'm running with a working MAF too! GRRRR!

What the hell else could this problem with irregular/no boost be? The last time I had something "similar" it was time for a new turbo! :( I damn well hope its not this again, because the symptoms aren't quite the same really. When the power disappears, and my foots on the floor there seems to be an extra "hiss" from under the bonnet - like the turbo when it spins up, except perhaps its not! So, what could this be? I can see myself having to pay another

[ScoobyChris]

Jason, may sound obvious, but before you shell out 30 quid, you made sure all the hoses are on tightly and that none of them have split?

Chris

[devonutopia]

hoses on the MAF? There was another hose which was attached to the MAF/airbox - behind the box, not part of the electrical - I'll check this is OK but it went off and back on the airbox OK, and securely.

What other hoses are there? I'll have to have a good rummage around, but I don't see why there should be power when I first start the car, I get full 154bhp for about 2 or 3 minutes, then something kills all power - gotta be a sensor of some sort - only thing that could just switch off the power like that - killing the ignition and restarting the car brings back the power... for a very short length of time!

Is there a "turbo" sensor as such, because this was replaced on my last car too - and if I can find it I may swap that too!

[ScoobyChris]

Was thinking more of hoses to and from intercooler and around the turbo - things which could be affecting boost. From what you described, it sounds a bit too intermittent to be anything like that............ maybe a VAG-COM session will point you in the right direction

Chris

[devonutopia]

Hi - got a new symptom that became apparent as I tractored into work today, slow as always!

Basically in all gears, at around 2000RPM, the engine will suddenly make a noise similar to that of a diesel at start-up (which sounds quite nasty when its running quiet normally) It sounds like its struggling to turn over, or overfuelling, because this sudden tractorish noise is followed by mega amounts of black smoke out the back! :( This noise only lasts about one second, but it might give a clue - seems the fuelling is all to ****! Is there another sensor that could cause this?

[fen_l&k]

Jason,

Double check all of the electrical connections too. If you were getting an intermittent connection on, say, the MAF sensor wire, you could get a similar problem to a dodgy MAF.

It sounds like a load of fuel was dumped into the engine - hence the smoke. If all else fails, get it to a dealer, Jason - I know its 30 quid, but could turn out a *lot* more expensive.

Cheers,

[devonutopia]

Howard - I'd be suspicious of this if it wasn't intermittent. There's always boost on startup - then it just dies and all these overfuelling symptoms occur... :( Gonna find a garage with vag com today.

[Chavyboy]

J, are you sure the MAF you bought hasn't been damaged in the post ?

[Dougal]

Are the cambelt, tensioner & waterpump OK?

Just a thought

[devonutopia]

cambelt etc should be fine, as the car drives really well, as it should, when first started up. And I am using the original MAF out of my wrecked Fabia, so should be fine. Is there something that needs resetting when swapping MAFs? I didn't think so. I'm gonna have to go to my dealer today I think - A local private VW/Audi place wanted

[devonutopia]

Booked into my dealers for 16.15 today, so hope their VAG COM will throw up whats wrong with my car.

Never known a turbo diesel to overfuel like mine has been, along with the lack of boost - hopefully its nothing worse than a new turbo sensor.

[fen_l&k]

Jason,

I'm not sure a turbo-related sensor would cause overfuelling like you described. The turbo comes in much lower that the 2k rpm you described. I keep wandering back to something in the area of the MAF......

... but then again, I'm no techie!!!

[devonutopia]

Cheers H.

Whats the chance of two faulty MAFs - The MAF from my wreck was stored, opened, but protected from rain etc (was inside the shell) Could this have damaged it? When the new one arrives, I'll try fitting that one as well, but my money still lies elsewhere!

[ScoobyChris]

Cheers H.

Whats the chance of two faulty MAFs - The MAF from my wreck was stored' date=' opened, but protected from rain etc (was inside the shell) Could this have damaged it? When the new one arrives, I'll try fitting that one as well, but my money still lies elsewhere![/quote']

I guess it depends how much shock it suffered when it was inverted

Chris

[devonutopia]

I guess it depends how much shock it suffered when it was inverted

[DGW]

Jason, how soon did the symptoms start after fitting the 'crashed' MAF?

[devonutopia]

Jason, how soon did the symptoms start after fitting the 'crashed' MAF?

The same as with the old MAF too - full power for around 2 minutes, then it all goes pete tong and I'm left with with slowest Skoda in the country... after the one sat on blocks at mate's place! :(

We'll see what the dealer has to say at 4.30.

[devonutopia]

Well.... It would appear the MAF from my wreck is also under-performing, so I guess it is partially to blame for lack of boost BUT it is also the case that the temperature sensor is being "sporadic" too... Cheap to replace, but a the moment the car seems to think it's sometimes a lot colder than it really is, so the auto choke is kicking in and overfuelling the engine! :( Booked in for Friday afternoon now to have the temp sensor fitted and the MAF on its way from ebay, which should be working!

[ScoobyChris]

Glad it's not too serious and should be fixed by the weekend

Chris

[big k]

Well.... It would appear the MAF from my wreck is also under-performing, so I guess it is partially to blame for lack of boost BUT it is also the case that the temperature sensor is being "sporadic" too... Cheap to replace, but a the moment the car seems to think it's sometimes a lot colder than it really is, so the auto choke is kicking in and overfuelling the engine! :( Booked in for Friday afternoon now to have the temp sensor fitted and the MAF on its way from ebay, which should be working!

nah wouldn't have thought it was the temp sensor at fault !

[devonutopia]

nah wouldn't have thought it was the temp sensor at fault !

really? In combination with the dodgy MAF too? Oddly enough I had boost all the way home from the dealers, and none of the overfuelling symptoms.

[big k]

well in theory a dodgy maf should't over fuel that much either should be the other way and under fuel and put ecu in emergency mode and cut power big time

[Tech1e]

If its belching out black smoke it really sounds like a split turbo hose to me.

Could well be opening up as it tries to boost. Id have a look at the bottom intercooler pipe myself.

[devonutopia]

Trouble is with the split hose possibility is why would it be intermittent. Would it belch out smoke the whole time if there was a split? Also the choke like noise is quite odd too. I'll let them change the two sensors as both are up the creek anyway (or heading that way) and let them reset the faults, and see what happens.

Now I think of it, would a split hose cause the turbo (when it "does" spin up) to make an extra little noise, not normally heard?

Whereabouts is this pipe, and does it involve putting on a ramp and removing the plaggy engine cover and looking from underneath?

Cheers.

[devonutopia]

K - you describe almost exactly what happens - it does lose power and underfuel as you might say, but its when it reaches that 2000rpm level sometimes, it does the black belchy smoke thing, and STILL no power.

Could the lack of power be the MAF and the irregular fueling be the temp sensor screwing up the automatic choke or something?

Will follow up on the split hose too if possible.