Fun MOT Time...

[SupStacey]

It's that time of year again... MOT on our X reg fun.

 

Having already had a new exhaust, Cat & Lambda fitted earlier in the year, is there any other reason why (other than a shoddy fitting) it would fail on emissions?

 

There are a few other minor things too.

It may be the end of the old girl... perhaps she can find a better life with a new owner :(

 

This isn't me asking how much i should sell her for, but could anyone tell me how much they purchased their fun for?

Currently for sale I can only see prices of the area of £1.5K in great condition, or something stupid like £100 for a shell and a non-working engine... not exactly the best market to try and find a price for!

 

 

 

(i will totally take out my last question if its not appropriate)

Edited 2 October, 2014 by SupStacey

[TeflonTom]

Hi

what were the emissions readings?

[SupStacey]

Hi Tom. Stupid me left the certificate at home - i will take a look and pop them up here later. I think it failed on everything except idle... but not certain until i double check.

[TeflonTom]

Ok, let us know.

[SupStacey]

Managed to get a picture hope this helps?

[TeflonTom]

Ok, it's running far too rich... There are a few possibilities here, although your lambda probe is new, it could be faulty, so bare that it mind, the HC (hydrocarbon) reading is a pass but I would expect that to be below 15 parts per million, high HC and co readings simultaneously indicates a rich mixture or unburnt fuel in the exhaust gas, if it was high co on it's own I would point to the cat being at fault

So it's either a faulty lambda probe, or there is an exhaust system leak before or near to the catalytic convertor which is allowing air to be drawn in and is fooling the ecu into over fueling.. Is the exhaust system noisy or sound blowy? If not try a different probe in there.

[dohnjoe]

if the car idles naturally between 590 and 840 rpm I'd say that is a very rough idle.

that looks like a vacuum leak or dirty throttle body.

[SupStacey]

Thanks Tom, that does make sense as the exhaust is noisy, didn't realise a blow would cause it to fail though.

We'll take a look at the exhaust. I'm super annoyed because the mot guy did say it was the worst fitting of an exhaust he's ever seen. Covered in paste apparently? Sigh! Thanks so much for you help though

If I put the fail results up on here too, do you reckon you might be able to see if we have a really poorly fun or are perhaps being ripped off??

[TeflonTom]

Yeah, what did it fail on?

It's normal to have a bit of paste at the joints, it's a sealant which you squueze out of a tube like toothpaste, and once it gets warmed up by the exhaust system it goes off like concrete, normally you would put some on the slip joint where it slides over the adjoining exhaust piece, it helps get a gas tight seal.

[TeflonTom]

The other possible thing is that the exhaust manifold has cracked, it's really common on the 1.6 engines, seen here in the pic, this also sometimes allows a bit of air into the exhaust gasses which fools the lambda probe into thinking the engine is running lean so it squirts more fuel in to compensate. And further more this particular one in the picture didn't even make a noise, you would have never known it was cracked because it's not visible, a heat shield bolts on over the top of this so it would be obscured from view.

[SupStacey]

Dohnjoe it does idle very low on start ups but is then absolutely fine once you drive away. I don't think the throttle has ever been cleaned...

Defo not a crack in the manifold - bloke has been on the phone again today and it's leaked gas from every join... Oh joy!!

I'll take a picture of the cert now... Only had the emissions one at home before and have this one now

[TeflonTom]

Oh dear... That's going to need some serious money spent on it, it's going to need somebody to do a fair amount of welding on it by the looks of it, the rest of the stuff is superficial..

It's sad really, but these fun truck do rust up pretty badly.

[SupStacey]

Yeah, we've been quoted over £900 and that's if they don't come across anything else amiss...

It's a shame as the mot runs out at the start in November and then we are getting married so just can't afford it :(

We have a friend who is a welder, we are hoping he'll be able to help somewhat and bring the cost down otherwise it's rip little truck :(

[Skodle]

Thanks, SupStacey, for this thread - these mysterious emissions tests are a bugbear for so many of us!

Although I agree that the highish CO suggests over-richness, I am puzzled by your thumbnail of the test report which flags the second lambda of 1.03(limits 0.970 -1.03) as a FAIL. Summat wrong there! (I have before me a recent test report on a marginal Felicia, albeit generated by different software, which correctly flags a lambda of 1.03 as PASS).

In my experience, our worthy MOT test stations are not experts in calibration of their test equipment, and they are certainly not up to debugging underlying software. Do not take their results as gospel truth!

TeflonTom, your #6; I don't quite understand how an exhaust leak might upset the control system, can you elaborate, please?

[TeflonTom]

Ok, there are some fundamental things you need to understand first, a lambda probe (0xygen probe) basically acts as a switch as far as the ecu sees it, it measures the oxygen content of huge exhaust gas, it has 2 states in which outputs a voltage, either 0.3volts or 0.6 volts approx, you get 0.3 volts when the mixture is lean, 0.6 when it's rich,

Ok, so your closed loop fuel injection system uses this input tried voltage to determine a lean/rich condition, since there is only 2 states, or effectively just an on/off the ecu needs to add fuel or take away fuel constantly, it does this every 2 seconds or so, over time the ecu learns how much fuel trim is needed to keep the mixture presentation hovering over th correct stoichemetric ratio, but it still fluctuates rich /lean every 2 seconds so that it knows the required mixture is in the middle of the 2 values... Still following? This is called hysteresis.

Adaption, there is a system built into the software programming of the ecu which allows the mixture to be trimmed rich or lean a certain percentage based on wear and tear of components, compression, temperature changes, barometric changes etc, effectively it learns over time the correct air fuel ratio to use..

now, you have spring a leak in your exhaust system before the cat, an amount if air is drawn into the exhaust system, the lambda probe reads this as the engine running lean, so it assumes that it needs to add fuel, so it enriches the fuel mixture assuming that it will soon go rich again, but the higher gas volume draws in more air, which in turn adds fuel and so on, it won't go on indefinitely however, the adaption has a limit, after which it ceases to make it go richer, it assumes that there is a fault with a sensor reading, in which case it will automatically default to a rich fuel mixture setting, a lean engine runs hot, a rich engine runs cooler, rich is safer.

[Skodle]

Thank you, much appreciated.

I have been very favourably impressed by the Favorit LXi management system, which has given me no problems. Do the ones on the Felicias compare well, or are they more inclined to be tetchy?

[SupStacey]

Wow, that went completely over my head! lol.

 

It has always been terrible on fuel, so if it's running rich that doesn't surprise me. I just hope we can save her :(

 

We have a few friends who are "mechanically able", and are hopefully going to have a look and see if they can help us out... Watch this space, I guess!

I don't think i could bring myself to scrap her. I wonder if there is a quirky organisation or company out there that might want some free advertising on her in trade for repairs...

[SupStacey]

Wedding out of the way... meaning we can get some funds on the go and get her back on the road again...

I'm looking at taking a car restoration course at a local college (10 week - £130, I think that's pretty good!) which teaches welding amongst other things - so hopefully with a bit of help she'll be SORN'd no longer!

 

Watch this space...

P.s if anyone is in Bristol one weekend and wants to lend a hand...