MAF again - I think!

[zippy]

I think I succumbed to the MAF problem. Was changing the air filter on Tuesday, when I found it was the wrong one fitted - too small. Well there were flys and leaves and crap in and around the MAF.

Silly me brushed them out - should have hoovered them:doh.

Anyhow, next morning T2 started lovely but no power at all - would not get up my drive. I thought it must be the MAF since i was farting around that area the night before. Since we were going away that morning in the caravan, I pulled the plug to the MAF and low and behold got enough power to tow the caravan! Not full power but enough. Also the MPG dropped by nearly half.

Once I got to our caravan site, i bought some switch cleaner and some cotton buds. Cleaned the entire assembly and now have much more power and better fuel economy:thumb2 than even before i had the problem. However, I am getting much more in the way of black sooty deposits on my caravan now.

Some questions -
1. Will disconnecting the sensor and driving for 100 miles have done any damage to the T2?
2. What is the purpose of the MAF?
3. Why am i now getting better power, better MPG but more black smoke? I thought black smoke was a sign of a knackered maf.
4. Can i sort out the black smoke - only a problem when towing the caravan?

Cheers
Lee
ps. Thanks for this site - would not have had a clue what to do and would have probably had to cancel our mid-week break!:bow

 

[lacroupade]

I can answer some of that Zip.

You shouldn't have done any damage first of all, so don't worry.

Not clear what you meant about the air filter - are you saying the one fitted didn't fill the airbox?

The MAF is fairly simple; its a heated wire that sits in the airflow and sends a signal back to the ECU to tell it how much its being cooled by the airflow....on the basis that it doesn't matter if that cooling is caused by MORE air going through or COLDER air going through - either way it means more oxygen available to burn, so the ECU squirts a bit more fuel in. Obviously therefore, if the wire has crap on it, that will help keep it warmer and so less fuel will get in for more air.

The better power and mpg are because your MAF wire is now clean, and doing its job properly, as well as your air filter, if its bigger than the old (wrong) one, having more surface area and letting more air in.

As regards the soot, theres been a long thread on that somewhere - search "soot caravan" and see what pops up....

 

[BigBlack]

I'd recon that the increase in soot is down to the better fueling... I think if you stick some injector cleaner in your tank next time you fill it that cuts down the soot.

My caravan's always covered you could try sticking one of them chrome tail pipes on the end to blow it towards the road?

 

[lacroupade]

well black smoke normally indicates unburnt fuel - but a dose of injector cleaner won't hurt, as well as making sure you use decent diesel, i.e. BP, Shell etc.., not supermarket stuff.

 

[tezzer]

you could always do colin on it, fit a extreme stack pipe to the side of your truck,:lol <a href="http://plugin.smileycentral.com/http%253A%252F%252Fwww.smileycentral.com%252F%253Fpartner%253DZSzeb008%255FZSfox000%2526i%253D3%252F3%255F2%255F105%2526feat%253Dprof/page.html" target="_blank"><img src="http://smileys.smileycentral.com/cat/3/3_2_105.gif" alt="SmileyCentral.com" border="0"><img border="0" src="http://plugin.smileycentral.com/http%253A%252F%252Fimgfarm%252Ecom%252Fimages%252Fnocache%252Ftr%252Ffw%252Fsmiley%252Fsocial%252Egif%253Fi%253D3%252F3_2_105%2526uiv%253D3.0/image.gif"></a>

 

[Deleted account DD]

I give mine a blast out with millers, seems to do the trick.

I do quite a few miles with the van on the back and do not have a soot problem on the front of it. I would agree with the engine not burning it properly option.

 

[harlowmaverick]

me being dumb i guess

whats a maf?

 

[extreme-4x4]

mass air flow sensor:thumbs

 

[harlowmaverick]

now i know!
lol
cheers extreme

 

[zippy]

I can answer some of that Zip.


Not clear what you meant about the air filter - are you saying the one fitted didn't fill the airbox?

....

Thanks for the replies. The air filter i took out was rattling in its housing. Not a good fit which meant that the air could bypass the filter and deposit lots of leaves/flies/crap onto the MAF. The air filter i fitted was a much better fit, so i should not have the same probs again.

The black soot - still dont know why it should happen, given the improved mpg anf power. If the fuel is only partly burnt then surely mpg should go down?? I will maybe try some redex or such like to see if it improves, otherwise i need to source a downward pointing tail pipe!

Thanks
Lee

 

[zippy]

I give mine a blast out with millers, seems to do the trick.

I do quite a few miles with the van on the back and do not have a soot problem on the front of it. I would agree with the engine not burning it properly option.

What is Millers? Is it like Redex? I will try some of it if i can source it.

Thanks Lee

 

[jimmy92]

Hi iv got a bosch maf that came off my car that i no is a good one if anybody is interested. thanks:thumb2

 

[ssteve]

white smoke = unburnt fuel
black smoke=starved of air (fuel not fully burnt) or overfueling or it's clearing the crap out of the system when working hard but should clear after a while

ssteve

 

[Deleted account DD]

What is Millers? Is it like Redex? I will try some of it if i can source it.

Thanks Lee

yes it is, its supposed to up the cetane rating as well as clean out the crap and keep it clean.

I first cottoned onto it at our local motor factors , who's a down to earth bloke no need to bullshit, when I was asking about redex type products. He was telling me (and I've seen them since :thumb2 ) about the local taxis. When its getting close to mot they get a bottle, massively overdose and it cleans it up. One reckoned that alone brought the emmisions down to a pass.

Just be careful where you source it. I paid £7.50 for a bottle a week ago from him, I've seen it in Halfords for over £10

 

[lacroupade]

Millers Diesel Power Plus or Diesel Power Sport 4.

As ssteve says, the ECU takes a while to relearn the new airflow characteristics, so the soot thing may disperse after a few miles. But won't hurt to run some of the above through it.

If you have an intercooler, it might be worth whipping it off and blowing air through in reverse direction, as a lot of that shite might have got through the turbo and started to block the airways...you can flush it with solvent or petrol (but be careful for obvious reasons and let it dry completely before refitting).

 

[Deleted account DD]

Diesel Power Sport 4.

:thumb2 thats the latest one. couldnt remember the name.

 

[lacroupade]

:thumb2 thats the latest one. couldnt remember the name.

Mighty be too good for ours! LMAO

 

[ssteve]

up the cetane rating! stick 10% petrol in it!

ssteve

 

[zippy]

Thanks for all the replies. Will try the millers first then take it for a jaunt up the motorway.

cheers
Lee

 

[lacroupade]

up the cetane rating! stick 10% petrol in it!

ssteve

Extreme keeps on about that. Ever tried it Steve?