Maf sensor

Thebald1979 · Apr 10, 2020

I have been thinking recently that my td5 should have a bit more grunt than it has, Don’t get me wrong it doesn’t go bad and runs really nice but i was starting to think it should have just a touch more power. Went through everything and found that the maf was getting power from ecu to the plug but when I unplug it and go for a drive it doesn’t make any difference at all to how it drives which indicates that it’s not working and needs replacing. My question is what would it drive like with it unplugged. Would it be lumpy or loss of power etc. I have removed and cleaned the map sensor which was pretty caked in crap but wondering maybe to replace that aswell

ronsealdeath · Apr 10, 2020

Not quite. You really need to plug it in to a diagnostic tool that can show live data. Otherwise the state of the MAF is a bit of guess work. Usually when knackered they run better with it unplugged but im not sure its a definitive test. The air flow readings are the only sure way to test it.
Lots of things cause a Td5 to be underpowered and in all honesty, they weren’t that quick from the factory. Check the AAP thingy and air filter, inlet manifold may be caked in crud, boost leaks, seized turbo actuator etc...
if you havent got a hawkeye/nano etc.. and are planning on keeping your Td5, i would invest in one. Will save you time and money in a year or so

sierrafery · Apr 10, 2020

Thebald1979 said:
My question is what would it drive like with it unplugged. Would it be lumpy or loss of power etc.

With it unplugged the engine should run very well(at about 95% of fully optimal behaviour) so if no notuceable difference you dont have to change it... it's also important what type of engine you have Eu2 or Eu3 and if you have EGR or not.

As said above you need a tester to properly diagnose it

Thebald1979 · Apr 10, 2020

Egr has been blanked properly. Air filter all good and actuator not seized as that’s all been checked. Will check over for boost leaks thoroughly. It has had the boost modulater bypassed and has a direct feed. Turbo seems to be all ok. It’s a 10p Lump on a 2000 plate. Like I say it runs very well and drives fine just thought it should have a bit more grunt as runs out of it at about 50-60

sierrafery · Apr 10, 2020

Thebald1979 said:
Egr has been blanked properly......It’s a 10p Lump on a 2000 plate.

Then the MAF is no factor, what size of tyres you have?

Thebald1979 · Apr 10, 2020

235/70/17 but soon to putting 245/75/16’s on it.
Like I say it’s not stupidly slow I just felt it needed a bit more. Thinking of getting an alive map soon anyway

sierrafery · Apr 10, 2020

Check the turbo hoses to not be soft, with the bigger tyres will be even more sluggish without a proper remap, tell to the remappers the tyre size you'll have on it cos it's important

Thebald1979 · Apr 10, 2020

To be fair the hose from the air box to the turbo is softish

sierrafery · Apr 10, 2020

That's intake hose, i meant turbo(boost) hoses(turbo-intercooler-inlet) cos those can affect power if they are delaminated

Thebald1979 · Apr 10, 2020

Ah I see ok will check them Thankyou.

sierrafery · Apr 10, 2020

I forgot to say, to gain a bit of throttle response tighten the wastegate rod as to let 10 threads out from the locknut toward the valve(on factory setup there are 13)

Thebald1979 · Apr 10, 2020

I have done that already. What sort of Bhp will a map give. What other engine mods that don’t cost the earth could I do to make it better apart from the map.

sierrafery · Apr 10, 2020

The BHP and torque depends on the map version, more setups are available up to 30% power gain, as for costless tunings other than the wastegate adjustment not really, deleting the middle silencer and silicone turbo hoses might help a bit(or not)

Thebald1979 · Apr 10, 2020

Was going to get silicone hose kit to be honest plus a centre silencer delete as that’s pretty cheap. Going to get a decent panel filter too with a snorkel kit. Someone said to me to disconnect the breather hose from the top of the rocker cover and blank it off on the air intake hose. Is that a good move?

Thebald1979 · Apr 10, 2020

Obviously tie the breather hose up somewhere out the way with maybe a gauze or oil catch bottle

sierrafery · Apr 10, 2020

Thebald1979 said:
Someone said to me to disconnect the breather hose from the top of the rocker cover and blank it off on the air intake hose. Is that a good move?

IMO that's a silly move as that way the crankcase breather system is disabled and there will be excessive depression in the crankcase, the depression control valve is there for a good reason as to close when the revs are high otherwise the valve seals can suffer, eventually you can fit a catch can for the oil which has it's own DCV but they work together with the sucction from the intake.... who recommended that knows nothing about that

Thebald1979 · Apr 10, 2020

Thankyou so much and this is why I always ask the people that know about these things before I do anything.

Stanleysteamer · Apr 10, 2020

Thebald1979 said:
Was going to get silicone hose kit to be honest plus a centre silencer delete as that’s pretty cheap. Going to get a decent panel filter too with a snorkel kit. Someone said to me to disconnect the breather hose from the top of the rocker cover and blank it off on the air intake hose. Is that a good move?

In my experience, deleting the centre silencer is a waste of time. Made no noticeable difference at all.

Thebald1979 · Apr 10, 2020

Does it not at least make it sound better?

ronsealdeath · Apr 11, 2020

Some tuners dont like snorkels and I believe you lose power and mpg with them fitted. Ive never fitted one so cant confirm.
Centre pipe delete should be done in conjunction with a remap to see benefits. Its all about getting the engine breathing better which would allow the remap a bit more scope. Loads on here do a search.
The centre muffler stops the droning noise at speed which can be annoying on long journeys if you remove

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