Chipping - Page 2

solarman216 · 23-01-2013, 22:53

Quote:

Originally Posted by stinka

Ah I see, or a decent bleed valve.

I assume if the above chip works with the maf readings then it will increase fuel inline with increase in boost (as the maf senses boost pressure on td27)

the maf can only sense air flow volume, not pressure nor as far as I can tell temperature, Rick

solarman216 · 23-01-2013, 22:59

Quote:

Originally Posted by makeitfit

Nah, I think the maf sensor one tells the ECU the air is cold and so over fuels to match

think the maf can only sense air flow volume, not as far as I can tell temperature, on the petrol there is a separate temperature sensing device, one may possibly be incorporated in the diesel maf but if it is it is a separate device, rayf will be able to shed more light on this, and yes the only way to increase turbo pressure is to adjust the waste gate, Rick

makeitfit · 23-01-2013, 23:08

I thought the maf can only detect temp as a coefficient of air flow , as it's just a heated element that gets chilled by air flow.
So if it gets chilled a lot (or conned into believing that )the ecu delivers more fuel accordingly

stinka · 23-01-2013, 23:13

The maf senses boost pressure somehow

This was my fault when my truck was cutting out and going into limp mode throwing a code up for boost pressure. My old boss from when I was in trade 10 years ago is a diagnostic specialist and he has all dealer tools for most makes, he has a gen consult 2 and 3

Anyway he said the maf determines the boost pressure on the td27 eti as there is no map sensor or boost pressure sensor other than the maf, he did telle exactly how it does it but I'm fooked if I can remember

solarman216 · 24-01-2013, 00:29

sorry there is no possible way that the maff can read pressure, it reads volume of air flow end of story, it does this by comparing air temperature across a heated element and comparing it against a non heated element, and against known possible air flow through a known duct size, alter the duct size and the numbers will be meaningless, Rick

solarman216 · 24-01-2013, 00:38

Quote:

Originally Posted by makeitfit

I thought the maf can only detect temp as a coefficient of air flow , as it's just a heated element that gets chilled by air flow.
So if it gets chilled a lot (or conned into believing that )the ecu delivers more fuel accordingly

nice idea but not possible, the maf can only determine air volume with a heated element reference to an unheated element to determine air flow as per the parameters in the ECU, you need another device to determine temperature, Rick

stinka · 24-01-2013, 08:44

So how does the ecu determine a boost fault then if there is no sensor or pressure ?

makeitfit · 24-01-2013, 10:02

Quote:

Originally Posted by solarman216

nice idea but not possible, the maf can only determine air volume with a heated element reference to an unheated element to determine air flow as per the parameters in the ECU, you need another device to determine temperature, Rick

I was nearly there

The second element makes sense

makeitfit · 24-01-2013, 10:05

Quote:

Originally Posted by stinka

So how does the ecu determine a boost fault then if there is no sensor or pressure ?

Do the newer T2 have an extra sensor somewhere ? No way of doing it on mine circa '97

geoffdown · 24-01-2013, 10:15

Quote:

Originally Posted by makeitfit

Do the newer T2 have an extra sensor somewhere ? No way of doing it on mine circa '97

Or my x reg 2000 2.7tdi the ecu cant do anything bout it anyway unlike on the 3l which I belive the ecu controls the waste gate but on the 2.7 might as well piss in the wind as it cant do anything about this over boost code

stinka · 24-01-2013, 10:48

Quote:

Originally Posted by makeitfit

Do the newer T2 have an extra sensor somewhere ? No way of doing it on mine circa '97

The 2.7 etdi only has the maf, crank sensor, temp sender, throttle position sender, needle lift sensor, ecu and fuel pump

Nothing more on even late ones

The maf works out the boost pressure somehow guys as that was the fault on mine

solarman216 · 24-01-2013, 21:47

Quote:

Originally Posted by stinka

So how does the ecu determine a boost fault then if there is no sensor or pressure ?

not exactly sure, but if the boost fails then the lambda sensor will see a difference that I guess the ecu can work it out from that, and do not forget the maf will be well down to what it should be referrence revs, Rick

stinka · 24-01-2013, 22:12

No lamda sensor on a td27 mate

solarman216 · 24-01-2013, 22:53

Quote:

Originally Posted by stinka

No lamda sensor on a td27 mate

So I guess no Maf either, so does it really say if no boost? Rick

makeitfit · 24-01-2013, 23:04

MAF yes Lambda NO

Never seen that code either come to think of it.You sure that's not a 3.0 code

24-01-2013, 00:29	#20
solarman216 Off road maniac Join Date: Dec 2009 Location: Bexhill on Sea Vehicle: Y60 Patrol Me, 3 ltr Mrs Posts: 17,431	sorry there is no possible way that the maff can read pressure, it reads volume of air flow end of story, it does this by comparing air temperature across a heated element and comparing it against a non heated element, and against known possible air flow through a known duct size, alter the duct size and the numbers will be meaningless, Rick __________________ Ex banger racer now off road maniac Lokka on the front with manual hubs Diff lock on rear 3 inch SS straight through exhaust Manly winch bumper with 13000 lb winch 10 spike ground anchor, with multiple straps and blocks Super strong body cills capped with scaffold pole 20% stronger springs all round aggressive off road tyres on wheels so just swap. Aim to get stuck and be completely self sufficient in extraction, love getting muddy, 2ft deep is good but rare.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

23-01-2013, 23:08	#18
makeitfit Senior Member Join Date: Apr 2008 Location: on the beach WEST WALES Vehicle: Maverick TDi BLACK mmm Posts: 15,136	I thought the maf can only detect temp as a coefficient of air flow , as it's just a heated element that gets chilled by air flow. So if it gets chilled a lot (or conned into believing that )the ecu delivers more fuel accordingly

23-01-2013, 23:13	#19
stinka Senior Member Join Date: Feb 2012 Location: Staffs Vehicle: '02 Terrano TDI sport lwb Posts: 3,787	The maf senses boost pressure somehow This was my fault when my truck was cutting out and going into limp mode throwing a code up for boost pressure. My old boss from when I was in trade 10 years ago is a diagnostic specialist and he has all dealer tools for most makes, he has a gen consult 2 and 3 Anyway he said the maf determines the boost pressure on the td27 eti as there is no map sensor or boost pressure sensor other than the maf, he did telle exactly how it does it but I'm fooked if I can remember

24-01-2013, 08:44	#22
stinka Senior Member Join Date: Feb 2012 Location: Staffs Vehicle: '02 Terrano TDI sport lwb Posts: 3,787	So how does the ecu determine a boost fault then if there is no sensor or pressure ?

24-01-2013, 22:12	#28
stinka Senior Member Join Date: Feb 2012 Location: Staffs Vehicle: '02 Terrano TDI sport lwb Posts: 3,787	No lamda sensor on a td27 mate

24-01-2013, 23:04	#30
makeitfit Senior Member Join Date: Apr 2008 Location: on the beach WEST WALES Vehicle: Maverick TDi BLACK mmm Posts: 15,136	MAF yes Lambda NO Never seen that code either come to think of it.You sure that's not a 3.0 code