help with S70 please - Page 2

tractorman5720 · Sep 25th, 2011, 14:25

Quote:

Originally Posted by NI_Volvo_Nut

Sounds like the AA guy is a gimp!

There will be little to no pressure if the damn thing isn't running, my guess will be a fuel issue, check the fuel pump relay or check for power at the fuel pump

Then usual checks, spark, fuel compression....

It did start again when he turned up and this was when he did his 'test'.

tractorman5720 · Oct 1st, 2011, 15:43

After replacing the cat, the backbox, the plugs and the lambda sensor it turned out to be be the Mad sensor. If only I had checked that first.

Thanks for all the help and suggestions everyone.

Lmason · Oct 1st, 2011, 21:58

Quote:

Originally Posted by tractorman5720

After replacing the cat, the backbox, the plugs and the lambda sensor it turned out to be be the Mad sensor. If only I had checked that first.

Thanks for all the help and suggestions everyone.

which sensor is the mad sensor and where is it fitted on the car?

acshortt5 · Oct 1st, 2011, 22:35

Quote:

Originally Posted by Lmason

which sensor is the mad sensor and where is it fitted on the car?

Did you not know that any sensor automatically becomes a MAD sensor when it goes wrong....

tractorman5720 · Oct 2nd, 2011, 06:04

I thought I had edited that post to read MAF sensor. Using my phone to post at the moment as our pc broke down about the same time, which means predictive spelling. I have now added MAF to the dictionary.

Andy Northface · Oct 2nd, 2011, 08:47

My car often drives me MAD as well!! Welcome to the club mate!!

Your problem does sound very like Thanatos's problem he had with his MAP sensor! Is there much difference between a MAP and a MAF?

http://www.volvoforums.org.uk/showthread.php?t=135072

Chris_Rogers · Oct 2nd, 2011, 09:57

Yes, there is:

A MAP sensor reads manifold pressure (vacuum).

This is used in conjuction with air inlet temperature and engine rpm to calculate the mass of air going into the engine, this value is used to determine correct fueling

A MAF sensor reads Mass Air Flow directly.

acshortt5 · Oct 2nd, 2011, 11:05

Note that:

On pre me7 cars the "MAP" sensor is not a proper map sensor, in my opinion anyway. It sits behind the drivers side headlight on a bracket attached to the bonnet catch and it reads the atmospheric pressure (for altering the fuel trim for changes in altitude). But Volvo call it a MAP sensor and when it goes wrong the fault codes will say "MAP sensor".

ME7 cars have a proper MAP sensor located in the pipework going to the throttle body and do take a manifold pressure reading.

Chris_Rogers · Oct 2nd, 2011, 14:20

The sensor you refer to is a Barometric or Atmospheric Pressure sensor, the fault code confusion only happens when generic OBDII fault codes are read. Volvo diagnostics have a specific fault code for this sensor.

OBDII
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit
High Input
P0109 Manifold Absolute Pressure/Barometric Pressure Circuit
Intermittent

Volvo code is EFI-422

Oct 1st, 2011, 15:43	#12
tractorman5720 Junior Member Last Online: May 20th, 2013 13:02 Join Date: Jan 2011 Location: Byfleet	Fixed at last!! After replacing the cat, the backbox, the plugs and the lambda sensor it turned out to be be the Mad sensor. If only I had checked that first. Thanks for all the help and suggestions everyone.

Oct 2nd, 2011, 06:04	#15
tractorman5720 Junior Member Last Online: May 20th, 2013 13:02 Join Date: Jan 2011 Location: Byfleet	mad sensor?? I thought I had edited that post to read MAF sensor. Using my phone to post at the moment as our pc broke down about the same time, which means predictive spelling. I have now added MAF to the dictionary.

Oct 2nd, 2011, 08:47	#16
Andy Northface Where's that 18mm socket? Last Online: Apr 25th, 2016 23:01 Join Date: Sep 2010 Location: Normally in the dog house, Chester-Le-Street	My car often drives me MAD as well!! Welcome to the club mate!! Your problem does sound very like Thanatos's problem he had with his MAP sensor! Is there much difference between a MAP and a MAF? http://www.volvoforums.org.uk/showthread.php?t=135072 Last edited by Andy Northface; Oct 2nd, 2011 at 08:50.

Oct 2nd, 2011, 11:05	#18
acshortt5 Volvo Nutcase Last Online: Jul 14th, 2023 12:57 Join Date: May 2007 Location: N/A View Photos By: acshortt5	Note that: On pre me7 cars the "MAP" sensor is not a proper map sensor, in my opinion anyway. It sits behind the drivers side headlight on a bracket attached to the bonnet catch and it reads the atmospheric pressure (for altering the fuel trim for changes in altitude). But Volvo call it a MAP sensor and when it goes wrong the fault codes will say "MAP sensor". ME7 cars have a proper MAP sensor located in the pipework going to the throttle body and do take a manifold pressure reading. __________________ Andrew 1998 S70 T5 CD AUTO Previously a 1990 240 GLT-R

Oct 2nd, 2011, 09:57	#17
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	Yes, there is: A MAP sensor reads manifold pressure (vacuum). This is used in conjuction with air inlet temperature and engine rpm to calculate the mass of air going into the engine, this value is used to determine correct fueling A MAF sensor reads Mass Air Flow directly.

Oct 2nd, 2011, 14:20	#19
Chris_Rogers VOC Member Last Online: Apr 10th, 2017 16:55 Join Date: Jan 1970 Location: South Kent Coast	The sensor you refer to is a Barometric or Atmospheric Pressure sensor, the fault code confusion only happens when generic OBDII fault codes are read. Volvo diagnostics have a specific fault code for this sensor. OBDII P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input P0109 Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent Volvo code is EFI-422

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