scoping MAF-MAP on late diesels

Ask any questions relating to the PicoScope hardware or kit contents here.
If you have any questions prior to purchasing the kit post them here.
sapper826

scoping MAF-MAP on late diesels

Post by sapper826 »

Hi! all, tried scoping MAF/MAP on 08 Astra D, and Fiat Punto 07 13 JTD. The waveforms are all like 0v-5v hall effect, and only get closer together on snap throttle, any way of testing them?
TIA

User avatar
Matt Fanslow
OneWave
OneWave
Posts: 15
Joined: Wed Aug 01, 2007 8:38 pm
Location: MN

Re: scoping MAF-MAP on late diesels

Post by Matt Fanslow »

For one, it is difficult to analyze a pulse-train such as what you are describing with the MAF and MAP sensors. Scoping the pulse-train will allow you to monitor the signal integrity and watch for catastrophic signal breakdowns.

PicoScope 6 (6.4.28) with a 4000 series DSO will allow you to look at Frequency up to 20kHz. I don't know the operating range of the sensors you speak, so this may or may not allow you to test to the upper limit of the sensor. Graphing frequency, however, would lend itself better to testing for a skewed sensor.

HTH. Later, Matt.

Guest

Re: scoping MAF-MAP on late diesels

Post by Guest »

[quote="Matt Fanslow"]For one, it is difficult to analyze a pulse-train such as what you are describing with the MAF and MAP sensors. Scoping the pulse-train will allow you to monitor the signal integrity and watch for catastrophic signal breakdowns.

PicoScope 6 (6.4.28) with a 4000 series DSO will allow you to look at Frequency up to 20kHz. I don't know the operating range of the sensors you speak, so this may or may not allow you to test to the upper limit of the sensor. Graphing frequency, however, would lend itself better to testing for a skewed sensor.

HTH. Later, Matt.[/quote]

thanks for your reply, will work on the graphing.

Dave Hill
TwoWaves
TwoWaves
Posts: 63
Joined: Fri Jun 22, 2007 8:15 am

Re: scoping MAF-MAP on late diesels

Post by Dave Hill »

Hi Matt

I don't know which version of pico software that I am running, but I think I can only have a 2khz frequency range. Has this been increased to 20khz, or is that a typo?

Ordinarily I could check to see, but with only an iPhone to connect to the net, I am a bit limited. :?

I really hope that the Pico crew have increased the range, as it will be very useful.

Regards

Dave

mapengo
OneWave
OneWave
Posts: 16
Joined: Sat Aug 30, 2008 9:08 pm
Location: Warrington, Cheshire

Re: scoping MAF-MAP on late diesels

Post by mapengo »

Matt Fanslow wrote:For one, it is difficult to analyze a pulse-train such as what you are describing with the MAF and MAP sensors. Scoping the pulse-train will allow you to monitor the signal integrity and watch for catastrophic signal breakdowns.

PicoScope 6 (6.4.28) with a 4000 series DSO will allow you to look at Frequency up to 20kHz. I don't know the operating range of the sensors you speak, so this may or may not allow you to test to the upper limit of the sensor. Graphing frequency, however, would lend itself better to testing for a skewed sensor.

HTH. Later, Matt.
Hi Matt,

Are you saying that we can now graph the frequency from a digital MAF?
Enabling us to see a conventional MAF waveform shape with the "gulp" from a digital MAF.
If so can you post a screen capture with settings please?

Cheers

Doc...

User avatar
Matt Fanslow
OneWave
OneWave
Posts: 15
Joined: Wed Aug 01, 2007 8:38 pm
Location: MN

Re: scoping MAF-MAP on late diesels

Post by Matt Fanslow »

My apologies for the delay. Here is a capture


Image

Later, Matt.

mapengo
OneWave
OneWave
Posts: 16
Joined: Sat Aug 30, 2008 9:08 pm
Location: Warrington, Cheshire

Re: scoping MAF-MAP on late diesels

Post by mapengo »

Many thanks Matt,

Cheers

Doc...

User avatar
Matt Fanslow
OneWave
OneWave
Posts: 15
Joined: Wed Aug 01, 2007 8:38 pm
Location: MN

Re: scoping MAF-MAP on late diesels

Post by Matt Fanslow »

I've received some comments about the spikes on the frequency graph. I've taken a second capture with a greater number of requested samples and loaded it here: http://www.wavehook.com/dbase/bigpic.ht ... d=1599.gif. You can download the .psdata from there and manipulate it as you please.

mapengo
OneWave
OneWave
Posts: 16
Joined: Sat Aug 30, 2008 9:08 pm
Location: Warrington, Cheshire

Re: scoping MAF-MAP on late diesels

Post by mapengo »

Nice one Matt 8) ,

Appreciated

doc...

Alan
Pico Staff Member
Pico Staff Member
Posts: 264
Joined: Thu May 25, 2006 8:02 am

Re: scoping MAF-MAP on late diesels

Post by Alan »

Matt,

Thanks for the post and comments about the spikes.

The 0 to 20kHz range is there to allow the scoping of "digital" MAF sensors but its a bit of a work in progress at the moment.

The spikes are due to it being very sensitive to noise. We have this sorted in a alpha version of the software but you will need to be patient before you can have a copy!

I will put together some notes on this an post later.

Regards
Alan

Post Reply