Maf brand matter?

[Yungog]

Buying a new maf sensor. Car is a 04 cmax 1.6tdci.

Found new ones on eBay like this one for about £45

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F131719532148

Carparts4less has a branded pierburg one for £109.

So there's some difference in price and wondering is the pierburg one better in terms of sensors internally or would the £45 one do?

Thanks

[TomsFocus]

With sensors you do usually get what you pay for.  Cheap MAFs are usually crap in my experience. 

[Micro]

Check Eurocarparts also, and use the discount codes they advertise. The £150 sensor is likely to be closer to £100 with the discount codes. Also remember to check Ford dealers on eBay and fordpartsuk.com

[rhyds]

From what I've been told, the difference between cheap MAFs and proper ones is in the calibration and accuracy. 

Basically, the cheap MAFs read somewhere close to accurate at (for example) idle and wide open throttle, however they don't match a proper MAF's signal curve between those two points, meaning the new MAF may not be any better than the duff one you're taking out. Personally I'd bite the bullet and buy a proper MAF rather than a cheap one. 

[Yungog]

Thanks lads,I'll go for the expensive one.

I have acceleration issues,that's why I was gonna get a new maf but been told by someone else it not the problem.

Basically what happens is when I the turbo boost kicks in, it boosts for a second around 2k revs then stops then kicks back in from 3k to 4k revs.

I used an obd and torque app and measured the maf reading and the boost reading.

When it works properly the readings increase together.

When the problem happens the maf reading drops from say 80g/s to like 50g/s ,then a second later goes back to normal.

Am I right in thinking if I disconnect the maf sensor and drive for awhile and if the problem doesn't happen then its defo the maf?

Thanks sorry for the grappy explanation 

[TomsFocus]

Can you use FORScan with your OBD dongle?  Might pull up some Ford specific fault codes with that.  You may find that it's getting an over-boost fault at 2k so backing off to avoid any damage.  Also check the EGR isn't opening when the MAF figures drop.  As the EGR redirects gas back into the engine, less is drawn in through the MAF, the EGR should be closed under hard throttle though.

The usual MAF test is if the car runs the same or better with the MAF unplugged then the MAF is at fault.  If it runs worse when unplugged then the MAF is working.

Is this a 90 or 110ps model btw?

 

[Yungog]

2 hours ago, TomsFocus said:

Can you use FORScan with your OBD dongle?  Might pull up some Ford specific fault codes with that.  You may find that it's getting an over-boost fault at 2k so backing off to avoid any damage.  Also check the EGR isn't opening when the MAF figures drop.  As the EGR redirects gas back into the engine, less is drawn in through the MAF, the EGR should be closed under hard throttle though.

The usual MAF test is if the car runs the same or better with the MAF unplugged then the MAF is at fault.  If it runs worse when unplugged then the MAF is working.

Is this a 90 or 110ps model btw?

 

I actually only bought a modified elm327 cable the other day and activated cruise control. So I'll hook that up and check for fault codes once the snow f**ks off as the laptop needs to be plugged all the time. The bluetooth obd I use is a crappy Chinese $2 one and that's only reading one code,p138b. And that relates to the glow plugs.

Egr is blanked off so shouldn't be an issue with that.

Will try disconnecting the maf and test it without when I'm going for a good run, was just worried about doing damage with it running lean.

Its the 110bhp model.

Thanks

[TomsFocus]

It'll actually run a bit rich with the MAF disconnected, it uses a fail-safe map to avoid leaning out and melting the engine together lol.  So you'll probably get a bit more smoke and lose some mpg if the MAF was good.  I've known people run for years with a maf unplugged rather than buy a new one!

As it's the 110 it's got a VNT turbo so sticky turbo vanes are another possibility.

[Yungog]

On 3/3/2018 at 7:51 PM, TomsFocus said:

It'll actually run a bit rich with the MAF disconnected, it uses a fail-safe map to avoid leaning out and melting the engine together lol.  So you'll probably get a bit more smoke and lose some mpg if the MAF was good.  I've known people run for years with a maf unplugged rather than buy a new one!

As it's the 110 it's got a VNT turbo so sticky turbo vanes are another possibility.

Sorry for the late reply.

Disconnected the maf a few days ago.

Car feels smoother through the revs, haven't noticed any boost issues with it been disconnected.

Can you tell me how to check the turbo vanes and where it is?

I've replaced the turbo pressure solenoid ( the brown box with 3 tubes going to it) about a year ago.

[TomsFocus]

The turbo vanes are inside the exhaust side of the turbo so not visible without dismantling it.  

If you look at the bottom of the turbo you'll see the rod that the boost solenoid pulls a vacuum on.  If you watch it while someone else starts and revs the car you should see it move smoothly.  

Sounds like it might be the MAF from your test though.

[Yungog]

On 3/16/2018 at 11:45 AM, TomsFocus said:

The turbo vanes are inside the exhaust side of the turbo so not visible without dismantling it.  

If you look at the bottom of the turbo you'll see the rod that the boost solenoid pulls a vacuum on.  If you watch it while someone else starts and revs the car you should see it move smoothly.  

Sounds like it might be the MAF from your test though.

Checked the turbo actuator rod and it moves up and down when its revved ,tho I wouldn't say smoothly.

It does move so I'm guessing that the vanes aren't knackered?

Should have the maf by the end of the week so boost issue will hopefully be fixed when it arrives :D

[Yungog]

On 3/19/2018 at 8:11 PM, Yungog said:

Checked the turbo actuator rod and it moves up and down when its revved ,tho I wouldn't say smoothly.

It does move so I'm guessing that the vanes aren't knackered?

Should have the maf by the end of the week so boost issue will hopefully be fixed when it arrives :D

So maf arrived today.

Took it for a drive.

Seemed OK but I was taking readings on the torque app.

The maf reading is constantly at 119.4 g/s. My limited knowledge suggests it should vary in g/s readings. But it constantly at 119.4g/s.

The old maf was getting readings from 9-80 g/s.

Any ideas if its a faulty unit?

[TomsFocus]

It should vary yeah, that looks like a default figure.  I'd check the plug is in tight just in case lol.  Did you reset the MAF adaptions through FORScan?

 

[Yungog]

24 minutes ago, TomsFocus said:

It should vary yeah, that looks like a default figure.  I'd check the plug is in tight just in case lol.  Did you reset the MAF adaptions through FORScan?

 

Lol plug is as tight as its gonna get.

I've cleared the faults only through torque app on my phone.

How do I reset its adaptions through forscan?

[TomsFocus]

It's under something like 'service procedures', been ages since I've needed to do anything like that so can't remember 100%.  It should be obvious when you find it though, will be under PCM if you have a choice of modules.

 

[Yungog]

Just now, TomsFocus said:

It's under something like 'service procedures', been ages since I've needed to do anything like that so can't remember 100%.  It should be obvious when you find it though, will be under PCM if you have a choice of modules.

 

Sound will hook it up to the car soon and try it.

Does this need to be done every time the maf is disconnected? 

If not it will keep the default value even if an maf sensor is plugged in?

[TomsFocus]

It should only need doing when you've got a new sensor as it's currently adapted to the old sensor.

[Yungog]

So hooked up laptop to the car.

Wiped and re read DTC codes.

Getting pcm0103-61 constantly.

Under the service procedure I reset intake air throttle valve position offset.

There's nothing about clearing adaptions 

There is PCM module reset.

Would that be it?

[TomsFocus]

The air intake throttle valve is a separate part and not relevant for this.

PCM reset is definitely worth a try but it's not the procedure I was thinking of.  If I get the chance tomorrow I'll plug mine in to see if I can find the MAF one.

It does look like you've got a faulty MAF or wiring issue with that constant fault though.  Have you tried plugging the old one back in to see if it still works as before or if both cause the same fault now?

 

[Yungog]

1 hour ago, TomsFocus said:

The air intake throttle valve is a separate part and not relevant for this.

PCM reset is definitely worth a try but it's not the procedure I was thinking of.  If I get the chance tomorrow I'll plug mine in to see if I can find the MAF one.

It does look like you've got a faulty MAF or wiring issue with that constant fault though.  Have you tried plugging the old one back in to see if it still works as before or if both cause the same fault now?

 

Sound.

Ye I'm pretty sure its faulty.

The code went away as soon as the old one was put back in.

This is a picture of the top of it.

A friend suggested it looks tampered with or it was damaged and attempted to be fixed.

I've never seen one with this gold on top

[Tdci-Peter]

10 hours ago, Yungog said:

The maf reading is constantly at 119.4 g/s.

It certainly sounds like it is wrong, probably reading full range.

For a 1.6l engine, even if it pulled in the full volume each 2 revs (4 cyl, 4-stroke), and had a MAP reading  of 2.4 bar abs (1.4 bar or about 20psi of boost), and at 3000rpm, then the air flow would be 1.6 x 3000 / 2 / 60 x 2.4 x 1.2 grams/sec = 115 g/s.

And a lot less at lower rpm, or lower boost pressure. Also it is unlikely to suck in the full 1.6l, in reality.

By comparison, a Forscan run I did recently on my 1.8, gave 106 g/s at 2500rpm and 2.1 bar MAP reading. And 11g/s at idle.

Doing that calc on those figures gives 94g/s, I wonder now if my MAF is reading a bit high? But that is not relevant here, what is more relevant is that the 9 to 80 g/s from the old MAF is not far off being right, maybe a tiny bit low. What I think was wrong was the sudden, unexplained dips in the reading that were seen. Could that possibly have been a bad connector?

[TomsFocus]

11 hours ago, Yungog said:

Sound.

Ye I'm pretty sure its faulty.

The code went away as soon as the old one was put back in.

This is a picture of the top of it.

A friend suggested it looks tampered with or it was damaged and attempted to be fixed.

I've never seen one with this gold on top

Is that actually branded Pierburg?  Where did you buy it?  The gold solder is just the connections between the MAF and the plug part on top, but very odd to have it exposed.  

[Yungog]

12 hours ago, Tdci-Peter said:

It certainly sounds like it is wrong, probably reading full range.

For a 1.6l engine, even if it pulled in the full volume each 2 revs (4 cyl, 4-stroke), and had a MAP reading  of 2.4 bar abs (1.4 bar or about 20psi of boost), and at 3000rpm, then the air flow would be 1.6 x 3000 / 2 / 60 x 2.4 x 1.2 grams/sec = 115 g/s.

And a lot less at lower rpm, or lower boost pressure. Also it is unlikely to suck in the full 1.6l, in reality.

By comparison, a Forscan run I did recently on my 1.8, gave 106 g/s at 2500rpm and 2.1 bar MAP reading. And 11g/s at idle.

Doing that calc on those figures gives 94g/s, I wonder now if my MAF is reading a bit high? But that is not relevant here, what is more relevant is that the 9 to 80 g/s from the old MAF is not far off being right, maybe a tiny bit low. What I think was wrong was the sudden, unexplained dips in the reading that were seen. Could that possibly have been a bad connector?

Ye the main issue is that lag in boost.

Also been getting worse mpg.

I did a reading awhile ago of the old maf and boost while driving. Normally they both increase then all of sudden the maf would reading would drop all of a sudden and that's when the boost would stop and drop then pick up a few seconds later.

Checked for leaks and there's none anywhere.

My limited knowledge indicates to me a faulty maf.

Checked all connections and all were good. I haven't noticed the problem since the maf has been disconnected.

2 hours ago, TomsFocus said:

Is that actually branded Pierburg?  Where did you buy it?  The gold solder is just the connections between the MAF and the plug part on top, but very odd to have it exposed.  

Yep has a little sticker on it saying pierburg,came in a pierburg box.

Bought it from mister auto online. Always get my car stuff from them and never had an issue with them before.

Although what I noticed was the pierburg box had been opened prior to me getting it as the sticker that holds the flap down was ripped open!

Ye its very odd it showing the connections.

It feels and looks like silicone/glue over it. Defo doesn't look like it should be like that. That's why we thought it was tampered with/repaired .

[TomsFocus]

Fair enough, I've not had an issue with Mister-Auto before either.  I would guess someone's already returned that as faulty/wrong and they've sent it straight to you without checking it...  I've had the same happen with ECP before.

I can't find any close up pics of that Peirburg MAF online but there are other brands of the same MAF which don't have the exposed part on top.  It's different to the later models which used a separate MAF from the plastic tube so can't compare it to my own.  Either way, I reckon send it back and get another.  Make a small mark on somewhere so you'll know if they send you the same one back lol.  

[Tdci-Peter]

2 hours ago, Yungog said:

Normally they both increase then all of sudden the maf would reading would drop all of a sudden and that's when the boost would stop and drop then pick up a few seconds later.

Checked for leaks and there's none anywhere.

First step, like Tom says, is get the dodgy MAF replaced or refunded. A good supplier should send you a pre-paid address label in a case like this where the goods are not as described. If it said new, unused, and with no comment about poor packaging, then your unit is SNAD. I had this a couple of times last year. A coupe of good photos is usually enough to convince them.

Airflow problems are a bit of a pig, it is all so inter-dependant. A fall in boost pressure will make the air flow (MAF reading) drop immediately, as less air is going in. A fall in MAF reading (due to a fault), I would not expect to make an immediate fall in boost (MAP). Only if the ECU read the fall from the MAF and deliberately cut the turbo boost, would the MAP fall, so there should be a delay.

I am looking at this on my car a bit, I have been getting the odd P0299 error for ages (Turbo underboost), but it is getting a bit more frequent. So I have been recording MAF & MAP. They normally seem to track quite closely, though RPM will affect MAF in a different way to MAP. Fuel problems can also cause airflow dips, the turbo will give less boost if the exhaust gas cools due to a drop in fuel injection, and this will also be a very rapid change. But you would usually feel the drop in power if this happened.

A bit of my latest Forscan run is below.

(The light blue line in g/sec is MAF, FRT is fuel rail temperature, the green line is fuel rail pressure, APP is accelerator pedal)