Maf And Turbo

[mumof4]

No one actually answered my q so i guess ill just have to ask again :D

 

does having the maf disconnected affect the turbo or are they separate units?? :(

[Davetheref]

Actually, I dont know the answer. I just didn't want you to fell left out again.

[mumof4]

:( ;) :D

 

Cheers Dave. :(

[mumof4]

Oh..and when you replace the maf..do you have to replace anything else...like the pollen filter? :(

[tim-spam]

They are separate units, but one does affect the other via the ECU. The MAF basically measures the mass of air being drawn in by the engine (and this will be partially dependent upon the turbo), and is one of the factors that allows the ECU to calculate the appropriate fuelling and turbo vane setting. Other factors are the engine speed, accelerator position, water temperature, air temperature, etc.

The turbo is basically two turbines, one in the exhaust manifold that uses the flow of exhaust gases to cause it to spin, and the other (which is on the same shaft and therefore spins at the same speed) in the intake tract that forces air into the engine at well above atmospheric pressure. The turbo is responsible for these engines being able to produce such high power and torque.

Disconnecting the MAF will send the ECU into limp mode, drastically reducing the fuelling to the engine and the power output. The turbo will be affected in that the flow of exhaust gases will also be reduced.

[mumof4]

Ummm,,,......so..the maf being disconnected means the turbo does not work as well as it should,..if at all???and that less fuel goes thru the engine??? :(

[tim-spam]

Disconnecting the MAF will make the car feel as if the turbo is not working - you'll struggle to overtake cyclists and milk floats.

[Guest neil_wiles]

There is somewhere a huge descriptive document that I wrote that identifies what the MAF does and how it does it but a quick version of it is as follows.

 

The MAF (Mass Aif Flow) sensor measures the temperature and volume of air flowing into the manifold and from this the ECU (Engine Control Unit) calculates the amount of fuel required based on the flow the temperature the accelerator position and the engine speed. This in its own right would not affect the turbo actuator position but if the response of the ECU is to accelerate the engine then the vacuum assistance which governs the impellor position in the turbo is adjusted to give the required boost pressure in the manifold to increase the engine speed with the current load being applied (basically the turbo is turned up by the ECU if the require torque is not being applied).

 

Hope this helps but simply put all the engine performance systems rely on each other including the MAF, Turbo, EGR and ingition timing.

 

I think I need to lie down for a while now......

[mumof4]

your not the only one!! :(

 

whats the EGR??

[mumof4]

Disconnecting the MAF will make the car feel as if the turbo is not working - you'll struggle to overtake cyclists and milk floats.

 

 

I do feel like its not working but we can still overtake pedestrians and milk floats!!

the car can reach over 90mph..i havent gone over that yet..and i dont think hubby has as he hasnt got another ticket yet. :( :D

[marinabrid]

90 mph !! id say it was working ok.

[mumof4]

so turbo is working even tho dont feel like it is...even tho with the MAF disconnected it shouldnt really be working.i got that right have i???

 

 

You know the MAFS you can get off ebay....How would i know if i was buying the right one?...i know that in a previous post you have to make sure that the bit has those round thingies on the ends to make sure there is no chance of contamination, but im really unsure as i dont want t o fork out

[Bigjeeze]

so turbo is working even tho dont feel like it is...even tho with the MAF disconnected it shouldnt really be working.i got that right have i???

 

 

You know the MAFS you can get off ebay....How would i know if i was buying the right one?...i know that in a previous post you have to make sure that the bit has those round thingies on the ends to make sure there is no chance of contamination, but im really unsure as i dont want t o fork out

[mumof4]

yup..i think we need it as before it was disconnected we struggled up even a slight hill!!, it was also sluggish on acceleration,hubby said it had no "balls" :lol:

 

when it was disconnected we shot up a hill like a bat out of hell!! :lol:

 

GSF???????

 

having just spent

[dave_m]

GSF

 

Part Number 18788 AIR MASS METER SH Turbo Diesel >8/97

[Scorpiorefugee]

I cleaned my MAF with good results. I've described how to do it a couple of times but I can't remember where. Briefly, just remove the two screws on either side of the connction block and pull it out. You will need a security torx screwdiver set but they are freely available - I paid

[mumof4]

thanks for that scorp.ill give it a clean at the wkend as tomorrow im busy on test!!!!!!!!!

[graemer]

Hi,

 

I had trobule with my MAF but could not be sure at the time as disconnecting it made a big difference to performance so appeared to be OK. After checking other things like connections to turbo etc I decided to take the plunge and buy a new MAF from eBay - fantastic. The latest ones are a different design and I had my performance back - I soon realised that the car did lack oomph when overtaking at 50-60 and trying to accelerate up hills was poor. The final straw was being overtaken buy a gas munching 4x4 which before I had been able to pass with ease. Now performance is back...can't say this is your trouble but worth the money as it will fail ultimately, just a matter of time.