Over boost please help

[John B]

Hi need some help again sorry , When I give the terrano some heavy right foot up hills in a gear which may be a bit too high she seems to go into limp mode so I have to turn off engine then restart. I've been to see a local me mechanic and he seems to think its over boost as she is giving a lot of black smoke on high revs and the arm on the turbo isn't moving as it should at about 10mm on max revs. Also I've noticed that if I unplug the mass air flow meter it doesn't change the running of the car. Should it ? Any ideas chaps :thumbs

 

[solarman216]

you will never see the lever on the turbo move unless you are on a rolling road, offload the turbo just does not develop enough pressure, if unplugging the maf makes no difference then sounds like the maf is bad as with it not connected it should run like a bag of bones, Rick

 

[John B]

Thankyou but could a bad maf give me my problem ?

 

[solarman216]

Thankyou but could a bad maf give me my problem ?

definitely, you could try cleaning it, there are two fine ceramic rods with wire wrapped round, if you remove it and look at the down stream side of the wires you will see what they should look like, I expect the up stream side will be covered in black, clean this off very gently with a cotton bud dipped in meths or alcohol, or if you have it spray switch cleaner, if cleaning makes no difference then replace it, Rick

 

[John B]

Hi again, I took the maf off and could not see any wires to clean so i
Removed the two screws and pulled the main shaft out but couldn't see any wires to clean apart from two little prongs. Should Hesse have a wire going between them as I've put it all back together and it's still the same after a good clean. I took some photos and am going to try and upload them. Thanks again. John

 

[solarman216]

what model T2 do you have? Rick

 

[solarman216]

Bosch or Hitachi maf the Bosch is supposed to be self cleaning I guess it does this by heating the coil, but doubtful if this will work long term, I can post a pic of the Hitachi maf if need be, Rick

 

[John B]

Bosch or Hitachi maf the Bosch is supposed to be self cleaning I guess it does this by heating the coil, but doubtful if this will work long term, I can post a pic of the Hitachi maf if need be, Rick

It's a 2004 R20 And the Bosch number is 0281002596. I've just had a look on google and found a pic but mine is missing the wire as shown in pic with some sort of chip in the middle ?????

 

[solarman216]

OK sorry I will opt out as I only go up to 99, Rick

 

[TONUP]

Are you trying to look at the MAF with it still in the section that joins to the air filter?

If you are then you will need to remove the actual MAF component, which requires some Torx type drivers, or you can get onto the shoulder of the screws with a good pair of needle nose pliers.

Once removed you will definitely be able to see the two very fine wires. If you can't then it's faulty.

I used spray switch cleaner from Maplins to clean mine, and was careful not touch the wires with my fingers.

Please ignore this with my apologies if you have removed it as above.

Regards

Alan

 

[John B]

Are you trying to look at the MAF with it still in the section that joins to the air filter?

If you are then you will need to remove the actual MAF component, which requires some Torx type drivers, or you can get onto the shoulder of the screws with a good pair of needle nose pliers.

Once removed you will definitely be able to see the two very fine wires. If you can't then it's faulty.

I used spray switch cleaner from Maplins to clean mine, and was careful not touch the wires with my fingers.

Please ignore this with my apologies if you have removed it as above.

Regards

Alan

Thanks for your help tonup yeah I have removed the part you just mentioned and all I can see is two short prongs which look like should have a wire in between them as I've just found a pic on google and the new maf has this wire in question with some sort of chip. If that's the case which I think it is where the hell has mine gone ???? :thumbs

 

[John B]

OK sorry I will opt out as I only go up to 99, Rick

Ok Rick thanks for your help. John :thumbs

 

[TONUP]

It looks like you could start by replacing the MAF to try to sort out your problem then.

In previous threads on the subject of replacing MAF's there has been some problems with cheap pattern parts off of eBay etc.

Regards

Alan

 

[John B]

I'll most prob try and get a genuine one as like you said the cheap one's are shit. Thanks again for your time.

 

[John B]

 

[John B]

View attachment 4347

Please take no notice of this as I'm learning how to upload pictures :doh

 

[96terrano]

Please take no notice of this as I'm learning how to upload pictures :doh

It's not hard, you'll soon learn how to do it and then 'clutch' onto the information:lol

 

[John B]

View attachment 4347

It's not hard, you'll soon learn how to do it and then 'clutch' onto the information:lol

Lol. love it :lol:bow

 

[trophymick]

I thought you were clutching at straws? :augie

 

[John B]

:clap:thumbs

I thought you were clutching at straws? :augie

Love it