damn!!!

fitted the new MAF sensor and the EGR valve has been cleaned but she still aint right

1) disconnect the MAF sensor power good at low revs not much power after about 3200 rpm

2) reconnect the MAf sensor loads of power after 2500 right up to 4500 but not much power below 2500 rpm

EGR valve has been cleaned, maybe i should replace it?

frustrating!!!!!!!!!!!!!!!!!!!!!

T14086 said:

Here lies a problem...symptons of faulty air flow meter & EGR are very identical (bad EGR doesn't always mean black smoke) so its often guesswork which can be expensive.

Click to expand...

Sometimes its best to get it diagnosed correctly,as far as cleaning EGR's I wouldn't personally,they are only £70.

Snatch 69,

You are going through a very similar diagnostic nightmare to the one I went through. Problem is the more you change things the more chance you have of introducing a new fault. On the basis of my experience I would return the MAF to its original state and blank the EGR to prove if this is at fault or not. You can search for other threads for information on this. Cleaning my EGR would not have been enough. I needed to dismantle and free the actuating solenoid. Something I only found by chance.

The solenoid on my EGR valve seemed to have been effected by corrosion from exhaust gases. It was very stuck. When I looked at the EGR it looked to me that in either its open or closed position the valve presented a seal for the passage of gases into the solenoid. Assuming that the valve is not stuck this would mean that exhaust gases could only get to the solenoid for a fraction of a second while the valve is in motion. I assumed that the valve was normally either open or closed and that was all, meaning that once it stuck partly open gasses would reach the solenoid and ensure that it would never move again!

T14086 has said that the valve is modulating which would seem to blow this theory out of the water. He has far greater knowledge than me but it would be interesting to understand how the valve was designed to work. There is obviously a weak point in the design

OldBo