TD6 Motor surge

[whitedog]

Hi All

Getting my rangie up tp scratch I have had in the last six months the intank fuel pump and inline fuel pump replaced. Plus injectors and just recently the fuel pressure regulator replaced all genuine parts.
I am experiencing slight surge in the motor when in drive or idle.
Fuel filter new.
Waiting for all the gurus to give me their thoughts.
The diagnostics were done when the fuel pressure regulator was replaced.

Cheers Denis

[Laurie]

Denis
Considering you have had the injectors done, Have you cleaned your MAF sensor ?

Laurie

[whitedog]

Hi Laurie

Once again I appreciate you answering. Mate I am a novice what is the MAF
sensor and where is it.

Denis

[Laurie]

Denis
You can buy a MAF spray cleaner from the auto shops; I use Electronic Circuit Board or Cleaning Solvent from Jaycar ! When you spray, just don't put too much pressure on the internal wire, they are delicate.

Laurie

[Hoges]

Hi Laurie

Once again I appreciate you answering. Mate I am a novice what is the MAF
sensor and where is it.

Denis

The MAF is a "Mass Air Flow" sensor. It is located in the large air intake tube between the air filter and the engine inlet. The sensor is a single (usually) wire attached to some clever circuitry. The sensor wire measures airflow into the engine, based on a change in the electrical resistance of the wire. On the basis that oxygen is about 20% of the airflow, the engine computer then takes this value to regulate how much fuel the injectors deliver on each stroke of the engine. Once the air-fuel mix has been burnt in the engine the exhaust gas is analysed by the oxygen sensors located in the exhaust pipes. The O2 sensors feed their readings back to the computer, which further fine tunes the fuel flow for the load, temperature etc. All of this analysis /fine tuning happens thousands of times a minute. That is why the MAF is so critical to proper engine function..

Hope this helps explain it

[rar110]

Denis You can buy a MAF spray cleaner from the auto shops; I use Electronic Circuit Board or Cleaning Solvent from Jaycar ! When you spray, just don't put too much pressure on the internal wire, they are delicate. Laurie

Is carby cleaner too aggressive?

[Laurie]

I think it would be too caustic for the fine wires ????

Laurie

[Hoges]

You need a solvent which leaves next to no residue. Depends what additives are in the carby cleaner. It's possibly OK... you could "test" it on a mirror and let it evaporate and see what's left. The pressure pack disc brake cleaner has been used to good effect by others and leaves very low residue... -test it on a mirror as well. If you have been up to date with air filter changes, the MAF should not be contaminated.

[whitedog]

Hello to all you good fellas

Very much appreciate all the info. Its Monday morning and I will attend to this and let you know how I go.
After having three discos previously I am on a steep learning curve with this vehicle. Thank goodness for this forum and the help I can get.

Cheers Denis

[whitedog]

Denis
You can buy a MAF spray cleaner from the auto shops; I use Electronic Circuit Board or Cleaning Solvent from Jaycar ! When you spray, just don't put too much pressure on the internal wire, they are delicate.

Laurie
Hi Laurie
Really appreciate your help. The PDF file was a great help, I was also surprised to see the Maf also affects the fuel engine cut off. I am now thinking could this be my 1 second run on when I turn off the key.
Best regards Denis

[rar110]

How did you go with this?

[whitedog]

thanks for all the input no luck fixing the problem yet but have spoken to a German mech who works on BMW he thinks it may be the injector pump.hope not but will keep posting the updates.

[rangietragic]

Mine was surging badly at idle after sitting for months waiting for new air struts.Fuel level was VERY low.Put some diesel and a bit of fuel conditioner in and took it for a couple of kays drive.Surge bareley noticeable now.PS,new struts should be here by Tuesday.

[whitedog]

Hi all my fellow readers finally I can give you the answers to all my fuel woes.
Firstly as you know I had the intank pump replaced only to find the inline pump working intermittently which I had replaced also when it gave up.
The next drama was the injectors had to be replaced. Then lo and behold I started to have the two second run on after the key was turned off. Then the surge or hunting began.
Finally found metal filings in the fuel pressure regulator screen and following through on this discovered the fuel injector pump was shot.
The car is now performing beautifully,the run on has gone which was connected to the woes of the pump.
I only bought the car 14 months ago with great excitement to have finally achieved my dream of owning a L322. I feel that the problems from beginning to end regarding fuel cannot be coincidental as the whole fuel system has now been replaced.
My wife feels strongly that this car must have had severe fuel contamination at some stage that has gone through it like a cancer.
I and my wife now live in hope that we have the car we always wanted.
I would like to say thank you to one and all that have tried to help over this period of frustration that is now hopefully at an end.
Many thanks
Denis