have to go fast to keep it working??? HELP

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kie010

New Member
Joined
Apr 4, 2014
Messages
12
Car
ml270 cdi 2002
Well where to start I have a Ml270 bought it off my mother in law she was driving in limp mode for 5 months. I found a possible cause the fuse hidden away behind fuse box was blown replaced it. Coolant light went off and heated seats started working again. Car started and turbo engaged. Thought it had fixed but then went limp limited to 3k revs, replaced maf I didn't use a pierberg or anything just an unbranded one, still tan the same.
Now this is where it gets confusing. When started in morning it runs as it should heats up a bit and limps again. Now if I turn off and on rev it it will be fine I can go for miles if I floor it and keep the power going occasionally, come to traffic and it will limp again its great when it run but I can't drive everywhere at 2.5k revs willl soon get a few speeding tickets
I am going to have it in a star on Tuesday but if anyone knows anything and could save a few pennies that would be nice
Thanks all
 
Did have it out and cleaned it maybe need a proper soak, would I be able to move internals myself to check movability
 
The EGR valve is monitored by the MAF sensor. Ensure a voltage drop of ~0.4v is being seen when it is operating.
 
I have great mechanical knowledge but useless with electrics I have a multimeter how can I check this and solution if < or >. ?
 
On the MAF, Pin-5 WRT Gnd.

If you unplug the EGR vacuum pipe the valve should close.
 
UPDATE. had egr Off again cleaned again, made piston move by pressing from cooler port with a bar and moved up a lot of resistance from spring, put all back together, started up still only 3k revs so turned it off then back on with some revs, fine for a minute until left to idle then 3k revs again, took vacuum pipe off eye theres not a lot of suction there, also when I rev it when revs are dying down it sounds like it is sucking in air from near filter on back of turbo, would cleaning or replacing said filter be any good?
 
On the MAF, Pin-5 WRT Gnd.

If you unplug the EGR vacuum pipe the valve should close.

He means measure the voltage on Pin 5 of the MAF with respect to ground. I.e. measure the voltage on Pin 5 to ground (battery negative). You should be seeing about 0.4V when the valve is operating. Make sure you set you meter to DC volts and in the correct range to show 0.4V.
 

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