Weird Gearbox snag

[mercman1969]

W163 on a 52 plate

I am still getting an intermittant fault regarding kickdown
it appears to be when under load....on hills - even very shallow ones

at times even when depressing the switch under the pedal the car simply doesnt kickdown

sometimes if you back right off the throttle and then try again it will kickdown....other times it wont

my thoughts are

Throttle Position?
Gearbox fault?

What would cause such.....would a faulty MAF cause this?

 

[Buggerlugs]

Possibly a MAF fault, but in these circumstances the only way to prove it is to swap it for a new one and see what happens.

I would road test with the Star hooked up and monitor the live data to try and get an overview on what's occuring, that's all I can say right now, unless you wanna take the dealer approach and keep firing parts at it till it's fixed........."That'll be five large please sir...."

 

[mercman1969]

Nearest person to me with a STAR then please

I am in Grantham...Lincs

Have thrown enough money at this already

 

[jrggino]

[Hi I have had a sililar problem on my 1999 e300 td where i lost kickdown and it was very intermitant. I noticed it more if i was doing over 90mph for long distances. I was very unsure but was given details on how to check the maf by dieselman. very helpfull person. I checked it and it was not within spec so i have changed my maf. at the moment all seems ok also noticed a better driving car.
Gino i dont have the spec to check on me ask dieselman]Nearest person to me with a STAR then please
Gino
I am in Grantham...Lincs

Have thrown enough money at this already[/quote]

 

[Buggerlugs]

Hi Mercman,

The nearest competent tech I know with a Star is in Mansfield, which is about 40 miles from you, so might be a touch too far, but if you get stuck call Milan @ RM Motors on 01623 810585. HTH.

 

[Dieselman]

The MAF can be tested with a voltmeter. On Pin5 expect ~2v at idle rising to ~4.8 at full revs.

If it's faulty it will usually read low.

 

[mercman1969]

Anybody got a schematic of the plug....which is pin 5?

I assume any earth will do for the other probe