1994 W124 320 auto engine surging/cutting out

[whibb8]

I think the following problems are linked :-

When at standstill at a junction (in drive with foot on the brake) the engine surges very slightly and if I feather the accelerator to move off the engine will cut out. If I put my foot down firmly then I avoid cutting out although there is still a slight hesitation as if is about to stall.

When in reverse and I use the accelerator gently the car will respond as if I have floored it! If allowed to reverse under its own steam then there is no problem.

The air mass meter has been changed and the air inlet manifold has been stripped down with no apparent signs of a leak.

Any suggestions?

Thanks

Daz

 

[television]

Hi Daz and welcome, hope fully some answers in daylight

 

[jibcl500]

Did you replace the air mass meter for an original direct replacement or did you buy a cheap meter from GSF or euro or ebay??

If you went for the cheap alternative then you need to replace it again with the correct part.

jib

 

[kth286]

whibb8

Have you had the codes read ? What codes came up ?????

There are 3 important items to maintain on this engine configeration as follows:-

1. Lambda probe in exhaust needs to be changed as a maintenance item.

2. the coolant sensor in the cylinder head will often go out of spec.

Both the above are key in the feedback loop for accurate fuelling.

3. In addition to above, the charcoal filter in the wing needs to be changed as a maintenance item or it can get blocked.

 

[MotardMan]

I also found that a degraded vac line that runs from the inlet manifold, RHS of the engine as you look in the bay, to the front cover of the engine, can cause the exact same symptoms. Remove the plastic cover from the front of the engine, and disconnect the vac pipe. Does it make any difference to tick over? If not, then you need to check the connections. If you are lucky then a smear of petroleum jelly on the pipe connections will sort the issue for you. I had to replace the vacuum line, but it was an easy job.

HTH.