1990 260E (W124):
After kickdown, sometimes the engine are slowing down and hesitating, it has no power at all. Only the economy-meter are changing when I gives more pedal.
The enine gets stalled / strangled in a way.
If I use kickdown one more time, it goes like normal and I get full power, but when i slow down again - it hesitates and just don't want to run properly.

After about 10 sec, the engine are just fine again and can be fine for very many miles and several kickdowns.
Everything are normal in the meantime.

It seems like the engine gets enough fuel, because it goes like hell with full power at kickdown. This happens when or after I slow down.

Hope some of you have a possible solution for this.


Sorry for bad english.


Grunde

Check your fuel pump relay. some soldering may be broken.

How can I check fuel-pump relay?

Can the OVP relay cause such behavior?
What about the ignition?

It happens only at rare intervals.
Between the problems (which last only for some seconds) everything is OK.


Grunde

Sorry to have been able to reply earlier,

I should have added to my first post to make a search with "fuel pump relay".

Some one said , I do not remember who it was, that he had a small wire to connect two pins on the relay connector ( I believe 30 and 87).

But it may be some thing else also. There have been a lot of discussions on this topic.

Thank you for your help.

I thought that a bad fuel-pump relay would cut off the fuel and cause the engine to stop completely. Or am I wrong?

My engine don't stop, but gets a extreme hesitation or loss of power.


Grunde

I had the same thing on my 260E, 1988.

I changed o lot of modules and nothing worked, until I opened the relay and saw several soldering which were broken by fatigue.
Some one else found the same thing as me.

It could well be something else at least bypassing the realy could help to identify if the problem is created by him.

please make a search on the same topic there is a lot of discussion.