1989 190e 2.6 streight 6 running problems

[chris2405]

when not under load car will rev up fine but as soon as i start drivein it will only rev up to 3000-3200 revs in every gear... then just seems to die drop back down below 3000 revs and take off til it hits 3000 again, anyone have any ideas am compleatley lost on this on


thanks chris

 

[Stevie A]

I don't know for sure if your car has "limp home mode" which limits the revs but it would seem to be something like that which is causing revs to be limited in gear. Pay for a diagnostic test at a stealer or Merc specialist. I've read about this happening on other Mercs and it's limp home mode. It could be something else but not sure. It may be possible to reset if it is limp mode but I'm not sure how to do that on your car. On the newer models you disconnected the battery for a couple of hours.

If it's not limp mode there must be a fault in the rev circuit when in gear. Somebody else might have come across this type of fault and can shed some light on it.

 

[Ian B Walker]

Check your air filter. They have a habit of restricting revs.

 

[chris2405]

just replaced the air filter mate, if i cant get it sorted by the weekend its goin on to the machine, trying disconecting the battery tonight

 

[Stevie A]

Chris, I've been thinking about this and only other thing I can think of is a dirty sensor causing ECU to restrict revs when in gear. Your problem seems to be related to movement when in gear so try cleaning the air sensor that is in the air intake plastic bit near the right hand side of the radiator. It's easy to unplug it. Also try removing air filter cover and see if butterfly area is clean. Give that area a clean carefully. The butterfly can be pushed down by hand.

 

[chris2405]

will give it a try and let you no, thanks stevie

 

[star]

i had a car once that the wrong fuel pump relay was fitted and the rev limiter came in too soon.

 

[chris2405]

did it make the car jerk and slow down once it hit the limiter star

tried everythink else and nout worked

 

[star]

did it make the car jerk and slow down once it hit the limiter star

tried everythink else and nout worked

not so much jerk but the revs just bounced about the set limit, pull the relay out and it might have the number of cylinders on it or cross check the part number.

 

[chris2405]

still no further ahead with any of it, seems to run ok till its up to temp

 

[chris2405]

well had her into the garage, and apparently a gear box seal has gone, but they wouldn't tell me which one, apparently it is a common fault on theses mercs, do any of you guys no which one it is as i ain't paying Mercedes £120 an hour