190E 1.8 Automatic erratic idle speed?

[christiankay]

I've had a look through the threads but unable to find someone experiencing a similar problem. My 1990 (H) 190E 1.8 Auto VIN No. WDB2010182F775169 has developed an erratic idle slowly hunting between 500rpm and 800rpm when at a standstill. Worse, it seems when I brake to a standstill or change between Park, Reverse and Drive the engine feels like its about to stall (so far it hasn't actually stalled).

My car has always loved starting from cold with the auto choke kicking in strongly but hates starting from warm (feels very lethargic on the ignition and needs a good rev). The ATF was changed in 2006 at Parkway, Bristol.

If it does need to go to a garage what do I tell them without sounding like a complete amateur?

Any help will be greatly appreciated. Thanks

 

[television]

When an engine is hunting, this is 95% of the time an air leak in one of the vacuum pipes or a leak in the inlet manifold somewhere.

At idle the vacuum is at its max, the engine takes in air from the leak, and speeds up, the vacuum goes down as the speed increases and then sucks in air again from the leak and it speeds up, and so the cycle goes on.


Make sure that all of the pipes in the link are tight and no pipes split.

Indoor fish shops are an ideal place to buy pipe from

http://www.detali.ru/cat/oem_mb2.as...GM=717.412&CT=F&cat=14R&SID=80&SGR=015&SGN=01

 

[phil_2413]

Quick question please Malcom if you read this, you say a leak in the vacuum pipes or inlet manifold could cause the hunting, could it also be causing the difficulty starting when warm? I have the same issues as Christian from time to time.

Thanks,

Phil.

 

[television]

The vacuum could cause the poor warm start, but low on the list. A pressure check is always advised to do first

things that are

Aux air valve
Airflow plate position
Airflow plate or plunger
control pressure warm

 

[christiankay]

Hi eveyone thanks for reading and helping.

My car starts from cold strongly like a new car - idles perfectly in P (Park) select D for drive and away I go no problem. Crusing up to traffic lights as the revs fall suddenly the car feels like it wants to stall but can't. The rev needle bounces off the 0 rpm and struggles back up to around 500-750rpm. I don't use P at junctions really and just hold the car on the brake. Idle returns to normal and off I go no trouble.

Worse - as I'm stopping (tries to stall) go from D through N to Reverse and the revs dive and it tries to stall. Finish manouvre and every time i select while holding the car on the brake the engine is trying to stall (it actually did last November). Normal driving is fine just stopping and engaging the selector.

Warm starts not so strong or great but she manages it ok just can take a few attempts.

I'm unemployed so getting my car repaired and serviced is a constant struggle both financially and stress wise. I always get ripped off by garages whoever they are Merc specialist, main dealer, rapid fit centre, local garage, Bosch specialist ... nobody wants to quote or stick to labour rates.

I'm not an expert - I have this forum, my army mechanic brother and my trusty Haynes manual but garages are a nightmare - maybe it's me. The minute they get a whif that I have no idea whats wrong wity my car I see £££ in their eyes. Now i know how my mum and sister feel when dealing with garages.

 

[redlaser]

Stalling at lights

Sounds like the fuel pump relay..I had exactly the same symptoms and after changing the FPR..no more stalling.