Its doing my head in!

[mike65]

Starting my 190e 2.0 ltr...

Its not quite right and the nature of the problem is maddening. The car won't start first time relaibly, it will start on the T of turn sometimes but other times it'll require 2 or three turns. The ambient conditons can make a differnce but not always. Yesterday at 6.30 am (quite cool) it had to be cranked breifly twice. Today at 9.30 am (warmer) it started perfectly. As it did at 3.pm in mild temp. Usually its better in cooler condtions indeed during winter it was'nt a problem at all.

When it starts badly the revs will wander for a few moments from 600-900 rpm them settle as the engine gains some heat after which point its fine.

On the Air Intake Bady there is a vacum inlet which sits behind the inake itself, you'd hardly notice it. With the vacum open starting is easier but the gear changes are a bit jerky and the engine not as smooth, with the vacum is closed (as it should be on a manual) starting is very hard esp in warm and car is tricky to drive smoothly until engine warms up.

I took the car to have the electrics of the Bosch system checked over
nothing is wrong they said. If so, is it the Cold Start Valve thats most likely at fault?

Help!

Mike.

 

[Adam_Beighton]

Don't know if this is any help, but have a look at post from bluefish posted in General Questions on 25 June 2004 :|

 

[mike65]

Yeah I followed that thread at the time but the symptoms are not quite the same...at least mine does start without too much trouble, I could live with it but I have the feeling I might need to replace one component and it'll be fine. Question is which bit!

Mike.

 

[Spike]

Seems symptomatic of a knackered OVP relay or its fuse.

 

[Wisher]

don't know if this will be of any help..

My car was the same, with not starting when the engine was cold, or when the engine was hot.... or wandering up and down the rpms
they found that....

1)- the fuel mix wasn't quite right. and that I had to get checked and put right every 6 months...
2)- the automatic choke wasn't working every time...

I'm trying to remember what else it could be.....

 

[mike65]

Okay I just unhooked the black box ECU and it started just fine. Does this mean its not working? Or not relevent?

Seems symptomatic of a knackered OVP relay or its fuse.

The fuse is fine...how does one test a relay?

edit> I just had a look at the relay and it was'nt properly connected by its pins (the plug lead is damned short) I shoved it back in after cleaning it. Started fine but it'll be tomorrow before I drive it anywhere...I've been googling and it seems they all fail at some point.

Mike.

 

[Spike]

Sounds like you may have just located the problem but to test the OVP relay:-

1. Remove OVP relay
2. Use approved multimeter. Set to diode testing
3. connect (+) testing probe to terminal 31
4. connect (-) testing probe to terminal 30
5. nominal value is 0.4V to 1.5V
6. if nominal value is not attained, check 10A fuse or replace OVP

 

[mike65]

For anyone having similair troubles - this is from a US spec 2.3 but they look the same (but does this one have two fuses?)

Mike.

 

[mike65]

I've just tested the OVP and I get a reading of between 400 and 1500 its never actually stabilises at a number but remains within that range. So is it okay?

Mike.

 

[NormanB]

Sounds like you may have just located the problem but to test the OVP relay:-

1. Remove OVP relay
2. Use approved multimeter. Set to diode testing
3. connect (+) testing probe to terminal 31
4. connect (-) testing probe to terminal 30
5. nominal value is 0.4V to 1.5V
6. if nominal value is not attained, check 10A fuse or replace OVP

Thanks Spike - most useful.

NormanB

 

[NormanB]

Okay I just unhooked the black box ECU and it started just fine. Does this mean its not working? Or not relevent?

Seems symptomatic of a knackered OVP relay or its fuse.

The fuse is fine...how does one test a relay?

edit> I just had a look at the relay and it was'nt properly connected by its pins (the plug lead is damned short) I shoved it back in after cleaning it. Started fine but it'll be tomorrow before I drive it anywhere...I've been googling and it seems they all fail at some point.

Mike.

Mike - give it a couple of days to see how it goes if it still plays up then I would replace I think they are £40 or so.

Let us know how this progresses please.

Best of Luck

NormanB

 

[mike65]

Bumpity bump. Spike are my readings okay?

While continuing my hunt for the source of the problem I wiped round the inside of the air intake valve beneath the flap and fetched out a layer of what can only be called soot! Which suggests rich running, so that suggests fuel/air mix which was done only late last year.

Would a bad cold start injector or sensor to same cause rich running? The same could account for the starting issues.

Mike.

 

[teky]

throttle body clean out and MAF/MAP sensor also idle air bypass valve

 

[mike65]

throttle body clean out and MAF/MAP sensor also idle air bypass valve

Wheres the MAP/MAF sensor, and idle air bypass valve located?

Mike.

 

[teky]

http://www.benzworld.org/publications/pub.asp?id=239
http://www.benzworld.org/publications/pub.asp?id=249
http://uk.msnusers.com/autodatabase/m.msnw

 

[mike65]

Thanks for the links, can't spot idle air-bypass valve is it there or just called something else in Bosch-World.

Mike.

 

[mike65]

Browsing for something else I spooted this thread, just to add that the problem turned out to be a failed water temp sonsor.

Mike.