More help needed please!

[reedybopper]

When I last posted, I had explained that I changed the battery on my W202, after which my car has now started to cut out when pulling upto junctions. This has now resulted in me driving with a heel and toe configureation. Once the car has warmed, it will tick over, but very erratically. from 100 - 1200rpm constant. The car performs well enough, but will cut out at junctions etc.. as i have just explained.

I was adviced to change/check the OVP Relay, I have just bought a second hand unit from MERCMAN, (and he assures me that the car it came off was running fine), but there is no difference! I was also advised to check the relay switch in the boot next to my battery, which I did, and all the contacts seem to be in perfect condition.

Can anyone offer any advice, my car is due in for MOT next weekend, and I feel this would not pass if will not tickover during CO2 test.

Many thanks in advance as I know you will respond.

Cheers

 

[recycled]

have you checked if you have got a gasket problem? also this sounds to me more like a combustion fault e.g air intake or auto choke.

 

[television]

The last one of these that had this awful hard to find fault had a spit in a vacuum pipe, and this would also fit into what recycled said

 

[jaymanek]

idle control valve?

 

[reedybopper]

The last one of these that had this awful hard to find fault had a spit in a vacuum pipe, and this would also fit into what recycled said

Where is the said vacuum pipe?

Andy

 

[television]

Where is the said vacuum pipe?

Andy

This car is Motronic , so no idle control valve, it s all done via the Main ECU
http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=80&SGR=015&SGN=01
Re vac pipes look for any splits, even pull off and re fit to see any change

 

[reedybopper]

This car is Motronic , so no idle control valve, it s all done via the Main ECU
http://www.detali.ru/cat/oem_mb2.as...417717.418&CT=F&cat=44V&SID=80&SGR=015&SGN=01
Re vac pipes look for any splits, even pull off and re fit to see any change

Don't like that sound 'ECU' Sounds expensive. I will try and look at the vacuum pipes when it is light tomorrow. Is it just a case of removing them and checking for any splits etc.. I will not have to re-seal the system or anything like that do I?

 

[television]

Ignore the ECU it was in answer to something else

Vac pipes go hard and possible poor fit,, for normal checking they can be pulled off and your finger put over the end of the pipe or from where it connects

Nothing to seal this pipe can be bought from any indoor fish tank shops,and is very cheap.

I think that the battery change is /was a red herring on this

 

[reedybopper]

Ignore the ECU it was in answer to something else

Vac pipes go hard and possible poor fit,, for normal checking they can be pulled off and your finger put over the end of the pipe or from where it connects

Nothing to seal this pipe can be bought from any indoor fish tank shops,and is very cheap.

I think that the battery change is /was a red herring on this

I take it that this would be ok to test these pipes whilst car is running, in order to check vacuum is working etc..?

 

[television]

I take it that this would be ok to test these pipes whilst car is running, in order to check vacuum is working etc..?

Much easier when the engine is running, thats if you can keep it running.

If you pull a pipe off, with little change to the engine running,, by putting you finger over the pipe or the fixing tube see if anything gets better or worse. Often just running your fingers up and down the pipes will provoke a change in the running

 

[reedybopper]

Much easier when the engine is running, thats if you can keep it running.

If you pull a pipe off, with little change to the engine running,, by putting you finger over the pipe or the fixing tube see if anything gets better or worse. Often just running your fingers up and down the pipes will provoke a change in the running

I will try this tomorrow and get back to you all.

thanks again Malcolm.

 

[television]

I will try this tomorrow and get back to you all.

thanks again Malcolm.

It is not to hard to check on these pipes,, but they do have to be checked before moving on.

I am going to buy some Motronic books,, there is a greater understanding needed on the forum

 

[reedybopper]

Hopefully I may have sorted it, I have included a photo, tell me what you think?

When I remove the pipe (arrowed blue) the car seems to run better not cutting out a junctions etc.. But when I remove the pipe (arrowed red) the car does not change, revs change for a bit, then goes back to doing what it has been doing.

Now I know what you are going to say." the two pipes are conected" but whaen they are removed individually they behave different? When I do remove any of the pipes, you can hear loud sucking noises from the pipes, presumably this is the vacuum.

Your thoughts please..

Andy

 

[reedybopper]

Photo

When I last posted, I had explained that I changed the battery on my W202, after which my car has now started to cut out when pulling upto junctions. This has now resulted in me driving with a heel and toe configureation. Once the car has warmed, it will tick over, but very erratically. from 100 - 1200rpm constant. The car performs well enough, but will cut out at junctions etc.. as i have just explained.

I was adviced to change/check the OVP Relay, I have just bought a second hand unit from MERCMAN, (and he assures me that the car it came off was running fine), but there is no difference! I was also advised to check the relay switch in the boot next to my battery, which I did, and all the contacts seem to be in perfect condition.

Can anyone offer any advice, my car is due in for MOT next weekend, and I feel this would not pass if will not tickover during CO2 test.

Many thanks in advance as I know you will respond.

Cheers

 

[reedybopper]

Photo

Sorry forgot to put the photo on.

Hopefully I may have sorted it, I have included a photo, tell me what you think?

When I remove the pipe (arrowed blue) the car seems to run better not cutting out a junctions etc.. But when I remove the pipe (arrowed red) the car does not change, revs change for a bit, then goes back to doing what it has been doing.

Now I know what you are going to say." the two pipes are conected" but whaen they are removed individually they behave different? When I do remove any of the pipes, you can hear loud sucking noises from the pipes, presumably this is the vacuum.

Your thoughts please..

Andy

 

[grober]

The unit the blue arrow is pointing to is the fuel rail pressure regulator. This sets the fuel pressure to the injectors by a fuel return spring to between 2.5-3 bar. The setting and thus fuel pressure is modified by a diaphragm whose position depends on the inlet manifold vacuum downstream of the throttle plate- hence the connecting pipe. The idea is to maintain a fixed pressure drop across the injectors independent of the throttle plate position. Without the vacuum from the manifold to open the return valve and cause a drop in fuel pressure the car will run richer with the throttle plate closed. This suggests an air leak in the manifold and associated pipework as has been said already. You could try removing a couple of spark plugs and check for a weak mixture. Other possibilities are with the MAF or lambda sensor affecting mixture control.

 

[television]

I have been away,,,not all 202 1996 have a MAF

 

[reedybopper]

I have been away,,,not all 202 1996 have a MAF

I agree, I have read many posts on this forum about the MAF, and i have yet to find one on my car!

 

[grober]

If you have the PMS system make sure the manifold pressure sensing pipe to the ECU isn't leaking or partially blocked. Idling problems can also be caused by a faulty throttle plate position sensor/switch or dirty injectors.