Poor start/Idle megane 1.5 dci

[davidnaud]

Hi i am pulling out my hair over this so many people saying different things.I have had the car a month now i fell for it because the air con was turned on just didnt realise until now how it happened.The car will usually not start first push of the button but if it dont it will on the second but seems as if there wont be enough battery power to do it but it does start to which the engine managment light comes on and so does the service light.The idle is terrible shaking like mad but once you press the air con button it stops as soon as the compressor kicks in i plan to take the family on holiday soon and dont want it to die can some one help i have also replaced the fuel and air filters and cleaned the egr valve

[Taters]

David

Is this from a cold engine or warm engine?

Do you have any smoke coming out of the exhaust? Is so what colour?

I'm guessing the slight increase in revs from the aircon kicking in is helping the tickover or I do believe the EGR valve system shuts off when aircon on.

[AlexB]

davidnaud,

You need to tell us the history of this car. As you bought it second hand, then most likely it was neglected, broken and serviced to the minimum specifications, i.e. badly.

Regardless of it, if the service light comes up, you need to have the OBD fault codes read.

It sops shaking with the aircon, because the engine management computer adds revs automatically when the aircon is on.

[davidnaud]

Thanks for your help i forgotten to mention when i came to clean the egr a while ago i realised the connector was not connected idle seemed better think it was my imagination.Today i decided to look at how difficult it is to remove and clean the cam sensor on the bell housing and realised the connector was also off this i connected back up and idle was near perfect i drove down the street and still got service lights on and managment light on and when i pulled back on the drive idle was erratic again i have disconnected the battery and ecu in an hour shortly i am going to connect it all back up and give it a try i would clean the cam sensor but i aint got a jack to undo the mount to get to it but if the problem isnt sorted im going to disconnect the egr and see if there is any difference i will let you know many thanks again

[davelowe]

Oh dear. I hate it when these types of posts appear for this reason: someone who owned the vehicle before you has botched things up to make it a runner. Now (assuming a private sale), you have to fix things, and have no recourse.

Alex summed it up in fewer words.

You will not solve the problem by disconnecting essential inputs to the ECU; this is what the previous owner did. Connect everything back together, then read the fault codes (either buy an ELM 327 - or pay a similar amount for your garage to do the same thing).

The reasons that cause the running issue are myriad. Pray it's something simple such as a dud battery.

[davidnaud]

I have also noticed the glow plug light has never came on since i have had it

[davidnaud]

what diagnostics kit am i best with cheaply i have seen the elm kits are they all pretty much the same?

[AlexB]

I have a blue-and-orange USB box, using it with a laptop running ScanMaster. My friend got a similar Bluetooth box; it works with Android phones as well as laptops. It is hard to say which one is better. Mine is used once a year, when servicing the cars.

[davidnaud]

thanks alex how much can you do with it can you reset codes and do global scans ?

[AlexB]

This is the prodict web page for ELM327 chip:
https://elmelectronics.com/obdic.html

You may see, it can do many things and supports all OBD protocols. However, it does not go beyond the standard, in the territory of the proprietary protocols. The same page also states that the version of the chip must be v1.3a. Everything above it is a fake. OBD only supports the engine, i.e. everything emissions-related. Brakes, airbags, etc. are not included. Yes, it can reset some faults, but only if the fault has been eliminated. Resetting a fault does not make your EGR valve cleaner!

These are the pages from Wikipedia, explaining what OBD is:
https://en.wikipedia.org/wiki/On-board_diagnostics
https://en.wikipedia.org/wiki/OBD-II_PIDs

This is a detailed review of Torque software:
https://www.youtube.com/watch?v=Ay-ZvTn3fLo

Scanmaster is a little more powerful, as it allows one to download the live data for further plotting. It is useful if one wants to discuss the problem on a forum.

[davidnaud]

GOT MYSELF A DIAGNOSTICS KIT codes are as follows but i need a point in the right direction the exact readings are p0340 camshaft position sensor "a" circuit is that the sensor on the cambelt housing? and could it just be a matter of cleaning up, the other is p0487 exhaust gas recirculation throttle position control circuit i am guessing this isnt the egr valve but i just dont know can anyone help thanks

[ikhan]

GOT MYSELF A DIAGNOSTICS KIT codes are as follows but i need a point in the right direction the exact readings are p0340 camshaft position sensor "a" circuit is that the sensor on the cambelt housing? and could it just be a matter of cleaning up, the other is p0487 exhaust gas recirculation throttle position control circuit i am guessing this isnt the egr valve but i just dont know can anyone help thanks

Bit of a catch-22 here - those codes could simply be thrown up as the cam sensor and egr were disconnected, or they may have been disconnected because the last owner had the same codes!

Try clearing the codes and see if they come back....

[jimbob005]

sorry to high jack this post but im thinking of getting a code reader but lookig on ebay i found some but they are saying megane 2 2005 i have an 2004 mk2 will it work?



https://www.ebay.co.uk/itm/OBD-II-CAN-Bl ... 6649wt_839

thank james

[davelowe]

Short answer is it might. The slightly longer answer is that it probably will give you the fault codes.

On my 2003 (and assuming up to 2006, possibly beyond) the protocols look right.

My 'experimental' 2008 tech run, is a different story (and long).

The link you posted looks suspicious. It is too good a price to be likely reliable. Try to find someone who imports these things from a local place. It's worth the mark up (and software discs) such that you can return it when it won't work.

Worth a try if you don't mind waiting 2 weeks for shipping. - let us know how you get on. For £30, a garage should be able to give you the codes, and you can google any that turn up. These should give you pointers.

[direstraits]

GOT MYSELF A DIAGNOSTICS KIT codes are as follows but i need a point in the right direction the exact readings are p0340 camshaft position sensor "a" circuit is that the sensor on the cambelt housing? and could it just be a matter of cleaning up, the other is p0487 exhaust gas recirculation throttle position control circuit i am guessing this isnt the egr valve but i just dont know can anyone help thanks

You need to reset the position for EGR valve, there is a command that is executed from Clip after cleaning or changing EGR valve. As for camshaft position sensor, if the car has problems with starting, it is probably a dead sensor, or loose connection or wiring.