1998 Renault Megane

check for spark and check you are getting fuel !

[quote:c5cb531e79="Dave H"]check for spark and check you are getting fuel ![/quote:c5cb531e79]

everything works except i dont get spark fit new
tdc sencor and cammshaft sencor still wont start

you need to check you are getting power from PCM to coils ??

[quote:6bad568158="Dave H"]you need to check you are getting power from PCM to coils ??[/quote:6bad568158]

I am sorry to be so ignorent what is PCM stands for

sorry my fault, i should explain better ... the PCM (powertrain control module) or vehicles computer .. gets readings from the senors you have replaced then calculates the correct time to fire the coils/plugs based on the different readings from the sensors .. so if you have replaced the sensors and the wiring is all in good order, the next step is to check that the PCM (computer) is sending a pulsed (intermittent) electrical signal to the coils to fire the plugs !! do you have a manual for the vehicle ? i do not have any diagrams as the renault series of vehicles was not released in the USA .. your local library should be able to lend you a manual !

[quote:7541b95d25="Dave H"]sorry my fault, i should explain better ... the PCM (powertrain control module) or vehicles computer .. gets readings from the senors you have replaced then calculates the correct time to fire the coils/plugs based on the different readings from the sensors .. so if you have replaced the sensors and the wiring is all in good order, the next step is to check that the PCM (computer) is sending a pulsed (intermittent) electrical signal to the coils to fire the plugs !! do you have a manual for the vehicle ? i do not have any diagrams as the renault series of vehicles was not released in the USA .. your local library should be able to lend you a manual ![/quote:7541b95d25]

Hi
the PCM is not sending electrical signal to the coils
i have not changed the knock sensor could be this
causing the problem?
Renault garage told me the need to rewire the engine cost £700 crazy i dont belive this.
could be the ECU Unit? and not the wiring

the PCM and ECU are the same thing ..sorry .. it could well be the ECU has gone faulty and needs replacing .. but this will cost just as much as renault rewiring ? .. the knock sensor would generally supply a fault code regarding a fault that lies somewhere else rather than stop the engine from starting ? .. there must be a common fault here if renault are telling you it needs rewiring and not a replacement of the ECU ?

[quote:11fb861205="Dave H"]the PCM and ECU are the same thing ..sorry .. it could well be the ECU has gone faulty and needs replacing .. but this will cost just as much as renault rewiring ? .. the knock sensor would generally supply a fault code regarding a fault that lies somewhere else rather than stop the engine from starting ? .. there must be a common fault here if renault are telling you it needs rewiring and not a replacement of the ECU ?[/quote:11fb861205]

good question They said they can’t guarantee even after rewiring, so will cost me £700 pounds and still no start, it happens with the sensor the told me faulty
Camshaft sensor , replaced , paid and still don’t work so I took the car back home, can I check the
Wires my self ? any suggestion were to go from here
Thanks

When you say you replaced the TDC sensor .. do you mean the CKP (crankshaft position sensor) as well as the camshaft sensor ?... also do you have a manual for the vehicle .. check with your local library if they have one to lend ??

[quote:80a1b10682="Dave H"]When you say you replaced the TDC sensor .. do you mean the CKP (crankshaft position sensor) as well as the camshaft sensor ?... also do you have a manual for the vehicle .. check with your local library if they have one to lend ??[/quote:80a1b10682]

Hi
yes i mean both, crankshaft speed position sensor, and camshaft sensor have been replaced, I do have a Haynes
manual, i took the conecter of the ecu i checked the conector only one wire has power with out the ignition on should this be like this? i dont know what else to check unless is the ecu unit they is a website cheking and repairing ecu for 110 pounds plus parts
is calld the ecu doctor have a look the website and se what you think www.the-ecu-doctor.co.uk/

So to recap .. you are getting no spark and the ECU is not giving any codes ? renault say rewire ?

Firstly how did you check for spark ...secondly which type of coil do you have .. coil pack or coil on each plug ? we need to locate/trace the wire going from the ECU to the coil .. this wire should be getting a pulsed (intermittent) 12volts @ cranking .. if you are not getting this pulsed signal from the ECU .. then either the CAM/CRANK sensor are not sending the signal to the ECU .. or the ECU is bad and needs replacing or repairing .. your manual should supply which wire is from ECU to coils ... use a voltmeter to test you are getting this pulsed signal !! be careful you do not get a shock ...let me know

[quote:ca5d3c9113="Dave H"]So to recap .. you are getting no spark and the ECU is not giving any codes ? renault say rewire ?

Firstly how did you check for spark ...secondly which type of coil do you have .. coil pack or coil on each plug ? we need to locate/trace the wire going from the ECU to the coil .. this wire should be getting a pulsed (intermittent) 12volts @ cranking .. if you are not getting this pulsed signal from the ECU .. then either the CAM/CRANK sensor are not sending the signal to the ECU .. or the ECU is bad and needs replacing or repairing .. your manual should supply which wire is from ECU to coils ... use a voltmeter to test you are getting this pulsed signal !! be careful
you do not get a shock ...let me know[/quote:ca5d3c9113]

Hi
I took the car to a different Renault garage to find out that it was just the fuse that was broken (cost 0.72 pence!) The other Renault garage charged me £95 to replace the camshaft sensor, which obviously made no difference, after which they said the engine would need rewiring and quoted me £700 for this work!

Many thanks for all the time and suggestions over the past week, I can’t believe it turned out to just be a fuse, although through following all your advise I’ve learnt a lot more about the electrics in the car!

No problem ... anytime we can be of assistance in the future please feel free to log in .. also feel free to leave feedback using the link at the top of this reply and also spread the word of our website to your friends, family and colleagues ...

Happy motoring
Dave H