98 Megane Intermittent Starting Problem

[pjs2388]

Hi, wonder if anybody had any ideas on this starting problem?

My car is a 1998 Megane 1.4 litre petrol engine. Now and again, (maybe once in every 10-15 times) the car will not start. It turns over but does not fire up.
Sometimes just holding the ignition key turned for an extra 5 or 6 more seconds gets the car going or more often I have to sit and wait about a minute before trying again and then it will normally start staright away.
This happens in both cold or warm conditions, dry or wet, and when the car has been sitting overnight or jsut turned off for a couple of minutes. There seems to be no pattern to it.
I should add that once the car has started I never have any further problems while idling or driving.

I had a very similar problem about a year ago which we eventually diagnosed as a problem with the distributor cap and rotor arm (which were badly pitted and worn). These were replaced then but they look fine to me now, so I think I can rule them out.

Thanks for any help.

[kev2407]

Hi i had this problem with my 1.6 1998 r reg megane it drove me crazy till i took some advice from a mechanic at renault. His advice was to change the TDC sensor (top dead centre) he said the price of this sensor was £26 plus £35 for the wiring loom (these must be replaced as a pair as the new sensor doesnt fit the old plug) which i thought was ok until he told me that it was difficult to fit the cable loom as it went all the way to the back of the engine then into the ECU. He quoted the job at around £200 for the labour however the advice he gave me was excellent he said to removed the sensor and check for carbon on it as this was a very common fault if i found any carbon to remove it and refit the sensor. The sensor had a tiny bit of dirt/carbon on it which i didnt think would make a difference but it did and the fault never returned. It is very easy to remove it has an electrical plug and is held in by two 10mm bolts but be very careful not to drop the bolts as they go straight down into the gearbox if you drop them because that is where the sensor is above. The sensor is on the passenger side of the engine as you look at the car (or at least that is where it is fitted on the 1.6 model) and it is shaped like a bannana it is about an inch long hope this helps.

[pjs2388]

Thanks for your reply and sorry for the delay in getting back to you!!

I found the sensor from your instructions and cleaned it up (quite a lot of dirt came off onto the rag!!).
It's been 2 weeks now and I have had no further trouble with the car starting.
Excellent piece of advice
Thanks again, saved me a lot of money.