Intermittent ignition problem Leon 1.6S '02

[mightywhelk]

Hello, my Leon has an ignition problem which is driving me mad and i'm hoping someone has the answer.

Every now and then when the car is started, the starter motor turns and the engine fires but chugs away on what sounds like a single cylinder. During this time, the battery and engine light are present on the display. You turn it off and try again and it doesn't fire at all, the starter motor just turns. Following this, there is a strong smell of petrol in the cabin. Usually, if the car is left for about 5 minutes, it starts without a problem.

This happens at least once every few days so I took it to the local main dealer who hooked it up but unfortunately the engine reported no errors whatsoever. The trouble is, because it only happens every so often, I can't guarantee it will misbehave whilst in the hands of a mechanic. I'm tearing my hair out - does anyone have any ideas? 2002 Standard Leon 1.6S with a new set of plugs a month ago (replaced as a possible solution which hasn't worked) and on it's third coil pack last replaced 2005.

Cheers
Scott

 

[Muttley]

74 Kilowatt engine, code AKL? Your mention of a single coil pack indicates this, the 77kW engines have individual packs.

Have the plug leads been changed? They deteriorate over time, the insulation breaks down, and poor starting is one symptom.

Check the low voltage connector at the coil pack, unlikely to be the issue but poor contact here could be giving you grief.

Coolant temperature sender is often mentioned as a cause for many ills on the petrol Leons. It is relatively cheap to replace, about £30 for the part.

Cleaning and realigning the throttle body may also help. Realigning needs a dealer or someone with VAG-com.

 

[mightywhelk]

It went to the main dealer today and once again, the engine reported no errors despite not starting until the 4th attempt this morning. But, they did concede that the coolant temperature sensor is sometimes to blame for problems like this, just like you suggested so they replaced it. I hope it fixes the issue before it becomes expensive!

Thanks for your reply, at least i didn't sound like a complete buffoon when I spoke to them!
Scott

 

[mightywhelk]

Should anyone stumble upon this thread who is having a similar problem, get the coolant temperature sensor changed first as it seems to have cured my issue and the car is starting first time every time.

Scott