Mechanics

1.9DCI DIESEL - COLD STARTING PROBLEM

2002 Renault Laguna

Engine Mechanical problem
2002 Renault Laguna 4 cyl Two Wheel Drive Manual

Car doesn't start when cold, but does when warm.

I've had glow plugs replaced, a new battery and a new crankshaft sensor.

If I take off the air filter and squirt WD-40 in the intake, it helps to start the engine.

The car idles and drives fine - No loss of power and is averaging low 50's in the mpg so appears fine here too.

Any ideas? Apparently the fuel is getting to the fuel rail ok. Does this sound like a problem with the pressure regulator or the injectors? Any help would be great.

Michael
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Michael_cat_uk
April 12, 2010.




Replace the fuel filter. Check fuel pressure is good. Add a good fuel treatment to the fuel tank to clean injectors

Dave H
Apr 13, 2010.
Sorry have changed the fuel filter also and added shell diesel and wyn's injector cleaner into the fuel to help clean them up. Now it's difficult to start.

Tiny
Michael_cat_uk
Apr 13, 2010.
This could be a low fuel pressure fault .. fuel pressure at WOT (wide open throttle) sounds like it is working correctly as you have no loss of power ..so it could be the pressure regulator going bad or the pump going bad and losing pressure over periods of innactivity (overnight).. have the fuel pressure checked @ KOEO (key on, Engine off) .. I do not have the spec's for this vehicle as it was not released in the USA .. your local library or autoparts store should have a repair manual for the vehicle .. or most garages will have the spec's ! .. also have a garage/tech check the MAF/MAP (mass airflow/manifold absolute pressure) sensors are in the correct ranges @ cold start !


http://www.2carpros.com/forum/automotive_pictures/266999_AAA2_1122.png


Dave H
Apr 14, 2010.
Many thanks - I'll give it a go. I know that the mass air flow was updated a recent while ago.

Also when I bought the car it started fine, but when it stopped starting, I realised that the connection to the fuel pressure regulator was unplugged. I plugged it in but it made no difference. Maybe this was not working and they unplugged it to stop the fault being recognised.

Strange how it started fine for a while though.

Michael

Tiny
Michael_cat_uk
Apr 14, 2010.
Sorry I got it wrong - Ignore the regulator.

When I bought the car it was the Fuel Filter Wiring Connector which was unplugged!

Any ideas why it was fine, but now won't start? What does the connector do? I looked in the Haynes book and it says it's a 'fuel heater wiring connector'.

Michael

Tiny
Michael_cat_uk
Apr 15, 2010.
There is a small fuel heater in the base of the filter housing. This aids vehicle starting on cold days. This is probably faulty and this is why it is unplugged. Replace this heater and reconnect the wiring
AD

Dave H
Apr 15, 2010.
Any ideas where I can buy this from?

Michael

Tiny
Michael_cat_uk
Apr 17, 2010.
Most good autoaparts stores will be able to supply this .. halfords or any of the small independant stores will be able to get it for you if they do not have it in stock ..I'm not hundered percent sure if on this model it is actually built into the filter housing !

Hope this helps


http://www.2carpros.com/forum/automotive_pictures/266999_AAA2_1135.png


Dave H
Apr 17, 2010.

AD