clio 1.5 dci 80 cold start problems

hi all,

I have a 2002 clio dci 80 bhp (updated to 100bhp by a tunit black box)

When the temperature drops to anything less than 20 degrees (I live in madrid so trust me, this only happens when we get to around november)
the car does not start.
I wait for the glowplug light to go out (around 3-4 secs) then i try to start. Usually it stalls straight away, then I have to try again around 4 more time, or if it does start the rev counter needle hovers around 200-400 revs and stalls shortly afterwards.

I have already had the car in a renualt dealer who claims they could find nothing wrong with it. Now the car is out of warrenty and im sure it will cost a lot to get it seen to.

Ive owned a few diesels (peugeot, rover) and never had a problem cold starting the car. When the ambient tempetature is around 20+ there are no problems.

I have not checked yet to see if the problem is the tunit modification but im not convinced it is

Any clues - I was thinking glowplugs.

James,

Hiya!

First off, for reliable combustion you need fuel, warm cylinders and air.

It sounds as though the car starts, but runs rough.

First off take the powerbox off to ensure the engine mixture is as its best and not hyped up by the powerbox.

If no change, get a digital volt meter and measure across the battery terminals when the ignition is first turned on. I believe the DCi has glow plugs. The inital warming of the glow plugs gives the battery a real hammering and you should see the voltage across the battery drop as it tries to warm the plugs. If it doesnt change, there may be a relay or solenoid in the engine compartment that will be in the wiring to the glow plugs - it may be faulty and not letting the juice from the battery get to the glow plugs. Also measure the voltage at the plugs to ensure each is getting the volts from the battery.

you can rule the battery out as being the problem provided the starter motor turns the engine over quickly and when measuring the volts across the battery as described above, the voltage should not drop too much, if it collapses to a few volts the battery is knackered.

Is the air filter blocked up? when the car runs does it run ok and with reasonable fuel economy, if so, rule out the air filter as a problem.

I have no idea whether the ECU holds any valves, relays or the like shut when the engine is cold. I think the fuel pump is manual so that shouldnt be held off by anything, there may be a fuel preheater on the DCi - if this is faulty the engine would struggle until it had warmed a little. In the UK, renault dealers are excellent for a call to their service departments - a nicely worded question normally gets lots of advice on what to look for.

hope that helps.

Andy

thanks for the help andy.
i was thinking of taking off the power box in case "as you agree" it is messing with the mixture.


The car "does" start eventually but sometimes the engine stalls literally straight away and then I have to start it again around 5 times. When eventually it does start the engine hunts up and down between 500rpm and 200 rpm and then eventually clears its lungs and idles at just below 1000 rpm

this is a little variable and sometimes it starts and only hunts up and down, as opposed to literally stalling and having to be re-started.

I have not tried looking at the air filter as yet (the car had the same problems this time last year - I took it into the garage and they found nothing on their computer test equipment - suspect nice warm renault garages and cold start problems are not a happy mix!)

I am wondering how long the glow plug light should stay on for after turning on the ignition for the first time. Mine only stays on around 4 secs, which I would have though a little short considering the ambient tempt (for example) is around 5 deg.

Cant wait to drive to andorra, now that will be fun trying to start the car.

thanks again,

ill take another look.

James.

Hi Again,

Sounds to me as though its either the mixture not being sufficiently warmed by the glow plugs (get the car started and hold the engine revs at 1500-2000 rpm for a minute to see if it eliminates the problem when you return to idle speed), or there may be insufficient fuel getting to the engine for cold running.
The ECU will add more fuel to each cylinder by increasing how long the injectors remain open for, so if anything, i'd expect your power box to help here as this is precisely how the powerbox works (unless its faulty of course!), otherwise, the ECU may not realise the engine is cold, it will rely on a temperature sensor for this, which could be faulty, if this is so, i'd expect the rough running to last for a while rather than a minute or two, until the engine is warmed through.

Last thought is that the air entering the engine may be too cold, renault will be able to tell you if there is any kind of flap or valve that may be sticking, as the dci has an intercooler to cool the air befiore it enters the cylinders, could be this is stuck on and cooling the already cold air.

Wont be around till monday, good luck. Dont forget, the dci80 is a great car, worth the effort!

Andy

how'd you get on James?

Andy

hi Andy,

Well, sorry i didnt reply but I got sort of wrapped up in many other things no car related.

How did I get on....hmmmm...

Well the car is gradually getting worse. Generally it stalls around 5-6 times and when it does start it idles are 200rpm for around 1 minute until it rises to a stable 900rpm.

Pressing the accelerate at the point of the car reving at 200rpm does nothing - I suspect the ECU is taking over the control of the engine and will not accept input from the accelerator pedal - I guess it has some kind of potentiometer rather that a cable.

I did remove the engine chip upgrade and the problem seemed to persist.

I have contacted the Renualt garage (AGAIN !) as I am driving th Andorrra soon and I dont fancy the chances of the card starting well in - 0c.
there told me that, despite the problem not being solved first time (Well in my eyes not theirs) they would not do this free of charge.

So basically a problem which was not fixed in warrently could now cost me dearly now it is not in warrenty - GREAT !

So things as they stand have not changed. I am unable to check any of the things you mention as I dont have any tools at all

Any more thought ?

thanks for your help by the way, and for the record I saw your other post for the engine update - mine must be a dud because the performance difference is not that great :(

James.

Hiya!

Right, lets sort this out. If the engine runs fine once its warm then its a system related to when the engine is cold. These systems are:

The ECU - would expect it to result in the engine not running at all or the ECU light being lit on the dash board.

The air filter - if blocked the engine wont idle nicely, you'll have high fuel consumption too. Check the air filter is clean and not full of sand/leaves etc, this should ensure the engine is getting enough air. If not, need a new filter.

The fuel system - look at the pipe work feeding the injectors, if the pipes are translucent, you may be able to see in the pipes a few bubbles as the engines ticks over but if the pipes look empty of fuel then the engine isnt getting enough fuel - it may just need repriming or replacing the fuel filter or fuel pump. The ECU also controls fueling, leaving the injectors switched on for longer when cold so more fuel goes into the cylinders. As before, rough running can also (and very likely as they get a hammering) be simply a knackered injector preheater. Once warmed up preheaters are not as crucial to the smooth running of the engine so the problem disappears. unless you have the tools you wont be able to find the fault if this is the cause. If you can get your hands on a socket set and a multimeter then you could find out if and which one is dodgy.

This is about all I can offer. If you're keen to look after a car yourself, you need the Haynes manual for the car, a decent tool kit, a multimeter and lots of patience. Otherwise your at the mercy of the garages! And thats pretty much regardless of the car too.
Good luck,

Andy

Thanks for the help again ! Well see what the garage finds.
Its due a service so the filters will be changed - for further info (I though this unrelated though) I have had the ECU light lit before in the car.
I tried to start the car one day and the engine literally spun without even trying to start. At this point the engine stop light in the car was lit (It was summer so very warm incidentally). I tried several times to start but the same each time (light always lit) At this point a was beginning to crap myself as I though that the ECU was broken.
Being a computer hardware engineer i decided to unplug the ECU from the woiring loom and replug again. After doing this the light went out and the car started !. This has happended a few times afterwards and I always get around the problem by unplugging the ECU ! I have no idea if this is releated . Perhaps I have a dodgy ECU. ! I hope not - mega bucks
Thanks.

James.