C3 Refuses To Start

[Guest Edd1]

Hi all.

Right, now for a list of symptoms that hopefully somebody will be able to point me in the right direction with: A couple of months ago my C3 (1.4 petrol) decided to intermittently start, or not as the case may be. I took it to a dealership where I bought it 4.5 years ago and, after checking on their computer with no fault registering then hitting bits etc , they decided it was the fuel pump so replaced it. It wasn't that so I got my money back and they left the new pump in! It got to a stage when I knew it wasn't going to start as, if it would give a humming/buzzing noise when turning the key without starting the engine. I now know that If I don't hear this noise it won't start. After a bad spell a few weeks ago I took off the ecu connectors and sprayed them with electrical solvent ( not wd40!) and this got it going (engine running brilliantly by the way) and I thought problem was cured but symptoms developed again. Everybody is stumped now and conclusion is that it might have something to do with immobiliser/ecu. I have checked as far as possible the wiring but have noticed in the connector blocks at ecu a sort of gummy stuff coming away when sticking in wire for continuity - I have cleaned this as much as poss. but to no avail.

1. Does anyone know waht the humming noise is when half turning the key - if I know that it might point me in some direction.

2. has anybody else had this and if so, point me more specifically in the right direction please!!

Cheers

Eddie

[stimulator]

Isn't the humming noise the fuel pump running.

 

Did you use electro cleaner or electro lube.

There is a difference one total evaporates the other leaves a film on the parts. WD40 is a NoNo for this sort of job as it's a moisture dispersant which eventually goes gummy and attracts dust etc.

 

The gummy stuff that is coming out of the plug could be a broken down capacitor or it's bad corrosion on the pin.

 

Both of my C3s are diesel and my Pic was diesel too so the petrolm engine are a different area for me.

 

On my Pic when the imobiliser didn't work the engine would turn but not start and the cure was pull out the key and wait 10 secs and it was then OK.

Have a look on the Pic site in technical at ECU you might get some pointers from there.

[Guest Edd1]

Isn't the humming noise the fuel pump running.

 

Did you use electro cleaner or electro lube.

There is a difference one total evaporates the other leaves a film on the parts. WD40 is a NoNo for this sort of job as it's a moisture dispersant which eventually goes gummy and attracts dust etc.

 

The gummy stuff that is coming out of the plug could be a broken down capacitor or it's bad corrosion on the pin.

 

Both of my C3s are diesel and my Pic was diesel too so the petrolm engine are a different area for me.

 

On my Pic when the imobiliser didn't work the engine would turn but not start and the cure was pull out the key and wait 10 secs and it was then OK.

Have a look on the Pic site in technical at ECU you might get some pointers from there.

[Guest Edd1]

Hi.

Thanks for the reply. I have been told by a couple of people that I should hear the fuel pump priming up and you have confirmed that is what the noise is. I am getting the engine turning over but not starting. I have taken the key out, disconnected the battery and left for a few minutes (advice given by a citroen service manager when I took it in), reconnected the battery, left for a further few minutes and tried again - to no avail!

The electro cleaner was the rapid evaporating stuff and I have now been through 3 cans of it. The only joy I had was with the first can.

Now that we have established the fuel pump isn't priming, where does that lead us - wiring re. the fuel pump or are we still looking ate immobiliser / ECU. I have heard it is possible to send the ecu to be reprogrammed to bypass the immobiliser and am willing to do this if I am confident it will work. I need to eliminate all other possibilities though as I am mean as well as skint.

Cheers again

Eddie

[Guest Edd1]

New development.

Have been out at the car and, while sitting inside turning key in the ignition I heard click sounds from the BSI. A while (30 seconds ?) after taking out key it clicks again as if something is making contact inside. Turn the key again and a click once more - is this normal or a significant indication of a breakthrough?

Eddie

[stimulator]

The imobilser uses the passive chip in the key fob. I know this is a silly question BUT do both of your keys produce the same effect.

 

There is an aerial wire in the column and the chip forms the missing part of the circuit.

 

try this.

 

Open the key and locate the chip, it's black and mounted by the key blade.

 

remove it from the fob and tape it to the column cover with sellotape or similar.

 

Now insert the key does the engine start.

 

If it does then the immobilser is OK.

 

There were problems with Picassos burning outy their ignition key blocks due to dirty pollen filters. NO don't stop reading it's true. when the pollen filter is dirty the interior car fan has to work harder to move the air so the current load increases. The fan is fed thru the ignition switch and the contacts heat up and melt. result the fan doesn't work but also the switch makes bad contact.

[paul.h]

Intermittent starting/running is often a symptom of failure of the crankshaft position sensor on many cars. This does not always give a fault code so may be hard to detect with a fault code reader. Easiest option is often to just replace it.

[Guest Edd1]

Thanks for these replies. I will try the chip taped next to ignition switch and see if thatworks. Interesting about the pollen filter - I did the servicing last time and didn't do the pollen filter - as I only do about 5000 miles a year the filter hasn't been changed in a long time. Also, the wires blowing kind of goes some way towards explaining another symptom I forgot to mention. With everything off the car went into eco mode when left and the battery was connected - it must have been leaking current somewhere and this could be the start of a positive investigation to explain that.

Many thanks again.

Eddie

ps please keep the suggestions coming.

ps the crankshaft position sensor idea was one the AA chap thought of so I replaced it with a new one (assuming it's the same as what he called speed sensor - 1 bolt holding it on near flywheel?). I thought that actually cured it at first as the car startetd when I replaced it but soon developed symptoms again.

[Guest Edd1]

Update: I've been in touch with places that check and repair ecu's. Guess what - this ecu is one that nobody seems able to check/repair! Citroen use ecu's (at least in my C3 anyway) that seem impossible for the ecu experts to diagnose and repair faults. Has anybody else experienced this kind of thing?

[CE08LDB]

My Brothers 2006 C3 Exclusive is refusing to start on one of the keys. My brother was involved in an accident in it a few weeks ago and at the scene of the accident I tried to start it and it would try and turn over but that was it and A Warning Message Came Up Saying Anti Theft System Fault. I put it down to the accident as the Front of the car took a hard bump.

 

So my brother had the car back yesterday fully repaired. The Garage had the spare key to drive it. So I tried the key that wouldn't start it when the accident happend and same thing happend Anti Theft System Fault. The Remote will open and unlock the car. The key will even turn on the accessories in the ignition and it will try and turn over but thats it. Now other key I fixed as that one broke works alright.

 

Stupid things. I prefere the Pin Number System that the Saxo and the Xantia's and Zx's used to have

[Guest Edd1]

New developments!

I decided to send the ecu to the ecu clinic, 1st class recorded signed for post. That was 2 weeks ago and it hasn't been delivered yet!!! Looks like ecu is possibly lost in post so am well and truly up the creek without paddle and without enough money to buy new ecu etc etc etc.

am a bit hacked off with my luck right now.

Eddie

[CE08LDB]

Sorry To Hear that Mate.