On-going tickover/stalling issue

[lakemaligne]

Hello mjb and others , Just to let you know where I am up to on my car.
I have just replaced the VSS and heat shield, and the car started fine, ran well, with no faltering or hesitating or stalling until i went round a roundabout ,depressed the clutch to change gear and the engine died. It started back up ok, but then started to rev up and down for 5 seconds , trying to die, but then settled down and idled ok. The car then hesitated and tried to die a few times on the way back home. The car has also tried to die /falter on the straight ,and on a full tank of petrol,so i think i can rule out fuel pump starvation.So I reckon the VSS was not causing the fault ,do you agree?.

Do you think I can rule out the crank shaft sensor as a cause also.?.

I have been thinking about the theory that my problem may be caused by lack of fuel pressure, or intermittently bad fuel air/petrol ratio,especially as i keep getting the "Irregular fuel distribution" fault recorded by the ECU,and the fact that my engine hunts up and down after it has had its gliche. The Master Tech at my dealer said that he tested the pressure in the fuel rail under load and got 3.5 bar and when he removed the vacuum pipe from the FPRV,the pressure altered by 0.5 bar,and advised me not to bother renewing the FPRV.

i am coming back round to thinking that my fault might be caused by a faulty SM/IACV, I am beginning to think that the way this fault keeps coming in and out ,one trip all is fine, then on the way home it plays up, must be down to something physically sticking ,like a moving part in a stepper Motor for example. Am I right in thinking that the SM only comes into action during idle conditions ,and after that the ECU takes over ? If the plunger on the SM moved while the car was cruising,could it cause the air/fuel mixture ratio to alter and cause the car to falter and try to die.? Is this plunger on the SM moved in and out via a worm and wheel type gearing, powered by a tiny motor or does it use a solenoid. Does the plunger move out wards into the air stream to restrict the air flow , and then in again to increase air flow to control the idling circuit ? Is it ok to squirt electrical switch cleaner inside the unit and then squirt WD40 inside to lubricate it,or should i take it apart and clean it.
One other thing i have noticed was ,with the engine ticking over, engine warm, when I slowly turned the throttle spindle by hand , the revs do not go up at all until I had rotated it through about 5 degrees. Once the engine speed started to rise I then stopped turning it and held it still ,and I noticed that the revs kept climbing up to about 1500rpm,then settled down. Is this normal or is it indicating that the TP is playing up ?, and could this be causing the jerking as I come on and off the throttle ?

[lakemaligne]

This is just to let all you guys know ,especially MJB ,who I know tried his best to help me diagnose my very irritating idling/stalling fault on my 406 , but then gave up i reckon ,but I have finally come to the end of my tether with my car ,because yesterday on the way home after a fair run, it bogged and faltered for a whole 10 miles ,light on the whole time, and at every junction the idle was a rough as old boots, and it kept trying to die. Then a bit further on at a "large busy traffic light junction", the already rough idle got much worse, the "STOP" light came on the dash and the engine note changed to a loud clattering, jingling awful sound ,a bit like the car was having a colossal "pinking" session, then it died. I tried restarting it , but the engine just spun over and didn’t even try to fire up. Great I thought ,the dealer is finally going to get the car knackered for once .The recovery guy delivered my car to my local Peugeot dealer ,and the Master tech who has been trying to sort my car out for me, said it started first timethe next morning ,and ran like a dream. He left it ticking over for 20 minutes to get it good and hot, and blasted it down the A45 ,and stopped at several junctions to bring on the fault and NOTHING! .So guys what do you make of that, any other ideas apart from dropping a lighted match into the tank

[Welly]

What do I think? I think life is too short to be bothered about a car worth sub- £400 keeping me awake at night. I personally think you need a new fuel pump and each injector cleaned on a proper test rig. Other than this you could spend countless money, trial and error and guesswork trying to find whatever's wrong and you'll either succeed or you won't Perhaps it is time to throw the towel in? maybe even buy another 2.0 and swap all the bits and bobs about until it works properly? you can't drive about in something that keeps cutting out - you could get in a right mess at a busy junction somewhere

[lakemaligne]

I actually replaced the fuel pump quite recently and the filter ,and double relay. Doing some searches on line ,these latest symptoms seem to indicate that the crank shaft sensor is failing when hot ,so i replaced that as well with no luck.

You are right ,I do need to move on now and accept that i have wasted enough money and time on what is obviously not going to reveal itself.So i have decided to downsize and see how a second hand Polo,Yaris and new shape Corsa all compare. I will take my 406 along ,explain what keeps happening and see if i can trade it in on what ever i decide to get. I will let you know if i get offered anything thing for it. I figure she is worth around £300-400.

[exvaux]

Having just joined the forum after aquiring an 406 and reading through the posts, I noticed your problems. I'm sure you have already checked and at this early stage in ownership I am not certain if the 2.0 petrol has one, but, have you checked the MAP sensor? Had similar problems with a vauxhall corsa which came down to a faulty one. Also needed the plastic vacuum pipe replacing as it had perished. Hope this is of some use.

[lakemaligne]

Hi exvaux, yes my 406 has a MAP sensor ,which was replaced but made no difference,but thanks for trying.

[lakemaligne]

Hello to all who have tried to help me. Just to let you know which car I went for and what happened with my old 406.I had a test drive in a 2007 Vauxhall Corsa 1.4 petrol “Design”, which I think is the top of the range and was instantly very impressed with how smooth ,quiet, and perky it was. The build quality was on par with the Polo and was more spacious inside than both the Yaris and Polo and it handled and drove like a much bigger car, not on the same level as my old 406 though. The Corsa was for sale at £7000 , and had been bought from the same dealer three years previous by an old guy who only toodled around Rugby in it and it was still in show room condition inside and out. I had not intended on getting a glitzy top of the range car, but this seemed too good to be true, with alloy wheels, Aircon,part leather seats ,flash interior, rain and head light sensors, electrically heated/adjustable mirrors, posh dash and controls and it was silver, my favourite colour, and it had only done 13,400 miles. So I asked the dealer to consider part exchanging my 406 for the Corsa, told them about the intermittent fault and without looking at my 406 ,having asked a few questions, he frowned at the age, bulked at the 167,000 miles and said not more than £300. However , when he saw it gleaming away in the car park, he walked round it very slowly ,then called his colleague over to inspect it. They were both very impressed with it’s condition inside and out and once they discovered I had been the only owner from new, had a fully stamped service log book and all the MOT slips plus job invoices , they said , let’s see if it runs as good as it looks. They took it for a test drive, and offered me £600 for it, which I accepted. So I now own a Corsa, which is very nice to drive, but I still miss the 406 for it’s looks, power and smoothness. Thanks again for all your help guys.

[Welly]

That's great, I think you've done the right thing really, I hope you enjoy the new car - the new Corsa is quite 'cool' out there.

If you've had the 406 for 14 years you've not done bad really, especially to get £600.00 as a trade in.