intermitant fault, stalling engine.

casseus

hey all, i got rid of my chrysler neon gen 2.

i baught a renault megane II 2004 on 1.4 16v, and before you ren haters start bashing ill do it myself to save you the bother, oh no another french peice of tat, the problem is i bought a renault, poor me, ROFL you baught crap etc etc.

the problem is intermitant, starts fine cold, no rattles, then engine warms up stop wait 5-10 mins, then start again starts-struggles-stalls, will do it for about 3 attempts, then will idle at 800 rpms, hold down throttle at 3000rpm for about 30 seconds then release will idle at 900 rpms. theres no rattles from the timing side of the engine (dephaser cam ruled out) have replaced what i though maybe a faulty crank sensor (tdc sensor) wich did help it a bit i must admit as the engine seemed more responsive, then i replaced the coolant temp sensor ( as ren forums has mentioned these having stalling issues when they go faulty) and the engine seems to run a bit better as before i replaced it the engine surged like it had a ignition problem, but hasnt cured the stalling issue.

i'd like to pick some of your brains and throw some problem solving at you guys to see what you think could possibly be the issue.

ive spoken with atrixblue, he's plumbed in his fault code reader, wich threw up 2 main codes of interest.

P1328. unspecified code refure to manufacturer for details. atrix said he would need a renault CLIP fault code reader in order to read the code properly.

and UPSTREAM oxy sensor. atrixblue run a live oxy sensor test to see if the code had any bearing, both sensors read fine when accelerating de accelerating and cold start up and code erased itself, he then checked the wiring to the sensor with a volt meter all fine, his explanatory theory is, when the car is stalling and im restarting it, unspent fuel is being ignited causing a high reading to the upstream sensor, because ive been holding my foot on the brake and accelerator to prevent stalling, nothing to worry about but if i continue to do it over a long period i could damage the cat converter.

my mind is now sitting at a few things that maybe the cause,

1. pencil packs worn, i have two that have maroon heads one with grey head and another with black with bremi wrote on it thats the newest one wich is 3 weeks old, atrix said it best to change all four in one go but that was done under warrenty i had no say over what was done to the coil pack, theres a new revised set of coil packs out that are OEM for the new megans made by VALEO (green heads) that atrix recomended i have fitted when another one go down.

2. camshaft sensor faulty.

3. stepper motor on the throttle body mine is the second phase throttle where the stepper motor is side mounted at the timing end (left hand side) of the throttle housing the first phase throttle are common to failure where the stepper motor is located at the back of the throttle body, wich is why im in a bit of doubt as that being the problem, but not ruled out.

4. alternator, mine has a clutch type pully on its spindle.

5, aux belt tensioner, on looking at mine it seems to move when the engine is idleing and a rubbing type noise can be heared, but the belt is tight, not loose when you stop the engine and hand crank the engine a full cycle and no squeels.

6. i know it has been ruled out, but cant help to not keep it in mind, dephaser cam pully, these are a problem in their own right, symptoms are loss or lack of power ( my engine is pretty responsive) a loud rattle for three to four seconds on strart up ( i have no rettles) OR constant rattle no power (i have power). dephaser cam is for the VVT side of the timing and some megans dont have that cam fitted to them seems to be centred around the K4 engines an expensive repair, but seeing as my timing belt will need replacing in the next 6000 miles it will be changed amoungst the belt tensioner idler and water pump anyway as a precaution renault do these only and can be bought as a kit or on their own, i airing to buying the kit with a water pump and new thermostat, fluids and service and have a good indy garage do it.

so what do you guiys think this problem could be????

harveybobbles

Coil pack's are prone to fail on them.

goosander

Other possibilities:

Excessive vacuum in fuel tank due to blocked vent pipe or faulty filler cap - car runs for a bit sucking fuel from the tank which creates a partial vacuum, eventually fuel pump struggles to overcome vacuum reaulting in fuel starvation. Try removing filler cap when car is running badly.

Heat soak - heat from the engine when parked causes fuel to vapourise in the pipes resulting in bad running. Cures itself once cooler fuel has been pumped through. Is the car missing any heat shielding?

casseus

the car has all its sheilding, removing the fuel filler cap is new one one me, these cars have a quick fill cap i.e no filler cap just a metal sheild that flips up when a filler nozel is passed into the pipe then furthher down anti syphon bung. to remove that you have to remove the plastic housing it sits in an then the pipe will be free floating an unsecure and will rattle like no mans buisiness.

i am airing on the coilpacks and the valeo upgrade is prefured ill get a set then post back results.

casseus

UPDATE:

i decided to take off the throttle body for inspection, was a bit of a PITA i must say, theres no room to remove the throttle airbox situated at the rear of throttle housing unless you drop the engine off its mount on the timing side, i couldnt be bothered with all that so i decided to push it back as far as it will go and struggle with the two bolts holding the throttle on, removed the vacuum pipe ontop of the throttle and removed from car on inspection there was lot of dirty gunk in the bore and flap, i removed the stepper motor casing to inspect the inards, on looesening the 4 hex bolts water poured out, then when it came off, there was water inside surrounding the motor, i got water dispersant spray sprayed it up then cloth'd it off, the rubber sealed looked pinched, so i got some silicone sealant and put a fine bead over the rubber seal, refitted cap and tightened back up, i then doused the bore of the throttle in petrol and with cloth removed all the gunk from the bore and flap untill i could see no more gunk stuck anywhere, replenished the oily protective layer on the bore and flap with a bit of lubricant oil that i have for my air rifle, inspectec the o ring seales on each end wich seam fine and cleaned them up a bit to get oil off them, reached around to inlet manifold cleaned the hole the throttle sits in untill grease free, sat the throttle back in and tightened the bolts, back up and refitted airbox back on, on plugging in the vac pipe that sits in the head of the throttle noticed it had no O ring (i woundered why it came out so easy) fitted a o ring to it, sat it back in the hole untill it was where it was before but it was loose so i pushed hard it poped in further and hey presto it made a seal.

i mentioned a dump valve type of sound wich i thought maybe the clutching system on the alternator, well its gone now, it was infact air leaking from the vac pipe in the head of the throttle, the car hasnt stalled at all since i cleaned out the throttle housing and resealed the vac pipe and o ring replaced on servo vac pipe, engine idles perfectly, 900 rpm when warn 1000 rmp when cold, engine is alot better on MPG was getting 32 mpg doing school run and small trips, now getting 38 mpg, and 44-52 mpg on a good run. happy days. hope this helps for anyone out there with similar probs, remeber if you have a problem like mine and hear the whooshing sound on changing gear and not to be confused with a rattling sound it could be as simple as a clean up and o ring replacement.

cyclonebri1

Well too late to help but we had exactly the same issues with my daughters car.
Drenching the stepper motor and throttle housing with carb cleaner cured it in minutes.
They do seem very prone to that particular problem (plus quite a few others) ;)