ROUGH IDLEING, STALLING

[JOHNZ]

I own a 1993  rt 2.0 inj espace, a few weeks ago it started to idle erratically but just latley every time i come to a junction ie revs drop it stalls? starts up again straight away untill the next junction then again stalls and so on! changed spark plugs, ht leads, distributor cap, fuel filter  and a new battery etc basically a full service only a few months ago so dont think its that! engine warning light does not come on and it seems to stall once engine warms up but still revs erratic, checked breather hoses they seem fine, but noticed some oil in the throttle casing and air filter? do you  think it called be inlet manifold/throttle leak? asked a mechanic but he said not to get a diagnostic as engine light not on so wouldnt find fault. any clues anyone  do you think it could just be a sensor somewhere your help would be most apprecaited. johnz

[Anders Dinsen]

Hi and welcome to the forum!

I would point to the idle valve as the problem. These get sticky over time as dirt gets into them and due to the way it's made, it becomes difficult or impossible for the ECU to control it properly. Effect is unstable idle and stalls - but otherwise the car runs perfectly.

This drawing shows how it looks inside:


I disassembled one some years back and it looked like this inside:


The valve is located between two hoses - one going from the air filter exhit hose and the other going to the manifold - just between the radiator and the inlet manifold. Take it off the car and try spraying some wd40 into the valve. If you have thin fingers, you can use a finger to "exercise" the valve - it just rotates inside the body - until it's working better. That should get you running a while, but if it fails again, you will need a new valve.

Good luck!

- Anders

[renaultbiler]

Common problem on these engines (J 2.0/2.2) is also the inlet manifoil gasket.

[JOHNZ]

Cheers for the info, i will check & clean the idle valve as you mentioned let you know how i got on, is their anyway of checking the inlet manifold gasket etc without dismantiling thanks johnz, by the way its nice to find a site like this where others can dicuss and hopefully solve their motoring problems without having to fork out ridiculous prices that some garages charge just to look at your car, many thanks again johnz.

[paul-g]

Hi John, to check the inlet manifold gasket spray brake cleaner or something similar around the inlet manifold joints and fittings with the engine running but be very careful as this stuff is very flammable you should be ok as the exhaust manifold is on the other side, use it sparingly and if there is a leak the engine should rev up as the solvent will be sucked in.
As with the idle valve i had no success cleaning mine i had to renew it then the engine ran at 1800 rpm instead of idling, i then had to send the ecu away (after checking the circuit) to get it repaired. apparantly these ecu's suffer with age related idle control problems. it seems though you may be ok as yours is not racing so good luck with it and let us know how you get on....Paul

[JOHNZ]

Well i checked the idle valve, but it seemed to be working ok, but gave it a clean anyway, however i noticed the air flow sensor [located in air intake,before filter} was covered in gunk! so took it out and soaked it in white spirit for about 1 hour cleaned and put back in hey presto engine running a lot better, so far it hasnt stalled again idles better, but you can still  just about notice revs still going up  and down on idle and hesitates on acceleration maybe check leads etc ? thanks for the info saved me a lot of time by narrowing things down  john.

[renaultbiler]

That one is an inlet air temp sensor

[paul-g]

Good result there then, can you feel the car slightly surgeing on light throttle, flat road?  it may be down to a slow switching lambda sensor, also try cleaning the crank sensor hope this helps regards Paul.