Stuttering under acceleration and rough idle SOLVED

For a while I've been having issues with serious stuttering under acceleration (not to be confused with a misfire, or a cold start kangaroo, nor a flat spot or a brain haemmorage) along with a really rough idle, so I've been chasing down the most obvious candidates for vacuum leaks after already changing plugs, coils, air filter, and cleaning throttle body and injectors etc etc.... The F4R engine seems to be very prone to varying and inconsistent fuelling issues and I wonder just how many of these are basic vacuum leaks in poorly paired components.

My three main candidates for unregulated air entry are the MAP sensor, the PCV Valve and the Rubber Inlet Hose where it joins the airbox. All these items have 'dodgy', or should I say 'Renault style', fitment issues. My Map sensor and PCV valve felt very loose in their housings and the Rubber Inlet hose doesn't fit particularly well onto its oddly shaped housing coming out of the airbox. The housing is not circular, but rather the plastic folds in on itself creating a spur on the inside and leaves a gap under the hose rubber through which air can get into the inlet manifold and mess things up.

My solution....
• I used two new 6.5mm x 2.5mm (not 7mm x 2mm) o-rings on the MAP sensor and zip tied it down.
• I used two new 12mm x 3mm o-rings on the PCV Valve, which now fits very tightly into its housing and doesn't wobble around like before.
• When refitting the rubber hose at the airbox end, I rotated the jubilee clip so that the base of its screw fitment presses into the y shaped lip on the airbox housing better and then tightened up the screw to within an inch of its life. The hose has a rubber block to set the position of the back of the jubilee clip screw fitment. However, as you look at it in this set position rotate the the clip towards you so that the screw head is vertically higher by about 10mm and then tighten up the jubilee. Doing it this way I get a better seal using the screw block of the jubilee clip to press the hose rubber into the oddly shaped gap in the airbox housing ...(fecking Renault)
 
Thanks for this PaulV. Randomly came across your post and found I had the same issues without even acknowledging them. I'll get to fixing properly but my MAP sensor was extremely loose. I grabbed a bit of wire and tied it down as a test. Holy F**k!!! The car is performing SO much better. A lot more power.
 
Iv just made mine slightly better by replacing the thermostat, struggle get to 2 bars on the temp gauge and was very hesitant and kangerooing, put a low temp stat in from Euro, now goes to half way and drives A LOT better!
 
Iv just made mine slightly better by replacing the thermostat, struggle get to 2 bars on the temp gauge and was very hesitant and kangerooing, put a low temp stat in from Euro, now goes to half way and drives A LOT better!

How easy was it to change the thermostat? Mine hardly goes above the 2nd line even on spirited drives. Could you link the thermostat you bought?
 
Make sure the engine is cold so you dont get bunt, remove the induction pipe between the engine and the battery and you will see a coolant pipe going onto a metal housing with 3 8mm bolt heads in a triangle form, remove them, the coolant will drain, stat will pull out, refit your new 1 and build back up, fill your coolant and unscrew the bleed screw where the coolant pipes go into the bulkhead being carefull not to drop it as they are fiddly, wait for the air to go and you get a nice flow of coolant, refit screw, refill coolant, drive and re-check coolant.

https://www.eurocarparts.com/ecp/c/...c1b4dc9c5a0cb2aa4598fe59b299b2ef87848d&000325
 
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Getting the right thermostat is important 75Degree rating some have used 80Degree ones the engine runs hotter but nearer the cooling fan turn on point so expect the cooling fan to come on more if the higher temperature one is used. Another point is that on the some thermostats there is a little bypass hole which should be at the highest point when fitted I saw somewhere that the Clio cup guys drill a hole of a certain size maybe to allow a reasonable bypass or release trapped air in the system. This guy has a lot of videos on 197 maintenance jobs.

https://clio197.net/threads/thermostat-change-advice.56208/

The video direct youtube
 
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Getting the right thermostat is important 75Degree rating some have used 80Degree ones the engine runs hotter but nearer the cooling fan turn on point so expect the cooling fan to come on more if the higher temperature one is used. Another point is that on the some thermostats there is a little bypass hole which should be at the highest point when fitted I saw somewhere that the Clio cup guys drill a hole of a certain size maybe to allow a reasonable bypass or release trapped air in the system. This guy has a lot of videos on 197 maintenance jobs.

https://clio197.net/threads/thermostat-change-advice.56208/

The video direct youtube

This, I would buy genuine, the first one went and I was due a long driving trip, so I bought Gates one (a very good company that make our Cambelts etc) and it failed not long after, I then bought a genuine and it has been great since for a few years.