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)
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)
