High Manifold Pressure at Idle

Discussion in 'Engine, Gearbox, Exhaust and Air Intake' started by Meeteepao, Dec 16, 2019.

  1. Meeteepao

    Meeteepao

    Messages:
    9
    Car:
    Renault Clio R27
    Hi guys,

    I hope you and your lovely Clios are doing well.

    While getting a performance map fine tuned for my Clio R27, I was told by the tuners (Ktec Racing) that my data logs show that the car is running with a high manifold pressure at idle. They asked me to check the cam timing.

    I spoke to the Renault workshop in Dubai, they said its impossible for this to be due bad cam timing but are willing to check (diagnosis will take time and cost $$).

    Google says it could be due to:
    • Leaking intake manifolds downstream of the throttle valve (e.g. due to defective intake manifold gaskets, hoses, etc.)
    • Defective engine exhaust valves/hoses
    • Leaking brake boosters
    • Leakages in the vacuum system (e.g. vacuum-operated actuators, brake boosters, lines, etc.)
    • Defective EGR valves (permanently open)
    • Defective idling actuators
    • Idling status of the engine is not recognised by the control unit (defective throttle potentiometer, throttle switch)
    • Defective or dirty throttle valves
    • Incorrect or faulty air filter inserts
    • Carbon deposits or other blockages in the intake manifold

    I recently installed a (slightly used) Ktec Air Intake kit on the car - I believe the issue is possibly due to a leak in the intake hose.

    Has anybody dealt with this issue before?

    Thank you.
     

  2. bedoef

    bedoef Platinum Member

    Messages:
    138
    Location:
    Dubai
    Car:
    2012 Clio RS 200
    I see you Hamza....

    Have you had your intake manifold or throttle body cleaned ever? Maybe start there. Craig at AUH cleaned a lot of crap out of mine last year and that helped smooth out my idle.
     
  3. Meeteepao

    Meeteepao

    Messages:
    9
    Car:
    Renault Clio R27
    Oi Clark!

    Thanks for the suggestion. The issue with mine is that my idle is absolutely perfect. In fact I didnt know about the issue until Ktec sent me an email after reviewing my data logs for the ECU tune.

    My car does very occasionally jump when I drive from a stand still in 1st gear - I'm not sure if this has got something to do with the camshaft timing or whether its the "kangarooing" issue a lot of people talk about - linked to the loosely OEM installed MAP sensor.

    Its got me worried a bit - because my tuning has been put on hold until I have this issue diagnosed. I've also got a shipment of parts coming hopefully in early Jan (Cams, Uprated Valve Springs, Belts and pulleys etc).

    Keen to have this issue diagnosed as soon as possible.

    Renault guys suggested to bring the car in so that they hook it up to their PC and monitor the cars behavior.

    I am also doing an intake manifold and throttle body port and polish with the cams upgrade, so that should that should help in the grand scheme of things, once the other upgrades are done :smile:
     
  4. bedoef

    bedoef Platinum Member

    Messages:
    138
    Location:
    Dubai
    Car:
    2012 Clio RS 200
    Mine idled fine as well, but turns out it was restricting breathing a bit and the car felt more powerful after the tune-up, so to speak. If you are getting the intake machined, then probably don't bother with cleaning for now as that can be done once.

    If you won't charge much for a diagnostic test, just take it to the dealer and see what they say.
     

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