I need help from people that know !!!
My garage can't sort this one.
Rover 416, petrol, Rover engine, manual g/box 50,000 miles 40mpg.
At small throttle openings, the engine & car jerks forwards / back like a kangaroo start.
For example, the engine could be on the over-run and you press the throttle slowly & gently to take up the drive & accelerate you would get maybe 3 seconds of 'kangaroo'.
Sometimes I have to dip the clutch to break the cycle.
Most noticable in lower gears, obviously.
The upper engine mounts are sound and the rear anti-rock engine mount is brand new. New plugs & spark leads from plugs to distributor and diagnostics find nothing.
Have cleaned throttle butterfly, its pivots are unworn & action smooth. No detectable manifold leaks.
Any help you can give to prevent whiplash injury would be great !!!
Thanks, Vinnie.
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Check out the condition/settings of the thottle potentiometer and the idle air control valve.
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There is also a mount underneath o/s chassis member below the top mount. has a bar connecting to engine block. it may not be the cause but worth a look. Diagnostics wont show any faults unless they occur at time of Diagnostics.
And as this ECU has no memory cannot record a fault. But what I mentioned may well cause it.?
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Was mech1
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Check the condition of the rubber hose between the airflow meter and the plenium chamber. Check the ends for distortion under the jubilee clips and if it's a concertina one, the rubber sometimes cracks on the underside. Also (as Aprilla suggests) check the throttle position sensor.
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Check the condition of the rubber hose between the airflow meter and the plenium chamber. Check the ends for distortion under the jubilee clips and if it's a concertina one, the rubber sometimes cracks on the underside.
Good suggestion - I had this (cracking at concertina point) on a Vauxhall.
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Unfortunately the Rover uses a map sensor so this wouldnt apply here. Go with the throttle position sensor problem or possibly a blocked hose to the map sensor inside the ecu. Neither problem will show up as a fault but can be observed using serial data via the diagnostic port with the correct equipment.
Andrew
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Simplicate and add lightness!!
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Just what I was going to say Andrew!
Check the inlet manifold to MAP sensor pipe is clear of any oil. This will give this very symptom.
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groups.msn.com/honestjohn - Pictures say a thousand words.....
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Andrew,
Thank you for troubling to help me. Sorry I wasn't able to get back to you earlier, been on holiday.
The MAP sensor is built into the ECU. The small pipe from the plenum to the MAP has a fuel trap inline. Can blow through it OK with no air leaks either. If the fault is in this area it can only be in the MAP itself.
You mention also the throttle position sensor. I have givenit a visual check and it looks OK. Is there any electrical multimeter checks that you know of that I can give it? Any resistance values?
The car goes for its MOT tomorrow and have asked the garage if they can find the fault. He thinks the mixture may be too weak, it does 41mpg driving steady so he may have a point.
Anyway, thanks again Andrew. It's nice to know there are people around that give up their free time to help others.
Best wishes, Mark.
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The mixture is controlled by the ecu.
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\"Nothing less than 8 cylinders will do\"
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>>He thinks the mixture may be too weak, it does 41mpg driving steady so he may have a point.
That MPG is about right for the 1.4/1.6.. I would also try. as has been mentioned. Dizzy cap and rotor arm as they did carbon up
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Steve
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New distributor cap?
I had this problem with a Rover once, and that sorted it out.
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