FRST High idle, no boost and rev limit at 3k rpm. What is wrong?
#1
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FRST High idle, no boost and rev limit at 3k rpm. What is wrong?
Car: Fiesta RST ZVH EFI
Hi, I'm still scratching my head about the possible causes of these symptoms.
The car idles at 1.5k and this rises to 2.5k if I push on the brake pedal. When driving the brakes are awful, I have no boost and when under load it will not rev past 3k rpm. If in neutral the car will rev to the red line. Also when I pump the brakes with the engine off then apply pressure whilst starting the car the pedal doesn't move, does this mean the servo is faulty? Could these problems be
linked?
I was considering it may be:
Faulty servo.
Faulty TPS not letting it idle or rev properly.
Vacuum hose although they all look fine.
Limp home mode?
Any suggestions would be greatly appreciated as I'm running out of ideas. Thanks.
Hi, I'm still scratching my head about the possible causes of these symptoms.
The car idles at 1.5k and this rises to 2.5k if I push on the brake pedal. When driving the brakes are awful, I have no boost and when under load it will not rev past 3k rpm. If in neutral the car will rev to the red line. Also when I pump the brakes with the engine off then apply pressure whilst starting the car the pedal doesn't move, does this mean the servo is faulty? Could these problems be
linked?
I was considering it may be:
Faulty servo.
Faulty TPS not letting it idle or rev properly.
Vacuum hose although they all look fine.
Limp home mode?
Any suggestions would be greatly appreciated as I'm running out of ideas. Thanks.
#2
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check the servo pipe, start the car up and listen for any sucking / hissing noises.
put your foot on and off the brakes you can get a m8 to do this while you listen under the bonet to see if you get any funny noises. it deffo sounds like a servo problem.
you could always try removing the servo pipe and blocking it up to see if that helps althought i wouldnt advise driving with the servo pipe removed unless you got strong legs!!.
check all the boost hoses / clamps, give them a squeeze see if any of them are very soft, or have splits / cracks. failing that take it to a garage.
put your foot on and off the brakes you can get a m8 to do this while you listen under the bonet to see if you get any funny noises. it deffo sounds like a servo problem.
you could always try removing the servo pipe and blocking it up to see if that helps althought i wouldnt advise driving with the servo pipe removed unless you got strong legs!!.
check all the boost hoses / clamps, give them a squeeze see if any of them are very soft, or have splits / cracks. failing that take it to a garage.
Last edited by RSargie; 19-11-2009 at 09:18 PM.
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