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Jake, Automotive Technician
Category: Porsche
Satisfied Customers: 3935
Experience:  Experienced collision repair technician, Pulaski Tech graduate and DSM hobbyist.
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I have a porsche cayenne 2010, the vehicle is hard starting

Customer Question

i have a porsche cayenne 2010, the vehicle is hard starting
Submitted: 1 year ago.
Category: Porsche
Expert:  Jake replied 1 year ago.

Hey there, sorry for the delay.

So the vehicle starts and runs? While running there are no issues? just a long hard start?

Lastly, are there any fault codes?

please verify so we can continue,

Expert:  Jake replied 1 year ago.

Since your away at the moment, I will cover a few things while I await your return.

If the hard start occurred after a recent refueling, then it's likely the purge valve causing the issue. It's not very uncommon for the purge valve to get stuck (depending on the position) and cause hard starting from a rich/lean condition. This will also effect fuel mileage if you continue to drive like this.

Secondly the electronic throttle has been known to stick on start up, when the key ignition is activated the throttle body barely moves to its closed position setting, which allows enough air in to start the engine. When this sticks it has trouble starting. When this is the case you can usually depress the gas pedal slightly to get it to fire right up.

Customer: replied 1 year ago.
the vehicle when it starts, it runs. no issues when running, just the long hard start
Customer: replied 1 year ago.
also, when it's hard starting, the brakes pedal gets hard
Customer: replied 1 year ago.
hi i am looking at the cayenne Porsche we have a durametric diagnostic cable it doesn't pick up any main errors
Customer: replied 1 year ago.
this problem is intermittent sometimes it starts ok once the engine has run previously on mornings also but the brake pedal has to be soft we checked the fuel pump the glow plugs changed the battery checked the filter put diesel treatments in the tank it worked a little better for a short period but still hard starting
Expert:  Jake replied 1 year ago.

Sorry i was tied up for awhile.

When the brake pedal is hard, are you still able to use the accessories from the keyless functions? meaning the key is detected and you can still operate the radio etc?

Or does it seem like the vehicle is completely shut down?

Customer: replied 1 year ago.
we have those functions
Expert:  Jake replied 1 year ago.

Ok, thanks for clarification.

With your exact symptoms, it is usually caused by vacuum leak in the brake booster. Follow the vacuum line from the booster and inspect it for cracks, pay close attention to the are where the factory heat shrinks the tube on the end fitting because this is the most common location for leaks. In the mean time, you will have to press hard on the pedal Since have no vacuum assist for your power brakes.

Expert:  Jake replied 1 year ago.

If you need further assistance just ask.

If not be sure to leave a kind rating so that the site credits me for my time.