I have a problem with a 2000 S70 with 150,000 miles. When the key is turned quickly the car starts and runs with no power and won't rev above 1200. If key is paused at position II for 5-10 secs the car starts and runs with no problem.

Any ideas on what would cause this?

Something is dirty and slow to respond. What is the idle speed after a 'quick' start? If you wait for 5-10 seconds after 'quick' start, do things get to normal without touching the gas pedal?

I suggest you try cleaning the throttle body for starters. If the pump is still 'priming' for 5 seconds after you turn the key to position II, suspect a dirty fuel filter that is restricting flow.

Klaus
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Did you do your Random Act of Kindness today?

The condition doesn't always occur but the last time it happened:

- the engine ran rough like it was missing on one cylinder
- idle dropped to about 500 - 600
- I drove about 1000 yards and it was like the throttle was disconnected. RPM would only go up to about 1200 even though the pedal was pushed to the floor. The engine didn't miss or backfire like it was getting to much gas during this time.
- car would only travel about 5 miles per hour on flat ground.

If the condition happens again what troubleshooting checks do you recommend?

Thanks,
Tod

You have a wireless throttle, so the first suspect would be the ETM. If there are no error messages or check engine light, that means all communications to the engine computer are good. Pushing the gas pedal does no good if the ETM does not respond.

There is a 'cheaper' than the dealer ETM replacement at Xemodex.com, if that is the problem. Having the key in posII for more than 5 sec might just be what is needed for the ETM to ready itself for engine start.

Klaus
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Did you do your Random Act of Kindness today?

Thanks for the info. I'm going to clean the throttle body and all connections today.

Tod