This has happened to my wife's car twice in the last couple of months, once to her and once to me (today). Traveling at highway speeds in 5th gear we've noticed a sudden loss of acceleration. When it has happened, pushing on the accelerator does nothing- the engine speed as measured by the RPM gauge was still high but it couldn't be increased. Both times, we pulled over, stopped and discovered that the car was idling fine but there was no response from the accelerator. Pushing on the pedal did nothing. She shut the car off on the side of the highway, restarted and the accelerator worked again.

I stopped and then nursed the car from an off ramp a short distance to a gas station feathering the clutch as the car was still idling just fine. I then shut the car off, restarted and the accelerator worked again for me also.

It's a 2003 R50 with 99,000 miles on it as of right now. We usually run high quality gas, 89 octane. I don't think it's the fuel as the car doesn't stumble, the throttle just has no effect.

There were no warning lights thrown when these incidents happened; I do have a MiniMania OBD II scanner that I could use to check for codes, if there's a chance it threw one.

Thanks-

Val

 

EML light? That's a tough one. It's drive-by-wire, so I guess, trying the dead-mouse theory, check the connector at the throttle body. It sounds like it may be the servo that actuates the throttle, but without a code, it's hard to say.

 

Mine did that last summer as well only mine is an 05 S, was cruising along at 75 MPH with the speed control activated then engine speed dropped to idle, accelerator had no resistance at all, pulled over and tried to rev motor, nothing.
Turned the car off, restarted worked fine only the speed control would not work. I went ahead and drove the 300 miles home with no other issues, no lights or codes showed up and the next time I was on the highway and tried to use the speed control it worked just fine.

It is a real head scratcher for sure.