Engine Trouble

[Andyni]

I need any advice that you may be able to give.

This morning after just pulling on to a roundabout I had no throttle response and the car coasted to a stop. The engine ran for a while and then died with the throttle fully down. Then latter this evening on two separate occasions the car lost all throttle response. After stopping the car and putting it into park the idle speed was erratic bouncing up and down. On all three occasions today turning off the engine and restarting the car worked.

Does anyone have any idea what the problem could be?

 

[Birdman]

Whenever something really odd happpens to the engine/gearbox they word is: check the MAS is functioning correctly.

 

[Andyni]

Should I just disconnect the MAS?

 

[Parrot of Doom]

Is the accelerator cable and the linkage all ok? Seems odd that there was no response at all when you floored it. Perhaps the little throttle pot is dicky.

 

[Birdman]

Should I just disconnect the MAS?

Yes. If no change then look elsewhere, I guess.

 

[grober]

If you have an electronic throttle then its possible the sender unit or throttle actuator has a problem. Not familiar with your model in detail sorry.

 

[Andyni]

Okay, I tried disconnecting the MAF but still had to restart the car three times on my way to work this morning (38 miles). So not the MAF. Will check out the throttle system. Many thanks

 

[DrNick]

Okay, I tried disconnecting the MAF but still had to restart the car three times on my way to work this morning (38 miles). So not the MAF. Will check out the throttle system. Many thanks

Surely this proves nothing?
If the MAF is broken and open circuit then its already disconnected, so unplugging it will have no effect!

 

[Parrot of Doom]

Well usually its a good way to check if the MAF is intermittent, and not completely faulty.

 

[Birdman]

Surely this proves nothing?
If the MAF is broken and open circuit then its already disconnected, so unplugging it will have no effect!

If it's open circuit the engine runs OK most of the time. The MAF obviously isn't open circuit.

 

[Dieselman]

Surely this proves nothing?
If the MAF is broken and open circuit then its already disconnected, so unplugging it will have no effect!

It doesn't work like that.
The heated element is heated and the thermistor feeds a low feedback voltage to the MAF pcb. This low voltage is then amplified and a higher voltage 0-5v is fed to the ECU.