Engine Runs On

January 30, 2009

There is a periodic fault with the engine of my 2007 Rav XT4 2.2 D-4D. Occasionally, when lifting off the accelerator, the engine continues to 'run on' with the same level of revs. as before. This continues for about 200 yards before 'dying down' if you don't need to brake. This can be disconcerting and, I think, potentially dangerous. The car has been back to a main Toyota Dealer several times but they have been unable to diagnose any fault. Has anyone else experienced the same problem?

January 30, 2009

I am sure Anchorman will sort you out with a proper answer in a wee while..

In the mean time... I have noticed that my one has a sort of "stall -prevention" when I get off all of the controls, for example in second gear, the revs die right down and then go up again by some 2-300 RPMs and the car drives itself. I just assumed this is the computer protecting itself from stalling. I agree with Anchorman here, stalling a 2.2 D4D _is_ rather scary...

Is this what you mean or are the revs significantly higher?

Oh and welcome to the club! :)

January 30, 2009

Yes welcome to the club from me too!

Some cars are programmed to hold the revs while you change gear as it smooths out the change. In fact the RAV does not do that but it does have a damper for over-run. Try the following. First gear has the biggest engine braking affect however if you set off in first and take the revs right up to about 4000 and let your foot of quickly, instead of throwing you through the windscreen it will die down progressively to help drive smoothly. Because there is no physical link in the accelerator this is all done electronically - there is a potentiometer at the pedal which sends signals to the ECU.

Try the obvious things first. Just work the pedal with your hand and make sure it feels free and appears to come right back to the off (upper) position. Do it also when the fault occurs so if it seems to run on in the way you describe see if you can hook your toe under the pedal to make sure it has come back.

If none of those work it starts to get heavy and there will be a limit to what you can do next. The faults could be electronic so that would be the pedal potentiometer, the ECU (the main brain of the engine management), the EDU ( a separate brain that works the injectors according to info from the ECU) and the throttle body unit. These are none serviceable items and if they throw up an intermittent fault can be a complete @rse to find without special equipment. There are a few more physical things that could cause it. The throttle body has a flap inside that can stick. You could have a go at freeing this off but firstly you need to be competent and secondly if it sticks now it probably needs a new one under warranty. A leak around the intake side of the engine could cause it but it is hard to understand why it should do it intermittently. You can check this by taking off the engine cover (just pulls off) and lightly and briefly spraying WD40 around the back of the engine around the inlet manifold and pipes. Stay away from the exhaust and turbo and as an added safety precaution only do it when the engine is cold. If there is a leak the WD40 will be sucked in and the engine will rev. You can then home in on the leak. It is also possible for the damper on the turbo to stick and that may cause it.

The problem will be getting it to do it when it is at the dealer. You can do several things. Their hand held DLC3 tester is capable of doing live testing. If they hook it up and go for a long enough run it should pick up any faults that occur in real time. As with any computer it needs somebody who knows what they are doing - junk in, junk out so good luck with that! Ask to see the Zone Service Manager and tell him that it is a safety issue. It might encourage them to go through a process of elimination and change the most obvious. They may have heard something that the dealer hasn't and have a good idea where to start.

To be honest these are sometimes drawn out situations that only become easier if it does it all the time. While these components are usually very reliable they are expensive and Mr T won't want to throw money at it unless he thinks it is genuinely faulty.

Good luck mate.

January 31, 2009

Yes welcome to the club from me too!
Some cars are programmed to hold the revs while you change gear as it smooths out the change. In fact the RAV does not do that but it does have a damper for over-run. Try the following. First gear has the biggest engine braking affect however if you set off in first and take the revs right up to about 4000 and let your foot of quickly, instead of throwing you through the windscreen it will die down progressively to help drive smoothly. Because there is no physical link in the accelerator this is all done electronically - there is a potentiometer at the pedal which sends signals to the ECU.
Try the obvious things first. Just work the pedal with your hand and make sure it feels free and appears to come right back to the off (upper) position. Do it also when the fault occurs so if it seems to run on in the way you describe see if you can hook your toe under the pedal to make sure it has come back.
If none of those work it starts to get heavy and there will be a limit to what you can do next. The faults could be electronic so that would be the pedal potentiometer, the ECU (the main brain of the engine management), the EDU ( a separate brain that works the injectors according to info from the ECU) and the throttle body unit. These are none serviceable items and if they throw up an intermittent fault can be a complete @rse to find without special equipment. There are a few more physical things that could cause it. The throttle body has a flap inside that can stick. You could have a go at freeing this off but firstly you need to be competent and secondly if it sticks now it probably needs a new one under warranty. A leak around the intake side of the engine could cause it but it is hard to understand why it should do it intermittently. You can check this by taking off the engine cover (just pulls off) and lightly and briefly spraying WD40 around the back of the engine around the inlet manifold and pipes. Stay away from the exhaust and turbo and as an added safety precaution only do it when the engine is cold. If there is a leak the WD40 will be sucked in and the engine will rev. You can then home in on the leak. It is also possible for the damper on the turbo to stick and that may cause it.
The problem will be getting it to do it when it is at the dealer. You can do several things. Their hand held DLC3 tester is capable of doing live testing. If they hook it up and go for a long enough run it should pick up any faults that occur in real time. As with any computer it needs somebody who knows what they are doing - junk in, junk out so good luck with that! Ask to see the Zone Service Manager and tell him that it is a safety issue. It might encourage them to go through a process of elimination and change the most obvious. They may have heard something that the dealer hasn't and have a good idea where to start.
To be honest these are sometimes drawn out situations that only become easier if it does it all the time. While these components are usually very reliable they are expensive and Mr T won't want to throw money at it unless he thinks it is genuinely faulty.
Good luck mate.

Many thanks for your help. Next stop local Toyota Dealer - again!

January 31, 2009

I am sure Anchorman will sort you out with a proper answer in a wee while..
In the mean time... I have noticed that my one has a sort of "stall -prevention" when I get off all of the controls, for example in second gear, the revs die right down and then go up again by some 2-300 RPMs and the car drives itself. I just assumed this is the computer protecting itself from stalling. I agree with Anchorman here, stalling a 2.2 D4D _is_ rather scary...
Is this what you mean or are the revs significantly higher?
Oh and welcome to the club! :)

Many thanks. I have now heard from 'Anchorman.'

February 5, 2009

I am sure Anchorman will sort you out with a proper answer in a wee while..
In the mean time... I have noticed that my one has a sort of "stall -prevention" when I get off all of the controls, for example in second gear, the revs die right down and then go up again by some 2-300 RPMs and the car drives itself. I just assumed this is the computer protecting itself from stalling. I agree with Anchorman here, stalling a 2.2 D4D _is_ rather scary...
Is this what you mean or are the revs significantly higher?
Oh and welcome to the club! :)
Many thanks. I have now heard from 'Anchorman.'

DID YOU SORT OUT THE PROBLEM ? AS I AM HAVING THE SAME PROBLEM < I HAVE ACTUALLY TRAVELLED OVER A MILE AT 30 MPH WITHOUT TOUCHING THE ACCELERATOR< SERVICE MANAGER RECONS "HE CANT FAULT IT"