Flat Acceleration

[Roly]

Hi all

loving my RAV at the moment, great fun to drive but I have noticed (especially when first driven and still warming up) that I get times when the acceleration seems to falter from start and then surges forward. Happened this morning when I pulled out of my drive and had to accelerate harder to miss a car (am on a blind bend), put my foot down, car hesitated then rushed forward and promptly did the same in second. Car wasn't fully warm but only just off the running temperature - usually let it warm up a bit before I attempt to get out of the drive for reason above. Doesn't do it all the time but more so recently, use the same fuel generally, but am doing short journeys at the moment around local villages.

Any ideas welcomed

2001 4.2gx 2.0L VVTi Petrol

[anchorman]

Old spark plugs have the habit of breaking down under load - especially when cold. The service period is very long but if you have not had any for a long time I would give it a go before you start looking too hard. Take care that they may specify platinum or irodium tipped and trust me it will run much better on them than regular copper cored but they may be expensive.

Normally fuel injected vehicles don't suffer from flat spots.

Good luck

[Roly]

Thanks Anchorman

Wondered about plugs though when I bought the car it had just had a major service according to the dealer - I'll bet that didn't include replacing the plugs though! Will take them out and have a look to see if they're clean or not. Any suggestions for make when replacing...NGK, Bosch??

Cheers

[anchorman]

Thanks Anchorman

Wondered about plugs though when I bought the car it had just had a major service according to the dealer - I'll bet that didn't include replacing the plugs though! Will take them out and have a look to see if they're clean or not. Any suggestions for make when replacing...NGK, Bosch??

Cheers

I prefer NGK but more important is to make sure you get the right type of plug. Any decent spares supplier should advise you but from memeory they should be platinum tipped.

The dealers will stick rigidly to the service shedule so if it had done say 50k of a 60k service interval then they won't have been changed. For what it will cost it is worth a try. Also, try to go to a good motor factor rather than somebody like Halfords who will skin you alive.

Incidentally, you can't tell anything by looking at them. If they have got to the point where they are breaking down under load it will be in the resistance, continuity or insulation of the plug. The only thing that would be obvious would be if there are black marks on the porcilain ribs (which are there to deter flashover down the side of the plug). This would indicate high resistance and the spark has been tracking past the ribs.

All the best.

[Roly]

Just checked the service record - 60k done although car was only at 47k...only put on 2k since buying it. On the 60k schedule would they replace the plugs? Was never given a worksheet so not sure what was done.

Another thought - could it be dirty injectors as I'm only doing short journeys?

cheers

[anchorman]

Just checked the service record - 60k done although car was only at 47k...only put on 2k since buying it. On the 60k schedule would they replace the plugs? Was never given a worksheet so not sure what was done.

Another thought - could it be dirty injectors as I'm only doing short journeys?

cheers

They should have been done but who knows. If it was done by a Toyota dealer I am surprised that they have done a 60k at 48k but if they did phone and ask because they usually keep a good record. If it was done by an independant then the chances are they will have put copper cored plugs in and that could well be the answer to your problem.

If you are putting new ones in yourself you need to remove the plastic cover, and carefully remove each coil pack from above the spark plug. Sounds complicated but it is fairly straight forward.

Dirty injectors are not normally effected by temperature. You can add a bottle of injector cleaner to a full tank and it won't harm as a belt and braces.

Good luck