Slow Acceleration. Ecm/ecu Issue?

[Ben99]

Hi
I have noticed in the last few days that my 2001 Auto is slow accelerating especially when moving from stationary. It sounds like its taking time to switch to higher gears as I need to rev it a bit more to get it going. I had a full service done 6 months ago.
I took it to a local garage to check the transmission oil and they confirm its not low but suggests it could be the transmission box which may need checking out.
Its only done 50K miles.

I have read it could be a common fault with this model and the ECM/EDU will need repairing.

Any advice as i'm clueless?

Thanks

[FROSTYBALLS]

If it is the ECU, have a look at http://www.ecutesting.com/toyota.html

[Ben99]

If it is the ECU, have a look at http://www.ecutesting.com/toyota.html

Thanks

I dont feel confident in taking it out and shipping myself.

I have also found this place who will install it for you but not sure how good they are:

http://www.rav4ecurepair.co.uk/

[FROSTYBALLS]

I know that other Rav 4 members have used ecutesting previously with good results. If you have an independent mechanic/garage, they should be able to take the ecu out for you. Don't know rav4ecurepair, so can't comment on how good they are.

[Ben99]

Is it better to order a new Ecu and fit it rather than send off mine for replacement?

I know it will cost a bit more but are there any other disadvantages to a new unit?

Thanks

[firemac]

Is it better to order a new Ecu and fit it rather than send off mine for replacement?

I know it will cost a bit more but are there any other disadvantages to a new unit?

Thanks

Compared to a repair by ECUTesting (circa £250 - £300) + special del'y postage, a new ECU from Toyota will be uneconomical (£1K +??). The removal & refitting issues will be exactly the same. The ECU is simply a printed circuit with software drives mounted. All ECUT do is test the unit and if it's faulty, they will re-load the latest s/w and re-test. They have a brilliant reputation and have sorted out many forum members here. They turn the ECU around in about 5 working days, which is pretty good. Bear in mind though that they might not find any fault in which case they only charge a testing fee but at least that will eliminate one possible source of your problem.

As Mike says, get the garage who service your car to remove/refit the ECU for you. It's definitely the way to go. ECUT will give you a discount (10%, I think) if you tell them your a member of TOC when you book it with them.

Good luck & let us know how you get on.

[Ben99]

Hi all

Thanks for all the advice.

I did in the end took out the ECU myself after watching You Tube videos and sent it off to ECU Testing who charged me approx £220 after discount.

The unit arrived back fast in 3 working days and after fitting it back, I took the car to my local garage to have the Transmission Oil changed also.

The car drove great for the first 2 weeks, almost like new and smooth. However, in the past week, I have noticed it has become sluggish and taking time to pick up speed but its not having any of the original symptoms of jerking etc

Any ideas what is causing this sluggish performance even though the ECU was repaired and Transmission oil was changed?

Thanks

[firemac]

Hi all

Thanks for all the advice.

I did in the end took out the ECU myself after watching You Tube videos and sent it off to ECU Testing who charged me approx £220 after discount.

The unit arrived back fast in 3 working days and after fitting it back, I took the car to my local garage to have the Transmission Oil changed also.

The car drove great for the first 2 weeks, almost like new and smooth. However, in the past week, I have noticed it has become sluggish and taking time to pick up speed but its not having any of the original symptoms of jerking etc

Any ideas what is causing this sluggish performance even though the ECU was repaired and Transmission oil was changed?

Thanks

That's very unfortunate, Ben. However if the car ran well for two weeks, it would appear that your ECU problem was cured, especially if you are not now getting the "ECU failure" symptoms. As far as I know there has only been one instance on this forum of an ECUT re-flash failing and having to be done again - and in that case, after the second re-flash, it was fine. Remember that ECUT give a lifetime warranty on their work so you'll be OK even if it is a repetition but, as you say, it doesn't sound like it.

Does your car have an OBD port for connecting an electronic reader? The port is under the dash below the steering column. It is a plastic female socket with lots of little connectors in rows inside it. If so you can either get your garage to plug in their diagnostic reader to see if there are any fault codes existingthat will give a clue as to the problem. Alternatively you can buy a reader on the internet for anything from about £15, which will allow you to check yourself before involving the garage. I'm not positive but seem to recall reading on here that early 4.2s were not OBD compliant but I don't know the exact dates.

Hopefully it is just a coincidence that something minor has occurred which is giving you this problem. Has anything else changed/occurred recently that may have caused a problem, i.e. using a different petrol or station, any starting problems, a recent service, etc? Is the car due a service now? Does it rev up cleanly when stationery in N or P? Try to eleiminate these simple issues first before getting into worrying about anything bigger.

[Ben99]

Thanks for the advice firemac.

Yeah i really dont want to send off the ECU back again as it was quite a struggle taking it out.

I normally stick to Sainsburys unleaded petrol so not sure if the last fill up was a bad batch so i will wait until my next fill to see if that makes a difference.

I do have a OBD port so may get one if theres no improvement.

The car currently does need at least 3000rpm before it automatically switches in the lower gears so not sure if thats normal but its def feels slower and need more power uphill than in the past.

Thanks

[firemac]

Thanks for the advice firemac.

Yeah i really dont want to send off the ECU back again as it was quite a struggle taking it out.

I normally stick to Sainsburys unleaded petrol so not sure if the last fill up was a bad batch so i will wait until my next fill to see if that makes a difference.

I do have a OBD port so may get one if theres no improvement.

The car currently does need at least 3000rpm before it automatically switches in the lower gears so not sure if thats normal but its def feels slower and need more power uphill than in the past.

Thanks

Try running it only on Shell V-Power Nitro+ (or BP's premium petrol) for a few tankfuls. There are so many question marks over supermarket fuel that it is a false economy.

Also, check that all the vacuum pipes on th engine are sound. They should be squeezable but firm with no splits, cracks or holes. It could be that one of these is split and allowing too much air into the mixture resulting in lean running and the sort of problem you're experiencing. The vacuum pipe(s) is black and about 10-15 mm diameter and runs from the induction manifold to the breather in the engine block at the rear of the engine.

This is by no means not the only possible cause of your problem but it is an easy one to check.

[Ben99]

Thanks i'll check that.

Another thing is that i noticed the Power Steering more stiffer than usual so not sure if thats related to this too?

[BJB]

I have had exactly the same stiff Power Steering and the cause was a corroded engine earth strap. Replaced it and the car was like new. There are so many electronic items on modern cars that even slightly low voltages can have an adverse effect on all sorts of things. Easy to check and cheap to replace and it may solve your problem.

Bryan

[firemac]

I have had exactly the same stiff Power Steering and the cause was a corroded engine earth strap. Replaced it and the car was like new. There are so many electronic items on modern cars that even slightly low voltages can have an adverse effect on all sorts of things. Easy to check and cheap to replace and it may solve your problem.

Bryan

Very good point, Bryan. It's worth a try but bear in mind that your car is a 4.3 & has elec power steering and Ben's is a 4.2 with a hydraulic system where the pump is driven by the serpentine belt when the engine's running.

Ben, if you can't get a new strap, try removing it from the engine & the chassis and give the cable end connectors and the earthing point on the chassis a good clean to bright metal with emery paper (the earth on the engine should be clean anyway but you could check). Re-connect and smear the area on the chassis with grease/waxoyl/etc. to keep moisture out. I can't see it having any effect on your PS issue but it will ensure that there is a good elec circuit for all the other electronics including the fuel injection, etc.