Hesitation on accelerating

[ste_johnstone]

I have a strange issue with my Rav4 2.0 XT3 2003 that I'm hoping someone might be able to help me with.

Hesitation on acceleration and fluctuating idle, no fault codes.

Cleaned the MAF, no change. Replaced the MAF with a brand new Denso (OEM) MAF, no change. Unplug the MAF and the car it runs absolutely perfectly until 3k rpm then it will cut out and throw a fault code, as expected.

So, everything is pointing to the MAF. Is it possible the wiring to the MAF could be faulty? Could I have received a faulty MAF as a replacement? 

I've read IAC or fuel filter could be to blame but that seems a little unlikely if it runs perfect when the MAF is unplugged.

The only other time a code has appeared was the lambda sensor however once cleared everything went back to normal hesitation. I'm thinking its not the lambda because emissions etc were all on point.

Any thoughts or ideas would be greatly appreciated.

Steve

[152bobby]

I get the hesitation acceleration issue on my 4.3 and I have learned to live with it.

However, it can prove to be dangerous at roundabouts etc.

I just wish the auto gearbox worked as well as it does when using the paddles !!

[deano20010]

I have hesitation on mine as well when pulling off of learned to give her more throttle but mine is to do with 2x broken Oxygen Sensors but they will be fixed today so lets hope that fixes it.

[152bobby]

I get the hesitation acceleration issue on my 4.3 and I have learned to live with it.

However, it can prove to be dangerous at roundabouts etc.

I just wish the auto gearbox worked as well as it does when using the paddles !!

 

I would expect this pulling away hesitation to be only with automatics and not manual gearboxes !!

[IanML]

On 12/1/2017 at 7:45 PM, ste_johnstone said:

I have a strange issue with my Rav4 2.0 XT3 2003 that I'm hoping someone might be able to help me with.

Hesitation on acceleration and fluctuating idle, no fault codes.

Cleaned the MAF, no change. Replaced the MAF with a brand new Denso (OEM) MAF, no change. Unplug the MAF and the car it runs absolutely perfectly until 3k rpm then it will cut out and throw a fault code, as expected.

So, everything is pointing to the MAF. Is it possible the wiring to the MAF could be faulty? Could I have received a faulty MAF as a replacement? 

I've read IAC or fuel filter could be to blame but that seems a little unlikely if it runs perfect when the MAF is unplugged.

The only other time a code has appeared was the lambda sensor however once cleared everything went back to normal hesitation. I'm thinking its not the lambda because emissions etc were all on point.

Any thoughts or ideas would be greatly appreciated.

Steve

If the MAF/wiring was a problem, you would expect a fault code (I take it you got that when when you unplugged the MAF).

It does sound like another sensor could be to blame.  My money would be on CTS, then IAT.

[ste_johnstone]

8 hours ago, IanML said:

If the MAF/wiring was a problem, you would expect a fault code (I take it you got that when when you unplugged the MAF).

It does sound like another sensor could be to blame.  My money would be on CTS, then IAT.

Thanks very much for your response, what are CTS and IAT if you don't mind me asking?

[IanML]

Coolant temperature sensor and Inlet air temperature sensor.

[ChrisG-007]

I have a 2013 Rav4 and began experiencing some hesitation. Having just over 70k miles on it, thought about changing the transmission fluid/filter and differential. The dealer said I'm good until 100k miles but did not address the hesitation.  Today I received a Torque Converter Warranty extension from 60,000 to 150,000 miles to correct shudder issues between 20 and 50 MPH.  I now have the answer to the hesitation issue.  The letter does not indicate which model years it affects but worth a look.

[deano20010]

unplug your lambda sensor 2x at top start her up if engine light comes on stop engine plug them back in

[ste_johnstone]

Thanks for everyone's responses. I've got a few things to be trying so I'll keep you updated on my progress. Thanks again 

[ChrisG-007]

The dealership confirmed it is torque converter issue and it took a ride along with one of their mechanics.  Scheduled for repair on the 5th.