Revs cutting out- no warning lights

[jack roberts]

I have a Toyota Avensis 2008 estate with manual transmission and it runs on petrol.

I bought the car in 2021 with 83471 miles on the clock.  I’m based in London and after doing a couple of weekend trips not too far out of London, the car started acting up.

First instance was when driving back to London from Folkestone- I was cruising in 5^th gear around 70mph when revs were lost on the motorway for a couple of seconds before returning to normal.  I thought I had just eased up on the pedal too much, but the closer I got to London with roundabouts and lights forcing me to change gears, revs would completely vanish- despite putting the gas pedal all the way down! Revs would suddenly return aggressively but cut out next to 3000 in second gear and above. 

It was a pretty stressful drive getting back home- bunny hopping away from lights and revs being erratic; either way high or not there at all.  I had no warning lights appear on the dash throughout all of this, which was odd and had me question my driving!

I did some research myself and ran through possible issues- Cleaned the MAF sensor (was a little sooty), checked spark plugs (all clean), checked air filter (like new) and topped up the coolant as it was rather low.  I took the car to a nearby garage and they ran a computer diagnostic check that brought nothing up.

A couple of months later I did a decent road trip- from London to Hampshire and back a couple of days later, a night in London, then on to Cambridge for a night before making the trip up to the lake district.  The car had no issues on this journey, so I thought all my tinkering had worked.

However, when it came to driving back to London from the lake district in one journey, the issue returned about 2 hours away from London!  Revs completely cutting out near 3000 in any gear and struggling to get them back over 2000 from there.  Revs were sluggish when/ if they came back- no matter how far down the gas pedal was.

I waited on the hard shoulder of the M1 for an hour before the AA requested I get to the closest fuel station.  Getting there was a trek with the engine still acting gammy.  When the mechanic pitched up he checked the spark plugs- still fine, the air filter and hoses all ok.  Throttle body was clean after removing the intake hose and checking the butterfly flap.  Coolant levels fine, engine oil fine and Battery was good. He even ran a computer diagnostic check that once again brought nothing up and I had no warning lights come on throughout all of this!  After weighing up my recovery options, I made the decision to continue the journey and luckily made it back home safe- now well versed with the sound of each car’s horn I encountered on that last stretch…

Since then, I have checked the EVAP purge valve and it is ticking away as it should and not leaking in any way.  I have also added injector head cleaner to my fuel.  

I have had the issue return a couple of times since this, albeit not as aggressive.  Still no warning lights come on whenever the car is going through this.

I plan on taking my car to a proper Toyota garage to get it remedied but would appreciate if anyone has an idea of what might be going on so that I can request that the mechanics zero in on the issue.  It would be great if I can sort it out myself and avoid that cost.  I don’t believe the issue to be caused by E10 petrol, as it started happening when I was exclusively using E5 and my car has a 3ZZ-FE engine, which is compatible with E10.  Hopefully I didn't purchase a lemon!

Any relative advice would be appreciated! Cheers much

Edited January 23, 2022 by jack roberts
poor grammar

[2009joe]

1 hour ago, jack roberts said:

I have a Toyota Avensis 2008 estate with manual transmission and it runs on petrol.

I bought the car in 2021 with 83471 miles on the clock.  I’m based in London and after doing a couple of weekend trips not too far out of London, the car started acting up.

First instance was when driving back to London from Folkestone- I was cruising in 5^th gear around 70mph when revs were lost on the motorway for a couple of seconds before returning to normal.  I thought I had just eased up on the pedal too much, but the closer I got to London with roundabouts and lights forcing me to change gears, revs would completely vanish- despite putting the gas pedal all the way down! Revs would suddenly return aggressively but cut out next to 3000 in second gear and above. 

It was a pretty stressful drive getting back home- bunny hopping away from lights and revs being erratic; either way high or not there at all.  I had no warning lights appear on the dash throughout all of this, which was odd and had me question my driving!

I did some research myself and ran through possible issues- Cleaned the MAF sensor (was a little sooty), checked spark plugs (all clean), checked air filter (like new) and topped up the coolant as it was rather low.  I took the car to a nearby garage and they ran a computer diagnostic check that brought nothing up.

A couple of months later I did a decent road trip- from London to Hampshire and back a couple of days later, a night in London, then on to Cambridge for a night before making the trip up to the lake district.  The car had no issues on this journey, so I thought all my tinkering had worked.

However, when it came to driving back to London from the lake district in one journey, the issue returned about 2 hours away from London!  Revs completely cutting out near 3000 in any gear and struggling to get them back over 2000 from there.  Revs were sluggish when/ if they came back- no matter how far down the gas pedal was.

I waited on the hard shoulder of the M1 for an hour before the AA requested I get to the closest fuel station.  Getting there was a trek with the engine still acting gammy.  When the mechanic pitched up he checked the spark plugs- still fine, the air filter and hoses all ok.  Throttle body was clean after removing the intake hose and checking the butterfly flap.  Coolant levels fine, engine oil fine and battery was good. He even ran a computer diagnostic check that once again brought nothing up and I had no warning lights come on throughout all of this!  After weighing up my recovery options, I made the decision to continue the journey and luckily made it back home safe- now well versed with the sound of each car’s horn I encountered on that last stretch…

Since then, I have checked the EVAP purge valve and it is ticking away as it should and not leaking in any way.  I have also added injector head cleaner to my fuel.  

I have had the issue return a couple of times since this, albeit not as aggressive.  Still no warning lights come on whenever the car is going through this.

I plan on taking my car to a proper Toyota garage to get it remedied but would appreciate if anyone has an idea of what might be going on so that I can request that the mechanics zero in on the issue.  It would be great if I can sort it out myself and avoid that cost.  I don’t believe the issue to be caused by E10 petrol, as it started happening when I was exclusively using E5 and my car has a 3ZZ-FE engine, which is compatible with E10.  Hopefully I didn't purchase a lemon!

Any relative advice would be appreciated! Cheers much

by chance dude im not sure if u can see this threw toyota techstream software do you think is there a fault with the Electronic Throttle Control  system maybe the peddle itself 

[jack roberts]

Cheers Joe,

Toyota Techstream, first time hearing about this but sounds like a good lead!  Have you used the software yourself?  Is it set apart from typical car diagnostic programs in that it is specialized for Toyota's?

Thanks 

[2009joe]

3 minutes ago, jack roberts said:

Cheers Joe,

Toyota Techstream, first time hearing about this but sounds like a good lead!  Have you used the software yourself?  Is it set apart from typical car diagnostic programs in that it is specialized for Toyota's?

Thanks 

yep i have it but think its you can load it one time encase you use your laptop i bought a cheap ssd from eBay think about 200gb and well i loaded new windows 32bit on there just basic windows 7 32 bit and didnt connect to internet or nothing then i loaded techstream on it then put in the code so techstream works great piece of kit u can turn off annoying dings dings etc and well see whats wrong .i bought mine from eBay think this is one you need 

https://www.ebay.co.uk/itm/303933863223?hash=item46c3deb537:g:M6cAAOSwaxtgXHsx

 

so i have a spare ssd and if need to use it i just swap over ssd on my laptop and im good to go then when finished i just take it out again and put in my other ssd i use and nothing has changed 

[Red_Corolla]

When you say the revs cut out, do you mean the rev counter drops to zero, or do you mean you lose power as though you've taken your foot off? If you're losing the rev counter completely then the crank sensor might be the culprit, but it's better not to speculate without knowing all the facts.

[jack roberts]

Cheers much for that info Joe, mad cyberpunk advice!  Will have to try it out.

Hiya Red_Corolla, in answer to your question- yes, both things happen; power is lost as though my foot wasn't on the pedal at all. The engine basically returns to idle, even when cruising at speed.  The rev counter drops down to match this.  When this happens, I've dropped gear to try and remedy quick- but even with pumping the gas pedal, the engine reluctantly returns to running with low power and with low engine revs. Usually dropping down another gear gets the engine revs back- they jump way up the counter and when I ease off acceleration to avoid redlining, power drops quickly and it is hard to find a position on the gas pedal to maintain responsible engine revs.  

So the issue is the engine power suddenly disappearing from a steady cruise with engine revs being erratic thereafter.  The rev counter is only visually showing how the engine struggles, I don't think the rev counter is at fault.  This happens on journeys over around 50/ 60 miles.

I hope that describes my issue better, thanks for taking the time!

[Notoyboy]

Starting with the simplest, I presume there's a fuel filter somewhere.  Is that OK?  Had you a diesel, I'd query whether you might have water in the fuel, but I'm not so conversant with petrol engines.

[2009joe]

1 hour ago, jack roberts said:

Cheers much for that info Joe, mad cyberpunk advice!  Will have to try it out.

Hiya Red_Corolla, in answer to your question- yes, both things happen; power is lost as though my foot wasn't on the pedal at all. The engine basically returns to idle, even when cruising at speed.  The rev counter drops down to match this.  When this happens, I've dropped gear to try and remedy quick- but even with pumping the gas pedal, the engine reluctantly returns to running with low power and with low engine revs. Usually dropping down another gear gets the engine revs back- they jump way up the counter and when I ease off acceleration to avoid redlining, power drops quickly and it is hard to find a position on the gas pedal to maintain responsible engine revs.  

So the issue is the engine power suddenly disappearing from a steady cruise with engine revs being erratic thereafter.  The rev counter is only visually showing how the engine struggles, I don't think the rev counter is at fault.  This happens on journeys over around 50/ 60 miles.

I hope that describes my issue better, thanks for taking the time!

by chance would would think its the  Electronic Throttle Control  at fault 

[jack roberts]

Heya Notoyboy, I thought the fuel filter could be at fault, but have not had the means to check it myself.

Joe, I'm beginning to think the same thing actually- your comment led me to this video and it sounds relative! Particularly how the video says 'the vehicle may be limited to second gear and not go any faster than 35mph.' Sounds like what I've been through!  Will have to check for faults on that part using a scan tool.

Sounds like a promising lead!  Thanks!

 

[2009joe]

8 minutes ago, jack roberts said:

Heya Notoyboy, I thought the fuel filter could be at fault, but have not had the means to check it myself.

Joe, I'm beginning to think the same thing actually- your comment led me to this video and it sounds relative! Particularly how the video says 'the vehicle may be limited to second gear and not go any faster than 35mph.' Sounds like what I've been through!  Will have to check for faults on that part using a scan tool.

Sounds like a promising lead!  Thanks!

 

possible could be  maybe a good scan tool will tell you i bought myself a autel md802 all systems with lifetime update scanner which i like it i think the ones now only cover 1 car and you have to buy extra if you have other cars i got my scan tool a few years back so my all system one has the  lifetime updates 

[Bernard Foy]

Another similar simple explanation, a dirty fuel tank.

[jack roberts]

Cheers Bernard.  I've got an MOT due soon so will take my car to a proper Toyota Garage and bring that up too- it was something I considered, just didn't have the means to check myself.

Thanks for the advice so far guys!

[Konrad C]

Hi Connor, I know of a Toyota like specialist in Sidcup - http://www.tech-one.co.uk/ if you are in South London, or A decent garage that can diagnose and hopefully fix the problem. The main dealers will be more expensive. 

After reading the whole thread, there are so much probable causes. It could be electronic at either throttle pedal or throttle body, cam or crank sensors, fuel issues, blocked air filter, sparkplugs or coil packs, or the ECU. Check the wiring and connections for damage. Yes diagnostics might find the problem. One possibility could be a collapsed or blocked catalytic convertor! It could be something simple and cheap or an expensive fix. Let's hope it is cheap and simple.
  

[jack roberts]

Heya Konrad, thanks for the link on that garage, very useful!

Yes, I did a lot of troubleshooting and checking out what I could get my hands on in the car, but this conversation thread has been useful in bringing things up I missed/ didn't know about.  I'll let the mechanics know what I haven't been able to check on myself so that they can assess the points everyone here has mentioned.

Hopefully is cheap indeed, and hopefully I can get this problem sorted! 

[Red_Corolla]

Like Konrad says, you won't get to the bottom of it without reproducing the fault while looking at the data because there's too many variables. With professional diagnostic equipment, they can view air flow, fuel pressure, misfire count, throttle position desired Vs actual etc etc. all as live readouts. That sort of thing should narrow down the root cause, just be wary of establishments that replace parts based on educated guess and expect you to pay whether it cures the fault or not. A lot of places operate that way.

[jack roberts]

Hi Red,

When my vehicle was having the issue on the M1 and a mechanic was sent out to check, I hoped we would get a result as the fault was in full swing. Alas, he didn't pick anything up!  Not sure if he was missing something or didn't check the correct areas, but computer said NO...

I am writing to Tech One now and mentioned that my suspicions are a faulty throttle control system (with concerns over catalytic converter and possible manky fuel tank) and will see what they have to say.  This conversation has been useful for me to learn what may be at fault, so if they mention anything abstract from that, I'll tread cautiously! Cheers again

[Red_Corolla]

5 hours ago, jack roberts said:

Hi Red,

When my vehicle was having the issue on the M1 and a mechanic was sent out to check, I hoped we would get a result as the fault was in full swing. Alas, he didn't pick anything up!  Not sure if he was missing something or didn't check the correct areas, but computer said NO...

I am writing to Tech One now and mentioned that my suspicions are a faulty throttle control system (with concerns over catalytic converter and possible manky fuel tank) and will see what they have to say.  This conversation has been useful for me to learn what may be at fault, so if they mention anything abstract from that, I'll tread cautiously! Cheers again

That is unfortunate. In the guy's defense, I would say that it's a difficult challenge for a roadside breakdown technician. They work on all kinds of vehicles with limited access to information resources and pressure to get the customer moving as fast as possible so they can move on to the next one. A good garage with the right equipment and access to the right resources should be able to get to the bottom of it, but they will need time with the car to reproduce it.