3.4l V6 surges at idle

[Clint330ci Junior Member Find all posts View Profile Close Clint330ci]

Hi guys
i have looked through the search and couldnt find this one -i recently bought a ute for my business. Its a 2002 hilux dualcab running the prado 3.4l v6.(i know its detuned for the scary handling of the hilux!) and is an Auto and has done around 100k.
Its dual fuel, lpg -unleaded. I noticed it surges at idle - slowly and consistently goes up and down around 100-250 rpm (its not the aircon kicking in!) at idle - it does this on both gas and unleaded.
Thought it might be MAF (and it might be) but it has heaps of power and drives really smoothly (for a hilux!) - its not a problem and just concious it may become one if not rectified :-)
Any help would be appreciated

cheers
Clint

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: 3.4l V6 surges at idle

Hi Clint,

The cheap:
- Intake air leak
- Spark plugs
- Clean airflow sensor (As you said)
- Idle control valve (clean)
- Air/fuel mixture too rich (check emisson control valves and hoses etc)

The expensive:
- Low compression
- Faulty in air flow sensor
- Faulty idle control valve

Hopefully a cheap fix!!! Good luck :wink:

Mick

[Clint330ci Junior Member Find all posts View Profile Close Clint330ci]

Re: 3.4l V6 surges at idle

hi mate
great thanks -might work through the cheap list first!!! :mrgreen:

There is a special "cleaner" that you buy for the MAF -correct?
cheers
Clint

[fishfinder Advanced Member Find all posts View Profile Close fishfinder]

Re: 3.4l V6 surges at idle

could also be coolant sensor

[MickL Addicted PP Member Find all posts View Profile Close MickL]

Re: 3.4l V6 surges at idle

Could be ECU fault too (idle control) - add to expensive list :wink:

There is a special "cleaner" that you buy for the MAF -correct?

Yes, CRC do a specific "Airflow Sensor Cleaner", but I think most people use "Contact Cleaner" without any problems.

Part number; CRC05110



Mick

[joffy4819 Junior Member Find all posts View Profile Close joffy4819]

Re: 3.4l V6 surges at idle

Check your MAS (mass airflow sensor). Mine was working within tolerances but was dirty. After cleaning with CRC CO cleaner(check other posts about MAS issues) Preformance has returned. Easy way to check is to disconect MAS and take it for a drive. If MAS is dirty, a $30 can of crc is a cheap fix. If you have to replace sensor, your can of crc will come in handy to use at every service to maintain preformance.