Funny idel

[Cachris]

Trouble shooting funny ideling. Only at low rpms, when driving perfect.

https://youtu.be/G_OvL6jAgLE


What do yo think?

Thanks Chris

[Dippydog]

Have you done/had done any work on it recently or did it just suddenly begin doing this?

[Cachris]

No nothing it just started after we bought it.

[Georgeandkira]

I cannot identify the bit of rhythm I hear but it's a far cry from real "hunting".

Please include year, mileage, relevant history with posts. How long have you owned it?

Try throwing in a bottle of a PEA cleaner before a stint of local driving. Chevron Techron concentrate is a good one.

Change the fuel filter. Clean the ETM. Are the spark plugs "in service" and of the correct type?

Is the air filter in OK condition?

[Dippydog]

The only time my P1 V70 has "hunted" was when I changed to contactless TPS and it was a lot more pronounced than yours is doing.I'd check/clean throttle body-it's only a few minutes work with carb cleaner and a toothbrush-and check for air leaks as a starting point.By how much is the rev counter fluctuating?

[Georgeandkira]

I thought of actual RPM numbers myself. A separate test tach might read better than the one in the dash.

Pre-test the toothbrush you'll use to see if it stands up to the carb cleaner you select.
You don't want to have to clean a bunch of plastic bristles from your ETM.

[Cachris]

So ok after looking at the engine I don't think it's going to be as easy as first thought. I'm going to guess it's going to be in all day job looks like I have to remove the fan to get to the throttle body.

Going to have to ask some stupid questions here.

1. Are the spark plugs underneath the top plate next to the injector cover?

2. Why does the air intake route to the front of the radiator and then come back?

[Dippydog]

The video is a little too quick for me,but on my P1 the throttle body is at the right hand end of the engine and is held on by 4 bolts and then there's the trunking from the air filter on the end of that-held on by a jubilee type clip.The wiring runs down behind the starter motor to a plug low down near bottom of fan shroud.I had to move starter motor to remove my throttle body[to get the wiring plug past it]when I changed to contactless.However when I cleaned the throttle body I left it in place and just removed the air trunking.As yours is a later car some things may have been altered over the layout on mine but would've thought throttle body could still be accessed without removing the fan?

[Cachris]

Thanks for all the info. I’m going to try and clean the throttle body this weekend. I'm also going to start to replace all the vacuum hoses and replace the wiring loom.

I can’t tell the rev change by the tachometer, but you can feel it at idle with your foot on the brake, there is a slight surging of the car. If I had to guess 100 RPM.

[Georgeandkira]

1) Yes, the spark plugs are under that plastic cover. Compressed air is helpful to clean dirt from each well. Remove / install plugs on a cold engine.

2) The turbo-compressed air is hotter and is routed through a radiator (called an intercooler) to cool it. This aids in preventing pre-detonation.

Which "wiring loom" are you planning to replace and why?