HUNTING!!

[TVRIK]

Hi fellow Wedgers.

Can't seem to see why she is Hunting??

Seems fine on the motorway, accelerates fine, well as fine as I know, never driven another wedge.
But on tick over its Hunting! And when driving on low revs slowly it's lurching a bit?
Any ideas, something simple I could check first??

Rik

[Number 7]

What is the tickover speed? I set mine (on the 400 and the 350) to 1K, which helps keep the oil pressure up a bitt and the coolant circulating better. Also helps when the fans etc kick in as there is no idle control with the flapper.

[mrzigazaga]

Check all the hoses around the plenum..EAV and the vacuum hoses from the FPR to plenum and the distributor vacuum.
What is you idle..Have you adjusted anything prior to it happening?...Ziga

[DEKE]

Had the same issue with my 350i on start up and tick over, following advice on here turned up the idle screw on throttle linkage and that has solved the problem, was ticking over around 400 - 500 set now around 900 and a thousand.

[Rockettvr]

Air leaks after the AFM is the usual cause of hunting -although when I had problems with mine it was the little rubber bung on the idle adjustment screw was too short allowing the screw to vibrate loose dropping the idle down too low- as said try setting to around 1k rpm. Also mine is much smoother idling on decent 99 RON fuel.

[TVRIK]

Nice one guys.. I've adjusted the throttle to just over 1000rpm
But it's still the same, doesn't stall but, still hunts
I think it could be a leak someware, but can't see where,
Should you be able to hea air?? I can defiantly hear something,
The screw directly on top if the plenum, should that be screwed tight clockwise? Not that it is, just wondered?
It's just if I turn it clockwise the sound if the air reduces. But the tick over also reduces.

Rik

[mrzigazaga]

Hi mate..980-1000rpm is good..Its best to physically check the hoses around the plenum..
Check all the ones that are blue and orange in this pic of mine.
The screw you are talking about is the idle screw and it controls the air being allowed into the plenum..It shouldn't be closed off completely and I'm not sure the engine would run if it was...Check the hoses first...Give them a little twist to see if they move..Tighten up the clip if they do...Ziga

[smash]

Take the big breather pipe off from the plenum end (the one that's connected to the flame trap on the drivers side rocker cover). Blow into the pipe and it should pressurise - you shouldn't be able to keep blowing air into it. If you can there's a leak which will allow the engine to pull air without it going through the AFM.

I had a big problem with this as you could easily blow through the pipe due to the rocker gasket completely failing to seal on the rocker in one section. Sorter the rocker gasket and it sorted the idle. If this is the problem with yours thank Adam Quantrell for this tip!

[TVRIK]

Thanks again guys, I have to say the main hose is a bit makeshift, but does still look sealed and tight!
Will defo try blowing that hose... Ahem!
I have had the rockers off to paint, could be it's not seated right,

Will give all these things a go tomorrow dudes

Really thanks again as always so helpful on this forum!

Rik

[Wedg1e]

1000rpm is way too high for normal idle, it should be 850+/-50rpm unless you have a cam with profiles like the Andes.

[TVRIK]

smash said:

Take the big breather pipe off from the plenum end (the one that's connected to the flame trap on the drivers side rocker cover). Blow into the pipe and it should pressurise - you shouldn't be able to keep blowing air into it. If you can there's a leak which will allow the engine to pull air without it going through the AFM.

I had a big problem with this as you could easily blow through the pipe due to the rocker gasket completely failing to seal on the rocker in one section. Sorter the rocker gasket and it sorted the idle. If this is the problem with yours thank Adam Quantrell for this tip!

Hi mate

Yeah I can easily blow into that pipe, did it about 7 times, no resistance at all,
So maybe take my rocker off and check it's sealing right, is that right?

Rik

[MrPicky]

There are meant to be four holes into the crankcase.

1) Oil filler - make sure the cap/orange think is on properly.
2) the flame trap, this is where you are blowing into.
3) the breather - on the opposite rocker from the flame trap, this should have a small hole and an oil trap/gauze over it, it should not pass too much air at breath pressure.
4) the dipstick - make sure that this is fully in the hole.

Any other holes should be noticeable by fairly big oil leaks, they could be in the rocker gaskets (especially if you have just had one off), the valley gasket, the sump oil seal, the front crank seal or the rear crank seal - not much else to leak.

You need an assistant to help you test who can feel the draught on the back of their hand.

Last thing is to wipe your lips after blowing because you will have a black circle around them ;-))

Russ

[smash]

TVRIK said:

Hi mate

Yeah I can easily blow into that pipe, did it about 7 times, no resistance at all,
So maybe take my rocker off and check it's sealing right, is that right?

Rik

Yep - sounds like you've found it. Rocker cover off and check seating - use rubber gaskets next time as they seat easier than cork and have a greater margin for error.

Also check the flame trap is screwed on tight to the rocker cover.

If you've got power steering you may struggle at 850 rpm idle.

Edited by smash on Monday 26th May 10:14

[TVRIK]

Nice one Russ, think I may have found it,..........ok this is a little embarrassing!




I've managed to get it back but still hunting, bit as bad, and it's running better.

But it's no surprise it still hunting?' The gasket is fooooked!!

[TVRIK]

smash said:

Yep - sounds like you've found it. Rocker cover off and check seating - use rubber gaskets next time as they seat easier than cork and have a greater margin for error.

Also check the flame trap is screwed on tight to the rocker cover.

If you've got power steering you may struggle at 850 rpm idle.

Edited by smash on Monday 26th May 10:14

Got to be it Smash!! See pic!!!

[smash]

So that's 2 of us who owe Adam a drink at BBWF!

Just to make sure - stick the cover back on, disconnect the hose at plenum and plug the hole in the plenum then see how it idles

[adam quantrill]

At this rate I'll be the one who's "smash"ed ;^)

I can recommend those rubber rocker cover gaskets - quite cheap from 4x4 people. They last a lot longer and are reusable.

[mrzigazaga]

Agree about the rubber gaskets but make sure they are like this with the ribbed surface and eyelets...

[TVRIK]

Sherbert!! I miss read... I've ordered the cork type!

Is it a big difference?

Rik

[adam quantrill]

The cork types do work, when new, it's just that the rubber ones are loads better.