Eratic idle and can't get over 40 mph!?

UKRAMAIR

Hey,

So the car's been okay, then suddenly at the end of a 10 mile drive, my idle starts getting eratic. Then On the drive home, I couldn't get above 40 mph in any gear, foot to the floor....
I know the exhaust manifold is cracked, and I'm buying a replacement, but is that all it is? I wonder if it could be the idle control valve as well?

Now I'm home the idle has returned to stable rpm at 1000 rpm at tick over
Any other ideas?

Cheers for the advise,
Paul.

JohnnyN

There isn't an idle control valve on the z22se. Might be worth checking the plugs? Could be a faulty MAP sensor?

JohnnyN

Air leak? Fuel filter? Vacuum pipe? Cat blockage? How is the car driving at the moment?

UKRAMAIR

Just had new plugs and fuel filter, so it's not those.

Before journey car was driving okay, just a slight occasional hint at hunting/idle.
Bit juddery at times during driving. Not driven it since I couldn't get above 40mph, as I'm worried I might do some damage.

Passed MOT only a week ago with advisory about exhaust leak (manifold), could that be all it is?

JohnnyN

EGR?

UKRAMAIR

Hmm, thank for the advise, Ill look into all of the above.

Is anyone of those more likely to of caused the loss of mph than another?

si_c1978

was the eml on? if so it'll go into limp mode to in theory stop you from wrecking your engine

MikeS

sounds like limp mode

major sensor failure or mechanical failure like timing or blocked cat

UKRAMAIR

Okay thanks for all the advise.
No, the eml light is still off.

Once I replace the exhaust manifold I hope to be able to narrow down the possabilities and get a better idea :problem:

BURT150

That sound like the cats broke up and blocked either that or your pre cat if you still have one? just unbolt the down pipe and start it up to see if theres a difference. That'l rule that out anyways :thumbup:

Huskyman

I agree with Burt 150, if your engine really growls under load and it is runnning really hot the cat has probably broken up and blocked the downpipe. Had this happen to my Saxo VTS (Many years ago!!) and I had all these symptoms. Good excuse to bin the pre-cat methinks... :think:

Martyn

Could be your Coil pack? mine lost everything and was shaking when trying to go over 50, See if you can find someone else with the 2.2 and try theirs

vocky

a cracked manifold can cause the cat to melt :thumbdown:

MikeS

or even a misfire

UKRAMAIR

Hmmm, idle returned to normal, and it drove fine today, then as I pull up at home, the idle problem came back :?
It is defo a tad louder, so I'm hoping it is just the manifold

MikeS

where do u live

willing to plug in my laptop for you

UKRAMAIR

Very kind offer Mike, but I think I'm a long way off, on the Essex / Suffolk boarder near Sudbury.

The info and advise is hugely appreciated :thumbup:

MikeS

aye that is a trek

UKRAMAIR

Hmm, noticed something else today, which got me thinking (can be dangerous!).

I've done the 12p mod on the intake after blanking off the EGR, and it's not sealing properly, and makes a hissing noise.
I could just get myself a VW plug, which I hear will seal it 100%.
When I put my finger over the leak, my idle returns to normal (back to 1k rpm, instead of 2k rpm).
We all do air intake mods to reduce the restrictsions into the engine.
With my intake not sealing properly, it is obviously getting more air than it would sealed (hence why my idle returns to normal when blocked with a finger).

Now, I know my exhaust manifold is cracked, which isn't helping matters, and I'm buying a replacement, which I hope is the cause of my erratic idle and lack of getting over 40mph.
On Sunday my car drove fine untill I got home notsure.gif ....

So, should I get this vw plug, or should I allow my engine to have the higher revs it gets with the leak, as surely this should be better for performance???
I know my engine proberly runs a tad lean with the leak and has a high idle, but is it good for performance (assuming the other problems are related to the exhaust manifold).

Opinions wanted

si_c1978

you can use gasket paper infront of just the 10p and that sealed mine nicely.