I give up!! Au missing at idle drives ok.

[ratter]

you have dirty injectors

[ubuxkl]

Originally Posted by Uncle_Ken

Are you using a high flow air filter?
UK

No I'm not UK.

Originally Posted by INJECTED_250

manifold gaskets tend to crack and split.. this causes a leak at idle giving a rough idle... Use some CRC / water hell anything and spray it over the manifold where its bolted to the head.. if u hear a loud hissing or it runs differntly then thats ya prob.. i

Thanks Injected_250. I'll give it a try - or get my mechanic to. I'm searching for things for them to try I guess.

[ubuxkl]

Originally Posted by ratter

you have dirty injectors

They gave them a "purge" last August during a service. You think it would be that Ratter?

At the service they did in January, they hooked up the computer and it didn't return any faults.

What a pain. The damn thing drives beautifully but I hate having things like this : :

[Uncle_Ken]

Originally Posted by ubuxkl

No I'm not UK.



Thanks Injected_250. I'll give it a try - or get my mechanic to. I'm searching for things for them to try I guess.

OK thats me out. I found that a stock filter gives a better idea at times

UK

[ratter]

Originally Posted by ubuxkl

They gave them a "purge" last August during a service. You think it would be that Ratter?

At the service they did in January, they hooked up the computer and it didn't return any faults.

What a pain. The damn thing drives beautifully but I hate having things like this : :

If the car is ok on gas, the only difference is the fuel system, so the problem points to petrol, as it is only an idle problem I would say it is injectors as fuel pump or supply problems get worse as revs increase when the demand for fuel flow is greater.
Dirty or leaking injectors do not show up any codes.

[mattp]

AU's tend to get loosening of the inlet manifold bolts, which gives the same sort of symptoms as a buggered inlet gasket, so it's worth getting a size 10 spanner and giving the ones you can get to a good tightening.

[ratter]

Originally Posted by mattp

AU's tend to get loosening of the inlet manifold bolts, which gives the same sort of symptoms as a buggered inlet gasket, so it's worth getting a size 10 spanner and giving the ones you can get to a good tightening.

and that problem would show on both fuels

[TwistedEL]

Mine starting doing this when I got an aftermarket exhaust. Haven't been able to work it out yet. I've replaced the coil pack, oxy sensor, plugs and leads so I know they aren't involved.

[nitro]

Originally Posted by bellagirl67

Well got my dad to clean the throttle body but it made no difference. Then he put the idles up so it idles in park at 750-800rpm. Now in gear with my foot on the brake it idles at 650rpms. Now it doesnt stall when I come to a stop at lights etc. Hooray!! Still has a slight miss intermittently when idling in gear but I suppose I will have to live with that. At least it doesnt stall now!!

I was about to say adjust the throttle body stop screw like I did and for me it stopped the rev hang when stopping and all the hesitation disappeared just from a little turn of a screw....after all the new components I replaced ISC TPS coil packs leads plugs hahaha for me it was just a 1/4 turn of the stop screw and she idles and drives beautifully now..
Anyway going to go and check myself into a mental institution now my brain is fried.

[aussiblue]

Well got my dad to clean the throttle body but it made no difference. Then he put the idles up so it idles in park at 750-800rpm. Now in gear with my foot on the brake it idles at 650rpms. Now it doesnt stall when I come to a stop at lights etc. Hooray!! Still has a slight miss intermittently when idling in gear but I suppose I will have to live with that. At least it doesnt stall now!!

That's not really a fix it is just masking the issue and will cause increased fuel consumption and accelerated engine wear (washed bored from over-fueling at idle). It is very likely, as others have said, a vacuum leak in the inlet manifold gasket. Check for vacuum leaks particularly at the inlet manifold the bottom of number 1 and 6 where the inlet manifold mates with the head both when the engine is hot and cold. Use a length of windscreen washer sized hose with one end in the ear to listen for the telltale sucking noise of a vacuum leak while poking around under the manifold at idle. Note the pre fuel injection trick of using engine start sprays etc will often not work to find these leaks as the ECU rapidly adjust for the change in air in the mixture and it's hard to pick up any change in the engine noise or rpms. Just tightening the manifold fasteners usually won't fix it as a small piece of the gasket at the lower part of the inlet port usually burns through once the nuts have become loose.
__________________

[david lee]

my au xr6 hesitates at idle and runs perfect i squirted soapy water around the rear of engine between the gap in the inlet manifold and it instantly ran on 5 cyclinders. whats going on ?

[Blue Dog]

Looks like you've found a vacuum leak.
If you weren't looking for a vacuum leak.
Why would you be squirting soapy water on the engine?
What did you expect to happen?

[david lee]

Originally Posted by Blue Dog

Looks like you've found a vacuum leak.
If you weren't looking for a vacuum leak.
Why would you be squirting soapy water on the engine?
What did you expect to happen?

someone mentioned inlet manifold leak and said to use soapy water in a squirt bottle im hoping its an leaking injector.at least i can tell the mech what i did when he comes to pick the car up once before ive degreased the engine and hosed it off with no problems

[PG2]

Originally Posted by david lee

someone mentioned inlet manifold leak and said to use soapy water in a squirt bottle im hoping its an leaking injector.at least i can tell the mech what i did when he comes to pick the car up once before ive degreased the engine and hosed it off with no problems

Why would you be hoping it is a leaking injector when everything points to a broken inlet manifold gasket?

An inlet manifold gasket is a lot cheaper and easier to fix being a $25 job and takes about an hour to replace if you don't know what you are doing.

[david lee]

Originally Posted by PG2

Why would you be hoping it is a leaking injector when everything points to a broken inlet manifold gasket?

An inlet manifold gasket is a lot cheaper and easier to fix being a $25 job and takes about an hour to replace if you don't know what you are doing.

thanks. thats great news i thought it was the other way around i drove it today and it was good. no problem but i know it will re surface iread that the gasket is a common fault