shudder when idle

[tolly]

had a prob yesterday with my AUII ute(auto trans). I noticed that when i idle the car shudders for about a second then stopped. this would happen anytime i stopped at a set of lights of whatever, also whenever i went to put the car in park from any other gear it would do it again.
Now in park or drive it usually revs at just under 1k but as soon as i pull up to stop it drops down to nearly 0, shudders then jumps back up to 1k
Anyway so i got home and i thought it might be a fuel issue, not electronic so i changed the fuel filter as i dont think it has been changed in a long while, took the car for a drive and then it was fine.
After about 10 mins i put the air con when i was at a set of lights just to demist the front windscreen a bit and then it started to shudder again. It's really strange, if the fan is on 4 (full) it's fine but as soon as i hit the A/C button i get the shuddering again.

Anyway i know it's hard to diagnose over the net, but any help would be greatly appreciated

thanks fellas! :

[JC]

Sounds like the ISC valve is not doing it's job. Look up one of GK's build threads in the workshop section; I'm sure he has a detailed procedure for cleaning the ISC. If cleaning it doesn't work, it may need replacing.

[tolly]

is that the valve that is meant to rev the engine a little more to compensate for the power you lose when you run the again

Originally Posted by JC

Sounds like the ISC valve is not doing it's job. Look up one of GK's build threads in the workshop section; I'm sure he has a detailed procedure for cleaning the ISC. If cleaning it doesn't work, it may need replacing.

[Bundy]

Mine used to to something similar about after 20min run and pulling up at a set of lights
The guys here directed me to use throttle body cleaner and remove the throttle body to clean (full of black soot) and also the TPI? sensor in the black air tube after the maf.
That sorted the problem for me.

[JC]

Originally Posted by bundy

Mine used to to something similar about after 20min run and pulling up at a set of lights
The guys here directed me to use throttle body cleaner and remove the throttle body to clean (full of black soot) and also the TPI? sensor in the black air tube after the maf.
That sorted the problem for me.

That works on an 8, but the 6's don't have a MAF. The ISC is the usual culprit, as well a sticky TB.

Originally Posted by tolly

is that the valve that is meant to rev the engine a little more to compensate for the power you lose when you run the again

Yep - that's what it does. To check if it's buggered, put a .75 feeler gauge in between the accelerator linkage on the TB and the stop screw on the TB, and disconnect the ISC. The engine should idle fine. Then reconnect the ISC - if the engine runs fine with it disconnected, but stalls or revs too high when you reconnect it, it either needs cleaning or replacing.

[GK]

You called? LOL!

Cleaning ISC Valve
http://www.fordforums.com.au/showpos...9&postcount=43

Hope it helps.

Cheers,

GK

[tolly]

thanks guys i actually did a search and it sounds like a few of the guys on the forum have had a similar problems and they suggested clean the IRC and throttle body.
Found a guide to do each of these with photos (thanks GK).
That's what i love about this forum. Chances are if you want something done to your car, someone has done it and if your lucky in somecases they have posted a guide. Thanks to everyone who takes the time to take the photos and do the writeups for these. You're all champs.
Anyway, enough with the lovin lol :
i'll pickup some carby cleaner from supercheap tomorrow and give it a go.
I'll let you know how i go with both. Sounds to me like it should be done anyway every now and then.

[nob92@]

just a thought, i had this prob a few times and it was after i had disconected the batt, casue the ecu was reset and not learnt on how the car should operate efectivley. did u disconect the batt at all lately

[tolly]

yes i did disconnect the batt on wed night actually, that's just when i started getting the problem.
Just realized about half an hour ago my car is leaking fuel. it's coming from the fuel filter that i replaced on thursday, jumped under the car and tightened this up super tight. Although i always thought this should never be super tight, even though it was an absolute mission to try and untighten to change it, ah well might've been coz it looked kinda old.
Got some carby cleaner from super cheap also so i'll clean out the irc and the throttle body now and i'll let you know if that helps. Hey do i needa replace the gasket on the IRC? mine just fell to pieces when i touched it. I got some .8mm oil joint gasket material but not sure if this is suitable for fuel too. Could i get some advise on this?

[GK]

It'd be fine I'd say.

GK

[realor]

not sure if this is the problem, but common problem with au's rough idling is caused by loose intake manifold bolts... I tightened mine up (well, the ones I could get to) and the problem went away

[tolly]

okay went to clean the throttle body and mine looked like this:
http://i200.photobucket.com/albums/a...y/IMG00052.jpg
how do i take it off, seems like there are screws everywhere and i dont wanna touch it just yet till i know what i'm doing

Also the only other thing i can think of doing is re-setting the ECU with the guide from AU falcon

[AUIII]

remove the two bolts with a 10mm socket then that ring is like a rubber band use a screwdriver to stretch it off

[AUIII]

It worked a treat for me today big thank you to GK my car has been shuddering when stopped at traffic lights as well.

First i cleaned the ISC valve it improved a bit but was still shuddering slightly I then cleaned the throttle body and it stopped. Great instructions GK. Thanks

[peterban]

Sounds like another vote for a GK manual.
Could be a money spinner George!!!!

[GK]

Originally Posted by AUIII

It worked a treat for me today big thank you to GK my car has been shuddering when stopped at traffic lights as well.

First i cleaned the ISC valve it improved a bit but was still shuddering slightly I then cleaned the throttle body and it stopped. Great instructions GK. Thanks

You are most welcome.

There's lots of shared knowledge here.

Cheers,

GK

[GK]

Originally Posted by peterban

Sounds like another vote for a GK manual.
Could be a money spinner George!!!!

Or could be a money spanner! LOL!

GK

[tolly]

reset the ECU last night seems to have fixed the problem slightly

just worried that when i take the ISC valve appart that the gasket will fall to pieces, when i touched part that was poking out from it, it pretty much just fell appart

[JC]

Originally Posted by tolly

reset the ECU last night seems to have fixed the problem slightly

just worried that when i take the ISC valve appart that the gasket will fall to pieces, when i touched part that was poking out from it, it pretty much just fell appart

Nothing a smear of silastic gasket wouldn't fix though (note - just a smear!!).

[HLC]

ok heres one to stump you all lol


ive done plugs, leads, cleaned throttle body and ISC, reset the ECU and lifted the base idle a touch

and it still does it when it gets to operating temperatures at lights.


the injectors are in need of a clean, but they arnt desperate. and ive got no idea how to do/where to do the fuel filter?????

any other ideas?



im thinking i should just bend the exhaust hangar so the exhaust isnt rattling on the rear bumper hahaha problem solved!

[tolly]

HLC i would try changing the fuel filter. Go to supercheap (that's where i went ) they can look up the type of filter you'll need for your car.
From memory it was around $25. It was a vavoline VF15. That suited mine fine it's a AUII XLS ute.
The fuel filter was located on the front passanger side about 2 feet back from the front wheel arch and one foot in.
Would do it for you but you're in syd