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VX with rough idle.... possible causes?

tracey5583

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Hi Guys,

I recently bought a VX and yesterday it started idling roughly (about 700rpm) and on a number of occasions stalled on approaching a stop. Doesn't seem to have the power it had before.

What are the possible causes for this? Being a single mum I'm not in a position to take to the mechanic for something that I may be able to do myself.

Are there any basic checks I can do to try to identify the problem?

Thanks in advance :)
 

SavVYute

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The easy things to check first would be...

The 6 spark plug leads are tight at one end to the tops of the spark plugs and at the other end where they connect to the coils.

Check none of the black rubber vacuum hoses that connect to the engine and throttle body have come off.
There's one that connects to under the throttle body and a bit hard to see that can come adrift.
 

Nut Kracker

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As SavVYute said above.
It sounds like you have a vacuum leak.

The hoses pictured below are vacuum hoses that connect to the inlet manifold.
You need to inspect these hoses to see if they have a split, are perished, or have become disconnected.

The picture at top left, is the one SavVYute is talking about, as this "crankcase ventilation hose" has a tendency to disconnect its self.
The EGR pipe at top right can be a problem, but not usually.
The hoses at bottom left in the picture, are at the back of the engine.
It will be easier to inspect these with the engine cover off.

 

hotrod

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1/ purge hose under the body throttle ............ make sure its connected at both ends.

2/ if all air lines are in contact clean your body throttle and ICV or replace ICV .

3/ if its still not right replace plugs and leads .

4/ if its still not right coil pack and DFI ..... start from cheapest first good luck.

can be a blocked injector or the pressure fuel regulator .
 

chriso-k

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Hello Tracey.

Lucky for you, this mechanic comes for free.
Realistically, you need to have a scan tool hooked up to your car to see what's going on. If you do have a vacuum leak, the scan tool will pick this up immediately! Check out the pictures, by Nut Kracker, above. Especially the first one of the throttle body. There is a vacuum hose (shown in the pic) that is VERY common for "falling off". But I guess you need to know what you're listening for! Failing all this, sometimes the ECU software can become corrupted (especially if people jump start cars) and may require a simple idle reset of your software. But I would say predominantly, vacuum leaks, which is un-metered air entering the engine, need to be ruled out first and foremost Hope this helps
 

KIWI_VX_SS

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Hi guys,
Firstly, I apologise for bringing up an old post and hijacking Tracey's post, but I am having the same issue.
Anyone know if Tracey fixed her idle issue ?
My car is a VX SS auto. It seems to drive fine, no noticeable miss or hesitation under load its just @ idle it sounds like it has a high lift cam but sadly it has no hot cam yet.
I will try the things that you guys have already suggested but I don't have money to waste on the wrong part is there a way of testing the ICV, plugs n leads, coil packs etc etc ?
Thanks in advance
 

VT&VX

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I have been trying to fix this rough idle issue.
I tried to check the EGR purge hose and I think I made it come off. Now it seems too short. I bodged a bit of hose onto end and glue to get it back on, but it might be leaking NOW.
Spark plugs, leads, ignition coil, tps, IAC valve gasket and now I am waiting for another IAC valve ( VX needs the more expensive IAC552, not the cheaper IAC409).
 

Lex

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I have been trying to fix this rough idle issue.
I tried to check the EGR purge hose and I think I made it come off. Now it seems too short. I bodged a bit of hose onto end and glue to get it back on, but it might be leaking NOW.
Spark plugs, leads, ignition coil, tps, IAC valve gasket and now I am waiting for another IAC valve ( VX needs the more expensive IAC552, not the cheaper IAC409).
Have you tried a dfi with coils from the wreckers?

Those iac, they oem or aftermarket?
 

VT&VX

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They don't have a gasket. But they do have a oring. Is that what you meant?
Yes O-ring. Replaced that.
Replaced or switched out everything mentioned above. Supercheap Calibre coil pack swapped position s. (haven't done the module that sits under the coils).
IAC (might be GOSS) coming from Sparesbox, the tps from Repco was Goss. Spark plugs were an unknown brand that were supplied with the blue spark plug ignition leads. I think the brand was Eagle.
But I have swapped one of the original OEM leads through the positions and doesn't seem that is the actual problem.

Still driving the car around and the idle is still getting worse.
 
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