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Omega Help Area => Omega General Help => Topic started by: blootak on 29 June 2008, 17:43:51

Title: trouble after rebuild
Post by: blootak on 29 June 2008, 17:43:51
Hello peeps

my 2.0l 16v slowmega popped its head gasket at cylinder No 4

so i decided to do a rebuild having never done one before ( and thats why it took me 6 months) anyways

I'm having trouble with it running properly

The car will fire but idle's really high @ 2000 rpm, disconnect the idle control valve and the revs drop to 800 rpm

I've changed the ECM temp sesnor, crank and cam sensors
but i'm getting a "Hall sender signal fault" constantly which we believe is why its reving high

is there something i've overlooked ?



Title: Re: trouble after rebuild
Post by: rickyboy on 30 June 2008, 00:43:20
Can you do the paperclip test and read off the fault code chart in the guide just to confirm your code is the crank sensor (hall effect sensor).  If it flashes 10 times count the number as a zero.  Link below...  

I doubt that's the reason it's idling high - more likely that the idle control valve needs cleaned.  

http://www.omegaowners.com/forum/YaBB.pl?num=1189022687


Title: Re: trouble after rebuild
Post by: blootak on 30 June 2008, 07:07:02
cool i'll try the papr clip test

but mate told me to clean that valve, it seems very free, could the solenoid for be sticking ? because when i disconnected it the rev went back to normal ?
Title: Re: trouble after rebuild
Post by: magnul on 30 June 2008, 07:14:38
If it revs high I'd suggest you look for vacuum leaks.
Title: Re: trouble after rebuild
Post by: haj on 30 June 2008, 15:47:27
Had this problem after cleaning breathers,throttle.Turned out i was a bitheavy handed with the outer accelarater sheath,not enough slack to adjust the butterfly valve,slackened it off ,adjusted butterfly valve to closed,almost,no probs since.

just a thought
Title: Re: trouble after rebuild
Post by: Mr Skrunts on 30 June 2008, 15:53:25
Hi blootak

If you fill in your profile you might find there is someone local to you that maybe able to give you a helping hand.  :y
Title: Re: trouble after rebuild
Post by: rickyboy on 30 June 2008, 16:48:14
Is it possible the mechanical idler on the throttle body has been tampered with at some point?  If it's an air leak I'd imagine the revs would start low then climb up.  

Mabye an idea to take the ICV off again, give it another clean then make sure you lubricate it.  See if that cures it.
Title: Re: trouble after rebuild
Post by: blootak on 30 June 2008, 20:15:59
right i've done the paper clip test and i got 92 -cam sensor fault

could my ECM be fried ?  there's no seriel label still on it

how can i tell which ECM i;ve got ?

Title: Re: trouble after rebuild
Post by: fred117 on 30 June 2008, 20:35:00
hi just rebuilt my engine yesturday and today its a 2.0
i have a problem now when the rev die down i get a poping from the exhaust  can some give me a bit of help to sort it out  
Title: Re: trouble after rebuild
Post by: rickyboy on 30 June 2008, 20:40:14
Quote
right i've done the paper clip test and i got 92 -cam sensor fault

could my ECM be fried ?  there's no seriel label still on it

how can i tell which ECM i;ve got ?


Very unlikely the ECM is fried.  Easy fix for this code.  You can either clean it and see if it disappears (usually does) or replace it and it will go.  Take off the spark plug cover (ecotec strip).  Take off the timing belt cover and the sensor sits in between the two cams.  Remove the plug at the top of the sensor then remove the sensor itself - clean the sensor and it's mating surfaces then re-fit.  I

f the code doesn't go then replace the sensor.  Use genuine vaux parts.
Title: Re: trouble after rebuild
Post by: rickyboy on 30 June 2008, 20:41:45
Quote
hi just rebuilt my engine yesturday and today its a 2.0
i have a problem now when the rev die down i get a poping from the exhaust  can some give me a bit of help to sort it out  

Most likely the idle control valve needs a clean.  Post a new topic for this...
Title: Re: trouble after rebuild
Post by: blootak on 30 June 2008, 21:09:22
cheers rickyboy

i;ve had a new sensor on it and its still finding the code

i tried wiping the code out but it doesn't seem to want to go

Could it be the reader i;m using ? and can you use the paper clip to reset the codes ?

Title: Re: trouble after rebuild
Post by: philhoward on 30 June 2008, 21:16:45
Quote
Had this problem after cleaning breathers,throttle.Turned out i was a bitheavy handed with the outer accelarater sheath,not enough slack to adjust the butterfly valve,slackened it off ,adjusted butterfly valve to closed,almost,no probs since.

just a thought
Mine did the same - changed the old engine (blocked breathers and blown HG), but swapped the throttle bodies over as it had the LPG mixer installed.  On startup, got about 1500rpm idle, which dropped to 800rpm on disconnecting the ISCV.  Turned out the throttle stop has been wound in (screwdriver slot with lock nut) to try and raise the idle to stop it stalling (didn't..).
Wound the stop out till it was clear, then back in till it just applied a little pressure to the throttle linkage and locked it back up.  Cured it...

Unless the EML light is on, you could be seeing an old code - which will take about 25 starts to clear..
Title: Re: trouble after rebuild
Post by: philhoward on 30 June 2008, 21:19:48
Quote
cheers rickyboy

i;ve had a new sensor on it and its still finding the code

i tried wiping the code out but it doesn't seem to want to go

Could it be the reader i;m using ? and can you use the paper clip to reset the codes ?


Was it a gen Vauxhall sensor, or a generic replacement?  I've heard that some aftermarket ones don't quite do the job..
Title: Re: trouble after rebuild
Post by: blootak on 30 June 2008, 21:30:21
notsure as my the cars at me mates garage and he did the swap, i'll check with him tomorrow

it just seems strange that the fault is there even before starting the car

once its fire it rev's to high on idle and doesn;t seem to want togo over 4000 rpm

could i have two problems here, the idle control valve sticking giving me high idle and causing the cam sensor not to reset properly because its not firing right ?
Title: Re: trouble after rebuild
Post by: rickyboy on 30 June 2008, 23:03:02
It's definitely still got symptoms of both cam sensor fault and ICV.  I'm sure all is needed to fix the cam sensor is to take it off again, clean it's mating surfaces and make sure it's sat in correctly.  No amount of clearing codes will get rid of this - the 4000rpm rev limiter is a dead give away for cam sensor.

To cure the idle try and move it mechanically - sounds like it has been messed about with.  The mechanical idler sits on the throttle body in front of the throttle cable/butterfly.  You will see a small slot with a nut behind it.  Put a screwdriver in it and turn it anti-clockwise until the idle revs lower.
Title: Re: trouble after rebuild
Post by: blootak on 01 July 2008, 06:53:16
cheers mates will have a go

Title: Re: trouble after rebuild - update!!!!!
Post by: blootak on 10 July 2008, 18:22:34
Oi oi

project slowmega is running again - WOOP WOOP just needs an MOT

it turned out i'd managed to swap the connectors for throttle position and cam sensor - what a noob

never mind, the old gal is running right

cheers for the help guys