Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: minifreek on 10 August 2014, 17:42:27
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Anyone shed any light on this slight problem..?
Iv got all the stuff for the conversion from short nose V6 plenums to the more torquier long nose plenums, I fitted all the gubbins etc but had a weird problem of a vacuum leak and the tickover was at 3K.... so I unplugged the ICV and the tickover dropped to around 500 rpm.... about normal....
So set about giving it a drive and the gearbox won't change up from 1st to 2nd unless the revs was at 6K....!!!!
OK, so changed back from long nose plenum to short nose and everything went back to normal...?
Im presuming the vacuum leak was to blame for the fast tickover problem, but why wouldn't it change gear...?
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Maybe vacuum leak was the wrong word...? maybe it should have read air leak....?
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Silly answer I know, but is the Penlium sitting correctly on the Inlet divider?.
Any Air hissing noises with a quick fast rev, try some Brake, Carb, Switch Cleaner around all the hoses, inlets etc and check all the hoses around Throttle Body etc.
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Are the injection manifolds the same throughout the V6 range.... do you know...?
On mine I have Vectra Challenge heads from engine #020, with 4 G cams fitted, 3.0 lower divider and 3.0 bottom pulley - standard injectors...
I have everything off the top of a 3.0 engine - i.e long nose plenum, injection manifold and injectors and lower divider... should I use the injection manifold off the 3.0 V6 instead of the 2.5 V6....?
Any help gratefully received.. :)
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Certainly later v6 inlet manifolds are the same... can't see earlier ones being any different :-\
Incidentally, have you tried swapping out or cleaning the ICV? Assuming you have a 2.5 one and a 3.0 one :-\
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Yes that was the 1st thing I did.. I swapped the ICV's and still the same. I even disconnected the throttle cable but still revving at 3K... I don't suppose the TB's are different sizes are they...? maybe the 3.0 TB has a bigger flow than the 2.5... I can't see them being different myself but maybe someone with a better idea can shed light on this..?
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If you have both in front of you, then you're best placed to compare them :y
Did you change the throttle cable for the longer one?
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There was no need to replace the throttle cable as the 2.5 cable fits without stretching, same as the cruise cable too...
I'll have a play tomorrow if the weather is OK and see what I can do with them...
All I'm trying to do is get some bottom end torque back after fitting the G cams, theyre fantastic once they start to produce the power but they seem to lack bottom end torque and Iv been told this is the conversion to do by others that have done the same thing to their Omega's when they had one...
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Did you swap the throttle pot from the original setup over.
Thee are two variants with different pin outs, mixing them up makes the ECU think that the throttle is at WOT when its not and you get some really weird effects
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No I didn't swap them over, I shall give that a try and see what happens :)
Thanks for the replies folks, much appreciated...
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S U C C E S S !!!!!
Swapped over the TB for the 2.5's and everything is working as it should now :)
Took it for a quick drive around and it pulls and pulls like a train, I only need the 3.0 ECU as apparently it has a better map then the 2.5's so I'll be on the lookout for 1 of them in good time :)
Only thing I did find that was wrong, was there was a vacuum leak from the plastic thingymajigger on the top of the plenum with the ECOTEC printed on it, swapped that over for the 2.5 thingymajigger and thats cured the vacuum leak :)
Thanks for the help and suggestions, Im happy with the way me Miggy runs and drives for now :)