Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: anddyy88 on 19 February 2014, 15:44:56
-
what would cause the revs to stick usually around 1800-2000rpm.
very anoying as its doing it between gear changes and when your pulling up at lights.
ive had a quick look for air leaks, when i done the cam cover gaskets the other day but couldnt see anything obvious.
if i unplug the maf it will stick for about 1 second then return to normal idle (if 500 rpm is normal idle speed) rather than the 10 or so seconds that it does with it plugged in.
had a play with the diagnostics looking at the live data (not really sure what im looking for lol)
short term fuel trims are around 15% when the revs stick around 1800rpm, drops down to 0% when at normal idle
long term fuel trims are 1%.
maf readings are 10kg/h at idle and around 20kg/h at 1800rpm when the revs stick, do these seem ok?
going off these reading would i be right in presuming that its more likely to me a air leak than the maf.
is there anywhere common on the 2.6's for airleaks?
-
With engine running spray around lightly, and methodically, with carb cleaner... when the engine note suddenly changes you've just found the air leak as the carb cleaner is sucked in and goes as unmetered fuel.... once found a good wipe down with paper towel and you have a diagnosed problem and a nice clean engine .. :)
-
I have seen a failing MAF sensor cause exactly this problem on a 2.6 before. 10kg/h is a little on the low side. I'd expect 13-14.
2.6s seem to be very sensitive to a failing MAF.
-
seen as carb cleaner is cheap, will try that first.
the maf was actually fluctuating between 9-11kg/h at idle.
is 500rpm idle normal, seem low compared to most cars
-
500 rpm is about right for the 2.6/3.2 :y
-
I have same problem, except it gets worse when I disconnect the ma f.
Expect to get fuel trim dtc after a few miles/warm ups.
I was looking at vacuum but couldn't find anything.
Be interested if u find the problem as for now I'm choosing to live with it.
Good luck
-
mines a bit better without thre maf but then the engines down on power without.
not had any fuel trim dtc's, for some reason my car doesnt like me clearing dtc'c (got one for eml light out), as soon as a clearn dtcs, the engine misfires on multiple cylinders until its warmed up and then its all fine.
tried the carb cleaner trick, to look for a vacuum leak and cant find anthing with it.
thinking about disconnecting a few vaccum pipes and blocking them to see if it makes a difference.
need to get to the bottom of this as its getting on me tits :o
-
not had any fuel trim dtc's, for some reason my car doesnt like me clearing dtc'c (got one for eml light out), as soon as a clearn dtcs, the engine misfires on multiple cylinders until its warmed up and then its all fine.
A clear sign that either the MAF is failing or there's a massive air leak. Clearing the codes also resets the fuel trims, so the misbehaviour indicates, to me, that it had built up quite a bit of fuel trim in order to run properly.
-
As Kevin Wood says, something sounds like its upsetting the natural mixture. MAF does sound suspicious if its a 2.6/3.2 as readings are low (2.5/3.0 MAFs tend to just fail, not read low like DBW ones). After its warmed up, are the LTFTs drifting from 0% (on petrol, these LT trims should never deviate from 0% - LPG, due to the nature of how they are implemented in aftermarket systems, will deviate)
-
ive just had all the vacuum pipes off today, non split or loose, ive had my handheld vauum pump on the small vacuum pipes and they held vacuum for a good 10 mins, so i can rule out the vac pipes.
time too look out for a maf sensor then.
why do the revs only stick when the engine has warmed up, its fine when cold
-
update
was a faulty maf sensor
managed to use the maf sensor i had from my old vectra dti, same maf sensor just different housing :y
idle is a bit smoother, fuel trims all normal now and no sticking revs, so nice to be able to drive smoothly now