Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: markfree on 26 July 2010, 21:27:26

Title: Poor performace/stuttering engine under load
Post by: markfree on 26 July 2010, 21:27:26
As above.

This is mostly evident when towing the van - it really struggles up hills.

Solo much better but still stutters a little when you put the pedal to the medal.

Idles ok and cruises ok  - it's when you put the engine under load that it stutters.

Changed the fuel filter & air filter - slight improvement but stutter on load still there.

Bit of background :-
dis pack changed approx 2.5 years ago (done 23k)
no codes on paperclip test
spark plugs changed approx 18 months ago (done 15k)
cam cover gaskets not leaking
cam belt changed Jan 2010 (by elite pete)

So I need to diagnose where the problem lies I'm thinking dis pack/plug leads - anybody any thoughts/experience of the problem and solutions :y
Title: Re: Poor performace/stuttering engine under load
Post by: TheBoy on 26 July 2010, 21:32:48
Assuming no stored codes, I would look at HT, unmetered air or a MAf FAULT
Title: Re: Poor performace/stuttering engine under load
Post by: Welung666 on 26 July 2010, 21:39:11
I'll be up your way this time next week on vacation if you want me to run the Vaux-Com over it for you?
Title: Re: Poor performace/stuttering engine under load
Post by: markfree on 26 July 2010, 21:55:28
Quote
Assuming no stored codes, I would look at HT, unmetered air or a MAf FAULT

Thanks for replying TB

no codes (except 12 & 31 ((engine not running))
no hissing sounds so presume vac pipes ok
how do I check for MAF fault (substitution?)? :y
Title: Re: Poor performace/stuttering engine under load
Post by: markfree on 26 July 2010, 22:00:46
Quote
I'll be up your way this time next week on vacation if you want me to run the Vaux-Com over it for you?

Yes that would be great - I can either meet you at your camp-site/hotel/guest house or you can come to me.
PM me with your price dates etc. :y
Title: Re: Poor performace/stuttering engine under load
Post by: bongocraig on 26 July 2010, 23:42:43
i had a similar problem last month!, turned out to be a vac pipe incorrectly t'd off near the vac pipe from the servo, so the multi rams wasnt working properly, i found it used alot less fuel once fixed aswell! might well be worth checking the route of all the vac pipes following the diagrams on the forum, i cannot find the link now, but im sure one of the kind gents on here will supply it!
Title: Re: Poor performace/stuttering engine under load
Post by: Omegafantasy on 26 July 2010, 23:52:48
This could be an interesting read, sounds like my car..

If it suddenly became this way, there's little chance there's an error with the vac pipes.

Does this happen at any rpm or in a specific range? I'm tempted to guess at a partially blocked exhaust.
Title: Re: Poor performace/stuttering engine under load
Post by: Mr Skrunts on 27 July 2010, 01:37:53
Quote
This could be an interesting read, sounds like my car..

If it suddenly became this way, there's little chance there's an error with the vac pipes.

Does this happen at any rpm or in a specific range? I'm tempted to guess at a partially blocked exhaust.

Check the back box, when the baffles collapse the horse hair sometime starts to block the rear pipes.
Title: Re: Poor performace/stuttering engine under load
Post by: Dima on 27 July 2010, 08:11:24
I think you need to check fuel pressure under load to ensure that fuel pump is ok. Also check plug leads: in the night open the bonnet, turn the light off and look carefully at the leads on idle and high rpm, if plug lead ok you will not see blue sparks around them.
Title: Re: Poor performace/stuttering engine under load
Post by: markfree on 27 July 2010, 22:21:43
Thanks for all the helpful replies.
Found the problem - just this minute ran the engine  (in the fading light) and lo and behold there were flashing blue lights comming from the n/s bank so I guess my plug leads need changing - thanks to dima for his excellent suggestion :y
Title: Re: Poor performace/stuttering engine under load
Post by: Dima on 28 July 2010, 07:46:45
Quote
Thanks for all the helpful replies.
Found the problem - just this minute ran the engine  (in the fading light) and lo and behold there were flashing blue lights comming from the n/s bank so I guess my plug leads need changing - thanks to dima for his excellent suggestion :y
great  :)
please let us know if changing plug leads solved performance problem
Title: Re: Poor performace/stuttering engine under load
Post by: pewseyomega on 25 August 2010, 19:31:03
Just finished changing leads and that seams to have solved the problem.
In the end I found the problem on no 6 cylinder, the insulation around the plug had split (clumsy mechanic when changing plugs on service?) and was arcing to head.
Now runs like dream, but have yet to get her hot and on a motorway.
A few tips for changing leads yourself. If you buy aftermarket leads they don't come with shielding, so cut mine off originals and resecured with straps. try and be left handed. Do buy plasters. Remove wiper motor, comes out quite easily and provides plenty of room - but mind the breather on top of heater valve, probably expensive and difficult to replace if damaged. If you find yourself with a breater pipe over - don't worry it is a gearbox breather and doesn't attach anywhere (thanks to the guys who answered my cry for help inside 5 minutes!).
Andy