Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: 456lbft on 06 January 2021, 09:19:50
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Please can anyone tell me if they know why my MV6 doesn't seem to have any cold start enrichment or raised idle speed. It always starts and has a strong battery, but it just sits at about 700-800rpm from stone cold, as if it is warm, when it definitely isn't. Is here a value from the engine temp sensor that I can check? Any other ideas will be much appreciated. It won't be long before the engine comes out for a manual conversion and attention to all the oil leaks, but I'd like to sort this while it is still in one piece. Thanks
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So it starts, idles and doesn't cut out? Is that still true if you put it in drive?
Why would it need a raised cold idle if it does all that? It's working just how I would want it to.
Fast idle from a choke was always a bodge to cover the inadequacies of carbs and distributor ignitions.
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So it starts, idles and doesn't cut out? Is that still true if you put it in drive?
Why would it need a raised cold idle if it does all that? It's working just how I would want it to.
Fast idle from a choke was always a bodge to cover the inadequacies of carbs and distributor ignitions.
Thanks, maybe it is fine then, it just seemed odd to me. Most cars, even modern ones seem to have a cold start procedure which involves a slightly higher idle, even if only for a few seconds.
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Neither of ours fast idle at start up, but they are both diesel :-\
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Some modern petrol engine sound as is if they have a high or fast idle on a cold start up which subsides after a couple of minutes. This is the secondary air pump which is designed to force air into the exhaust system to reduce cold start emissions. Invariably these engines sound a fair bit noisier for a couple of minutes until the pump stops which could be mistaken for a higher cold start engine speed.
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My Vectra C 1.8 (Z18XER), runs at about 200 revs above normal when first started. If that's any help. :-\ Thank God the smileys are back to normal. ;D
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Thats normal with a 3.2
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If it helps, both my 3.2's start first turn of the key from cold, and then run at normal tick over speed whether cold, warm or hot. I imagine the engine ecu will control the mixture and engine speed relative to the signal sent from the coolant temperature sensor, which on a modern engine is a more gradual change, rather than the 'good old days?' when you used to jiggle around with the choke cable to get the best and smoithest revs relative to the amount of fuel enrichment required.
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800 is a fast idle for the 3.2.
650-700 is normal in my experience. A faulty ecu temp sender will affect fuelling.
Also, they really don't take long to heat up, so revs should back off fairly quickly unless it's properly cold.
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Thanks for all the feedback, I shall stop my paranoia and just enjoy the superior engineering of my lovely MV6s. Just need to fix the spongy brakes now... :y
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Thanks for all the feedback, I shall stop my paranoia and just enjoy the superior engineering of my lovely MV6s. Just need to fix the spongy brakes now... :y
Fix the spongee Brakes, don't rush, fit braided hoses. Every Omega I've owned has had slightly soft pedal at the start, then was sufficient.. Only omega I've driven with a hard pedal was sereks with the brake conversion kit on, and that stopped bloody quick from 70mph ;D
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Thanks for all the feedback, I shall stop my paranoia and just enjoy the superior engineering of my lovely MV6s. Just need to fix the spongy brakes now... :y
Fix the spongee Brakes, don't rush, fit braided hoses. Every Omega I've owned has had slightly soft pedal at the start, then was sufficient.. Only omega I've driven with a hard pedal was sereks with the brake conversion kit on, and that stopped bloody quick from 70mph ;D
That's the direction I am heading in, braided hoses and a very careful bleeding process including the ABS pump, followed by bigger discs and calipers similar to the upgraded ones that we fit to Lotus Carltons :y
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Not wanting to turn this onto a brake pad debate, but Omegas I have owned that have previously had a 'dead', 'spongy' or 'uninspiring' brake pedal feel, have been greatly improved by replacing the previously fitted poor quality brake discs and pads with known good quality sets which has greatly improved both 'bite' and 'feel'. I have fitted braided hoses to certain classic Triumphs which has improved the brake pedal feel and response on them, but I have had no experience of doing this on an Omega, basically as I have never felt the need to...
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exactly.
and when you think of how the calipers actually work( front: piston coming out to squeeze the combined assembly of pad,disc,other side of caliper "fingers" and rear both pistons coming out to squeeze the disc with pads and shims) ( plus the fact that you are taking up the running clearance/ relaxation first)it makes sense that any seized sliders,misalignment,bent shims,rust build up all has to be overcome before the disc actually gets squeezed its no wonder there is some initial pedal travel or softness before the brakes actually come into effect.
yes steel braided hoses will also help too but not as much as eliminating unnecessary caliper movement.
this has also become an issue if people have had a caliper with a slightly stiff sticking piston.once the caliper has been repaired/ replaced and is working correctly you can end up with 'more' pedal travel than before !
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Thanks for all the feedback, I shall stop my paranoia and just enjoy the superior engineering of my lovely MV6s. Just need to fix the spongy brakes now... :y
Fix the spongee Brakes, don't rush, fit braided hoses. Every Omega I've owned has had slightly soft pedal at the start, then was sufficient.. Only omega I've driven with a hard pedal was sereks with the brake conversion kit on, and that stopped bloody quick from 70mph ;D
That's the direction I am heading in, braided hoses and a very careful bleeding process including the ABS pump, followed by bigger discs and calipers similar to the upgraded ones that we fit to Lotus Carltons :y
There's a limit to what will fit under factory wheels.
Monaro CV8 calipers with 330mm discs is about the limit for 17"s. And this actually makes the pedal softer. The effect is instant though as it pulls the car up noticeably faster with alot less fade.
It is possible to adjust the dead spot out of the pedal, but it's fiddly to do.
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All good points and well made. In my experience, which is mainly mucking about with Lotus Carltons over the past 25 years, the more effective the calipers (and the bigger the diameter the discs are) the less you notice the softness of the pedal, because you have to use less pedal effort for a given amount of retardation. In the same way that one can bleed the brakes and get a good pedal only for it to feel spongy once the engine is running and the servo kicks in. The feel of a Lotus brakes after we've upgraded to 6piston front calipers is miles better than the already good 4 pot ones, because of the hydraulic advantage of smaller pistons and greater pad area. The only car I've had that has had a really firm pedal is my own Lotus Carlton track car, which has braided hoses throughout and (crucially in my opinion) no ABS pump. Also I am always struck by the sharpness of the brakes on more or less any new car, for instance a delivery mileage courtesy car offered by a dealer or a shiny new hire car usually takes me by surprise the first time I hit the brakes until muscle memory is recalibrated. So I am sure that the accumulated wear of every component has a cumulative effect over the years. I've also been told that the lining of rubber brake flexis can break down over time and contribute to the mushiness by trapping micro bubbles of air, so that even changing to new rubber flexis can be an improvement, never mind the teflon lined braided hoses that can be obtained. I've often wondered what method is used at the factory for bleeding brakes, because even with the fanciest pressure bleeding system, it still seems to takes ages and lots of fluid to get all the air out of a complete brake (and clutch) system.
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Actually, that's a slight mistake on my part...
Monaro 5.7 CV8 calipers are a bolt on four piston upgrade retaining the Omega v6 discs. And fit 16" wheels. No mods required.
The VXR Monaro calipers require 330x32 discs so are greater diameter AND thickness. And fit 17" wheels. Calipers bolt on but may require tweaking depending on disc choice. I used Merc ML ones machined for correct hub centre fitting and spacers on the carrier to correct for disc offset. Also Monaro hoses as longer than Omega ones. This is what I fitted to mine.
The dogs danglies are the AP set up from the Monaro, 360x36mm iirc but the discs are stupidly expensive. And you need a custom bell to allow direct fitting to the Omega hub. Calipers should bolt on but there are variations. The standard single piece Monaro discs technically fit, but are just as expensive and the bolt pcd is 120 not 110. Require minimum 18" wheels.
The difference is in a guide iirc.
Carlton options might be bolt on but you'll have to experiment. If you can get the parts.
VXR8 brakes don't fit as the caliper mount dimensions are different.
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Sounds a lot of expense and faffing about to gain what in particular? Unless you are the habit of driving like those 'ne'er do wells' on those Police Camera Action type programs, or absolutely cane the brakes with your style of driving, in my opinion, Omega brakes are more than adequate.
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Am I correct in thinking Monaro calipers use the same pads as an Omega ?
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Sounds a lot of expense and faffing about to gain what in particular? Unless you are the habit of driving like those 'ne'er do wells' on those Police Camera Action type programs, or absolutely cane the brakes with your style of driving, in my opinion, Omega brakes are more than adequate.
Exactly. Making them work as designed is hardly difficult or expensive either.
I've said this before, but if you are going to modify brakes it is only worth doing if you go straight to the biggest ones you can fit under the wheels. Changing calipers on a standard size disc is a complete waste of effort and money.
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and gm decided through great expense that the weight of the car ,etc,required the brakes it fitted.
always a personal choice but standard every time for me .same goes for silly exhausts too !
plus finding an insurance company that accepts modified cars .
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Im not sure I would agree. The Omega is a big heavy car, and Im pretty sure if it were being designed today it would have to have a much improved braking system. They were ok ish when it was made, but things move on and Omega brakes arent great by modern standards.
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Am I correct in thinking Monaro calipers use the same pads as an Omega ?
Nope :D the calipers are PBR and use a derivative of Corvette pads ;)
Sounds a lot of expense and faffing about to gain what in particular? Unless you are the habit of driving like those 'ne'er do wells' on those Police Camera Action type programs, or absolutely cane the brakes with your style of driving, in my opinion, Omega brakes are more than adequate.
Exactly. Making them work as designed is hardly difficult or expensive either.
I've said this before, but if you are going to modify brakes it is only worth doing if you go straight to the biggest ones you can fit under the wheels. Changing calipers on a standard size disc is a complete waste of effort and money.
The base Monaro calipers are a two piston caliper with a longer pad contact than the Omega ones and about a third more piston area. The VXR ones are similar to the base ones but with a greater pad area to allow for the larger discs and calipers ;)
Before uprating to the Monaro VXR set up, i used to get brake fade between Horsham and Crawley... Fast dual carriageway with five roundabouts in as many miles.
No point having a 3.0/3.2 Omega if you don't use it :D
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I believe that Pauls fitted the base Monaro calipers to his 3.2 with good results. 8)
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I've always found the standard brakes to be powerful enough and I drive a lot of new cars as well. Sure they may need more of a push ( less servo feel) but certainly pull the car up quickly if needs be.
Everyone to their own .
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I've always found the standard brakes to be powerful enough and I drive a lot of new cars as well. Sure they may need more of a push ( less servo feel) but certainly pull the car up quickly if needs be.
Everyone to their own .
After driving Fords and other over-servoed cars for many years, the progressive Omega pedal was a nice surprise. I prefer non-servo brakes, but they're only really feasible on lightweight cars ;D
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It's not that the Omega brakes are inadequate, it's just that they don't always inspire confidence and that's in part because the fundamentals of the Omega brake set up was fifteen years old when they started building them. There's a reason that Plod pads were a different spec to factory and retail ones and why they all got the bigger discs from '98 ;)
Also, fitting bigger calipers/discs does nothing to improve pedal feel, but they do inspire confidence in that they will pull the car up faster and more consistently time after time.
A well sorted Omega is a genuine pleasure to drive hard, and upgrading the brakes allows you to to make the most of it.
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Sounds a lot of expense and faffing about to gain what in particular? Unless you are the habit of driving like those 'ne'er do wells' on those Police Camera Action type programs, or absolutely cane the brakes with your style of driving, in my opinion, Omega brakes are more than adequate.
I agree for road use, but I intend to use the car on track too where the full performance can be enjoyed without risk to my license and/or other road users. As I am now closer to 60 than 50, my preference on the road these days is wafting not racing...but it's nice to have some extra reserve for when a LHD lorry wanders into my path on a motorway.
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Im not sure I would agree. The Omega is a big heavy car, and Im pretty sure if it were being designed today it would have to have a much improved braking system. They were ok ish when it was made, but things move on and Omega brakes arent great by modern standards.
Also true :y
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Back on Topic! The MV6 has started every time this last week, even when left outside on the coldest -3deg nights. I'm used to it now only ticking over at 800rpm with no drama compared with the higher cold start revs of the Lotus Carltons I am more used to, which I realise is probably due to the requirement of getting cats (which are halfway down the car) warm for emissions requirements. The swift warming of the engine and heated cloth Recaros are also most welcome on my short drive to work. ;D
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An old sage once told me, get it to stop first, then make it go round corner's, then make it go faster. 8)
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An old sage once told me, get it to stop first, then make it go round corner's, then make it go faster. 8)
And to do all of that, you start with the tyres.
I can't believe I just wrote that ::)
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An old sage once told me, get it to stop first, then make it go round corner's, then make it go faster. 8)
And to do all of that, you start with the tyres.
I can't believe I just wrote that ::)
Them too ;D