Poor running at high revs

[AdamjVR6 0]

Hi there,basically my VR6 just flew through an MOT after after being garaged for 4 years! yipee.

However,as i havent driven it much i have been keeping the battery disconected to stop it going flat.

The lad who sold me the car said that when he fit a green cotton filter to it he rememberit ran like poo for a while then gradually got better as the ECU learns??

 

would disconecting the battery be the reason why my C is running crap,by crap i mean the following:

 

Idle hunts between 1200 and 200 rpm (and frequently stalls!)

Car picks up speed fine up to around 4500RPM then it stutters a bit and holds back then after about 6000RPM just starts to fly then you have to change gear for the afore mentioned to happen again!!

 

Is it an idea to just by a standard air box from a member on here as i dont care about induction noise,the engine purrs good enough.

 

FWIW it just had a new coil pack and various things to do with idle,plastic things with foam inside them and stuff :lol:

 

Any help much appreciated as im new to VW and a little disheartened already as i though they were very reliable :(

 

thanks in advance

[KADVR6 0]

first thing i would do is either put some redex in the fuel tank, or if the fuel level is lowish?? fill it up with the finest petrol that is near you. if the car has been standing for 4 years with the same petrol in it?? it will run like a real pile of poooo.

 

i had a green cotton air filter on mine years ago, and it ran 100% fine.

 

karl

[herisites 0]

I was going to say petrol as well. Disconnecting the battery will reset the ECU so it will be learning again which is why it hunted for idle when first started, there is an ECU reset procedure in the Knowledge Base which is the best way of getting the ECU to 're-learn'. After a while though the ecu will have learnt what it needs and it should drive as normal.

[AdamjVR6 0]

right,yeah well the car had a full service and the tank was drained and fuel filter changed.

 

I dont really trust red ex and other so called additives,ive been told from some people clued up peeps in the past the can do as much bad as good.

 

Maybe i should try putting in some super unleaded as i have no idea what the ignition advance is on the car or is it not adjustable on corrado's?

[dukest 0]

if its a VR it should really be getting super anyway.. AIRC they are recommended for 98RON fuel.

not that you should be getting your issues just from "normal" fuel though..

[dr_mat 0]

Just resetting the ECU wouldn't cause running that poorly, sounds more like you have an actual problem. Easy way to find out is to scan the ECU for error codes ..

[AdamjVR6 0]

Yeah,i'll get it up to my local auto electrical place this weekend and see whats what.

I still think im going to get a stock air box back on there,VW did spend millions designing this engine to work perfectly with it after all :lol:

 

Hopefully its nothing to serious,i doubt it since its an intermittant problem.

 

I.E. not always at the exact same revs and not doing it everytime i drive the car.

seems more prone to happening in later gears like third and fourth.

Thanks for the help so far fellas,appreciated 8)

[dr_mat 0]

im new to VW and a little disheartened already as i though they were very reliable :(

 

Be fair: you used to own a Honda...!

[Kevin Bacon 5]

If it's holding back at 4500rpm, that sounds very much like a dead Cam sensor to me.

[AdamjVR6 0]

If it's holding back at 4500rpm, that sounds very much like a dead Cam sensor to me.

 

not precisely there,i used that purely as an example.

 

I'll give it a week before i sell it and buy another honda :lol:

[Kevin Bacon 5]

Well that's when the engine goes open loop lambda and is 'on the cam' and if the cam sensor is out, it will retard the ignition.... to the point of losing you 30hp.

 

If you want to keep the car, a laptop and VAG-COM diagnostics software is a wise investment 8)

 

If you do get another Honda, make sure it's an import Integra or NSX.... the only Rhondas worth owning imo :lol:

[dr_mat 0]

Don't think the cam sensor would explain the dodgy idle though. But hey, so far we're all just speculating till you get it VAGCOMed ...

[AdamjVR6 0]

If you do get another Honda, make sure it's an import Integra or NSX.... the only Rhondas worth owning imo :lol:

 

haha,cant insure an nsx just yet,nah,anything with a B series engine is gonna be fun!

 

Right,well first thing im gonna do is get a tank of fuel in there,i only just twigged that it appears my VR6 doesnt actually have a low fuel light.

 

I put 1 gallon from a gerry can into it after they completely emptyed the tank.Then drove it 15 miles home so i guess its nigh on empty again seeing that it tells me im averaging around 18 MPG :lol:

[dr_mat 0]

I put 1 gallon from a gerry can into it after they completely emptyed the tank.Then drove it 15 miles home so i guess its nigh on empty again seeing that it tells me im averaging around 18 MPG :lol:

 

Um, yeah, that might do it .. !?!

[Kevin Bacon 5]

Don't think the cam sensor would explain the dodgy idle though. But hey, so far we're all just speculating till you get it VAGCOMed ...

 

Well without a cam sensor the ECU can't do sequential injection, so the combination of retarded ignition and richer batch injection can cause idling probs...... but if it's hunting up and down wildy, there's either an air leak or the ISV is sticking.

[AdamjVR6 0]

hmm,got a full tank in there now and all seems well,still idles a tad low but no stalling lately so i guess i'll just give it some time to see what happens.

 

Have to be honest though,although its quick i expected a 2.9 to be a lot faster!

I guess its because its so heavy to be fair,specs show these car have lots of torque not so much bhp,so may get a caravan :lol:

[dr_mat 0]

Have to be honest though,although its quick i expected a 2.9 to be a lot faster!

I guess its because its so heavy to be fair,specs show these car have lots of torque not so much bhp,so may get a caravan :lol:

 

~ 180lbft, 190bhp, so more power than torque in pure numerical terms. But once again - it's no buzzing Honda CRX engine, it has a much more lazy approach to producing it's power.

Keep it between 3800 rpm and 6000 rpm to get the most out of the VR, plus, if you DO have a faulty sensor on the engine, chances are it's not putting in the right numbers anyway.

[AdamjVR6 0]

yeah,i see it needs to stay well above 4K to keep its pep going,dont get me wrong,it seems like a good car,with great performance,but just not the rocket i expected for some reason,im sure its the weight,lighter cars always seem faster at least.

 

Also i detest the gear stick design,its like waving a stick in badger hole :lol:

Anyway,better stop slating the old girl before i get banned

[Jim 2]

Wouldn't be no banning! We're not that nazi around here. Be under no illusion, whilst I love my car I could reel off a list of 20 or 30 things about it that pi$$ me off from a design point of view!

[AdamjVR6 0]

Wouldn't be no banning! We're not that nazi around here. Be under no illusion, whilst I love my car I could reel off a list of 20 or 30 things about it that pi$$ me off from a design point of view!

 

Hahaha,thats good to know then,pn the whole it seems like a good car,i like the dimmable speedo cluster,thats a nice touch,door handles are a little cack but then it is an old car i guess,gotta love the spoiler though :wink:

[dr_mat 0]

yeah,i see it needs to stay well above 4K to keep its pep going,dont get me wrong,it seems like a good car,with great performance,but just not the rocket i expected for some reason,im sure its the weight,lighter cars always seem faster at least.

Also i detest the gear stick design,its like waving a stick in badger hole :lol:

 

How heavy was the CRX? The web suggests it's about 1000 kilos.. so yeah, the VR is about 200kg heavier, and not that much more powerful if you had 170bhp to play with before. Power/weight is probably lower on the VR as it happens.. You'd need 205 bhp in the VR to retain the same power/weight ratio.

 

The gear change on the VR is lovely though .. bit of a long throw, but fluid as you like (at least when they're relatively new). But again, that's another common difference between german and japanese cars - the gearchange is always tighter and more positive.

 

The big difference with the VR is going to be torque.. your CRX produced only 112 lbft at a scary 7100 rpm .. The VR will be positively lethargic by comparison - peak torque is 180 lbft at only 4800 rpm ..

 

Chalk and cheese, really..!

 

Don't talk about the door handles. The moment you talk about them they break ...

[AdamjVR6 0]

To be fair i did have a B&M short shifter and stabalizer kit on the rex,so it was seriously close gear changes but i liked it that way.

 

Yeah the power to weight ratio's are very similar but the VR has about an extra 60 ft/lb's of torque so should be faster i thought,but as mentioned,a totally different power delivery all together,vtec engines are high revving beasties whereas these cars seem a to have a good pwer range.

 

You could probably lose a lot of the weight on a corrado though with CF panels but then you have to weigh up safety with performance and whether to just buy a lotus elise instead :lol:

 

EDIT,My crx made 120 ft/lb's at 8200 :wink:

 

~Here was the old girl

 

crx power run

[dr_mat 0]

Yeah the power to weight ratio's are very similar but the VR has about an extra 60 ft/lb's of torque so should be faster i thought,but as mentioned,a totally different power delivery all together,vtec engines are high revving beasties whereas these cars seem a to have a good pwer range.

 

You could probably lose a lot of the weight on a corrado though with CF panels but then you have to weigh up safety with performance and whether to just buy a lotus elise instead :lol:

 

EDIT,My crx made 120 ft/lb's at 8200 :wink:

That's a bloody motorbike engine! lol

 

The extra torque helps of course, but "fast" means different things to different people. The "fastest" cars in terms of outright performance are always the ones with the highest power(bhp)/weight ratio. Think about it: your modern turbo diesel produces ~300 lbft at 2500rpm. Pretty earth shattering torque, but outright 0-60 times no better than a 2.0 16v petrol engined car. Then consider a formula 1 car - about 250lbft of torque, so not even as much torque as the diesel, but ~900 bhp means 0-60 in about 2 seconds ..

 

But for day-to-day driving the VR (or the diesel) is more likely to give you the performance when you want it than the small revvy thing that needs 6000 rpm wound onto it before it wakes up..

 

Horses for courses: the VTEC engines are masterpieces of technology, but when you're not in the mood for revving it there's no replacement for displacement.. ;)

[AdamjVR6 0]

you just hit the nail on the head!

 

As a point of interest and to go back to the original point of this thread the car has been fine since filling up the tank with a whopping £75 :shock: