VR6 still running rough ,lumpy idle and cut out etc

[VRTrickster 0]

Right Ive sorted the starting problem which was the ISV and have fitted a brand spanker! I thought this would sort all the problems but it hasn't! :mad:

Ive still got a quite lumpy idle ,slight kangarooing at low revs and the car seems lethargic when accelerating. The car also still cuts out quite a bit!

Here's a list of what has been replaced or swapped so far :

 

New Items

 

264 Cams

Cam sender

Top timing chain

Port match inlet mani

Inlet gaskets

Injector seals

Re pro TB

TPS

ISV

BMC CDA

Lambda probe

Red Beru leads

Spark plugs

Blue temp switch

109 ECU relay

Cam position sensor

 

Parts swapped with second hand items

 

Injectors

MAF

Coil pack

ECU

 

The MPG doesn't seem to be that bad at around 30-35 steady motorway or 20-25 around town. I have started to think maybe the CPS is on its way out ,I did remove it and put it back whilst I was carrying out the work. The fuel pump relay wouldnt cause a problem like this would it ? It doesn't seem to bring anything up on VAG COM ,but I haven't tried to check it whilst driving to see if it brings up anything when it cuts out. Have any of you got any ideas as Ive run out of them and am probably going to replace every sensor etc till I cure it! I was also thinking fuel pump ?

 

HELP PLEASE !!

[steve @ 0]

Have you thought maybe about a rr session? As like you say you've replaced alot of parts and nothings showing on the vag com. That way you can see what the fueling and timing are up to. Just a suggestion.

[VRTrickster 0]

Yes I have been thinking maybe it just needs mapping or something? I was going to get it custom mapped at stealth ,but dont want to take it there if there is something at fault !

[eatthis 0]

have you cleaned the throttle body with carb cleaner??

[VRTrickster 0]

The TB is a re-profiled one which I have fitted recently.I have removed the new one and re-installed the original to see if that would solve the problem, but it never!

[eatthis 0]

ring stealth

[dr_mat 0]

Did you get the timing right .. ?

[double-6s 0]

You are chasing an invisible problem though mate.

 

Stop buying new parts and take it to stealth for them to diagnose the problem?

[Guest]

Did you get the timing right .. ?

 

That was gonna be my question.. I see you've replaced cams and top timing chain. It's vital that all the timing marks line up...

 

Like you i had a lumpy idle (before my charger) and spent loads on electrical items trying to cure it, and also doing the obvious such as cleaning the TB and ISV. It wasn't until i replaced both chains and tensioners in April that i realised what was causing it. The crank was running one tooth ahead of the cams. When we lined the cams up before removing the old chains, all the marks lined up except for the ones on the crank pulley and flywheel...

Needless to say when the new chains went on, i checked several times, and i mean several times :) , before we bolted everything back up. It idled loads smoother after that..... Until my stage 2 remap, but thats another story :x

 

Some of the others have suggested a remap, which wouldn't be a bad idea condsidering you've fitted 264 cams...

 

Cheers

Steve

[VRTrickster 0]

I have checked the cams after installation to check the marks and even took the gearbox out to have a proper look! When I fitted the cams I was concerned that I couldnt seem to get the cam marks to line up spot on but tried it tooth this way ,tooth that way so that had to be as good as it gets? After running it for a while it had lumpy idle and problems starting in damp which turned out to be the coil ,and idle was lumpy. After speaking to Vince several times for advice I decided to strip it again even further and take the box out. The lower chain I haven't moved and in standard form on the rollers the car was producing I healthy 203 bhp, so Id say it was timed correctly!

After taking the box off I could see that the flywheel/crank mark and intermediate lined up perfect. The cam marks how ever were slightly out of parallel by a mm or two! I refitted the chain over and over and still the same result! I then tried a new chain and still the same. When putting a long screw driver down number one and feeling for top dead centre and spinning the engine over till its coming up to tdc, I gently turn it to and past ,and the cams seem to line up at the point it gets to the top and starts going down. So I would say that it is timed correctly yes!

It seems fuel related, but I could be totally wrong?

Can anyone shed any more light please ?

[steve @ 0]

Have you checked the fuel pressure and the fuel pressure regulator?

[VRTrickster 0]

I havent checked the fuel pressure thats something I could check to rule out the pump. Does anyone know if the cam CPS can be faulty and cause problems with out showing up on vag com?

[CorradoVR6-Turbo 0]

Best way of finding faults is to disconnect what you think is at fault and if it shows up on vag com then you know it works.

[-Neil- 0]

Ive got the EXACT same problems as described.

I have a VR6.

I have a very lumpy idle and car stalls when coming to junctions (a halt). the revs also drop low then 'blip' back up again.

 

 

altho the wierd thing is that i resetted all the faults on the ECU, (which read Lamber oxygen sensor fault) and then it has now started to kangeroo badly at low revs in 1st n 2nd gear.

 

Has anyone any good ideas of where to start baring in mind all the parts the guy above has changed????

 

Neil

[CorradoVR6-Turbo 0]

Funny thing, is since ive removed my ISV ive never stalled or had a lumpy idle.

 

I would make sure the damper at the back of the throttle stop is working and make sure you have a slight air gap on the butterfly.

[VRTrickster 0]

On the TB position on vag com the throttle angle is at 12.1 degrees. I heard it can be anything up to 14 isnt that right ? May be I should crank her up a bit and try that ?

[dr_mat 0]

altho the wierd thing is that i resetted all the faults on the ECU, (which read Lamber oxygen sensor fault) and then it has now started to kangeroo badly at low revs in 1st n 2nd gear.

 

Sounds like you have a lambda sensor problem .. but unless you quote EXACTLY which lambda sensor error you saw, we can't be sure.

[dr_mat 0]

Best way of finding faults is to disconnect what you think is at fault and if it shows up on vag com then you know it works.

 

Ermmm. not really. Anything you disconnect will show up on VAGCOM, whether it was working fine or not beforehand.

 

For some particular sensors (mainly the damn MAF) you have really only one option - swap it and see if the car behaves differently. OBD1 isn't very good at diagnosing faulty sensors, unless they're actually electrically broken.

[CorradoVR6-Turbo 0]

Ermmm...

 

Yes i know that...but it shows that the current sensor/ switch is connected correctly and VagCom recognises that its there or not.

 

If you have anymore that 15 degrees the ECU will recognize it as part throttle.

 

Have you had the inlet manifold or throttle body and bent the damper? keeping the throttle open slightly?

[VRTrickster 0]

Ive adjusted the throttle pot, but hasn't changed anything! Its not the reason why its cutting out or running rough. I'm probably going to get a fuel pump relay next week anyway as there are cheap, and then get the fuel pressure tested. Would a faulty relay cause it to cut out? On my vag com the injector on time has been showing 3.90-4.10 ,could this mean that if the fuel pressure is insufficient the ECU will increase the fuel rate like what I'm seeing?

[-Neil- 0]

got my two dfault codes info...

 

00537 - Lamba

11-I0 - Control Unit

Not reached

Intermittant

 

---------------------------

 

00561 - Mixture Adaption

15-00 Adaption limit (add) not reached

 

 

 

can anyone help me what these mean?

[VRTrickster 0]

I have had those two codes also whilst it has been running bad. Ive just ended up spending another £40 quid on a cam position sensor which hasn't made much difference! :mad:

I think its going to be fuel related and I hope after carrying out a pressure test I can diagnose the problem and rectify it before I run out of money!

[dr_mat 0]

So fuelling is off, OR lambda is mis-reading. If fuel economy sucks, it's probably the lambda at fault. If not, it could be your MAF, your ISV, faulty injectors, fuel pressure .. all sorts of funky shit. Keep testing, keep scanning the codes ..

[-Neil- 0]

Forgot to say that my mate found that one of the wires for the lamba was broken which was causing the lumpy idle and the stalling at junctions. He connected this wire again and now its fine, when coming to a halt or coasting to a junction the idle still slightly blips slightly but not nearly as bad as it was before, and doesnt stall any more.

 

It still reads those two faults codes tho after connecting the wire again.

 

My mate says that the sudden judder when eccelerating at low revs might be if u dont have much fuel in your tank, and it sucks in air as its an in-tank pump.

 

anyone else any ideas?

[dr_mat 0]

It's all fuelling related, by the look of it. I would ignore mates who guess things like "fuel pump sucking in air" though, frankly .. ;)

Did you reset the codes and they came back? Or are you saying it's still not right?

Thing with the VR. To diagnose stuff like this you've either got to swap everything till you find the broken part, or you have to sit there with a computer and an oscilloscope trying to manually figure out which component isn't sending the right info to the ECU. It's not so easy ..