HELP vr cut out on motorway at 70

[lexxuss 0]

hello all,

my vr scared the nuts off me today, i was crusing along m/way

@ 70 and decided to coast it as i was going downhill. dipped the clutch in and the revs dropped to about 500 then cut out. :shock: i quickly bumped it off in 5th and carryed on driving. when i got off the m/way i tried it at 40mph and car idled fine. have tried this at different speeds and it seems that if im doing anything more than 60mph the car will not idle when i dip the clutch. :roll:

 

apart from that the car seems to runs fine. any ideas guys, isv perhaps.

[lexxuss 0]

wot no ideas

[JBOB 0]

Im not sure what the problem is sorry, but im just wondering why you would dip the clutch and coast @ 70 mph !!!!!!

[lexxuss 0]

well tbh i was seeing if the cutting out was speed dependent and it is. car never cuts out at low speed or pulling up to junctions like ive heard others do, its just at higher speeds.

[dr_mat 0]

The cut-outs tend to be dependant on the revs the engine drops from when you dip the clutch, not the actual speed you're doing.

That said, no-one's ever figured out a definitive answer to this problem. First port of call should be VAG-COM, though.

If you ain't scanned it, we have no suggestions..

[Jim 1]

Just a forewarning.. I know it might not be practical to do this if the engine cuts out at an innapropriate time again, but try and avoid bumping your VR6 back into starting where possible. Instead, restart the engine off the key and proceed as normal! The VR6 does not like being bump started (from the various things i've read on here over the years) and can apparently lead to some kind of engine damage!

 

Not sure on the specifics, but sure that its a bad thing!

[Kevin Bacon 5]

The only danger with VR6 timing gear is sprocket teeth jumping. Assuming the tensioner pads and guide rails are OK, then jumping will only happen (potentially) if there is no pressure in the tensioning bolt. If the engine is not running, then positive pressure will be cut but due to the fact the bolts have non-return valves that need manually relieving, oil pressure remains, enough to keep the upper pad tensioned......so the risk of causing damage by bumping a VR is minimal, very minimal. I've done it several times with no adverse affects.

 

The chain gear is more than engineered enough for the odd bump, and anyway, bumping is not particularly nice for ANY engine, not just VRs, as it puts a lot of strain on CVs, gearbox etc aswell....

[Jim 1]

Cool ok Kev.. was just making sure cause i'd heard so many times that bumping a VR wasn't a good idea, but thanks for clearing that little myth up :)

[RW1 0]

Cut-out like this (or at lights or roundabouts) is likely to be caused because "BASIC SETTINGS" on the ECU has not been performed following a battery disconnect. Therefore the throttle body and Engine ECU aren't aligned. Seems to happen on the Corrado VR6s (particularly on distributorless late models) due to the low idle rev point combined with overrun. It somehow looses the exact idle position and before the ECU can recover the situation, the engine stalls. (This assumes that the engine is generally in good fettle and particularly the ISV is operating normally [no fluctuating revs at idle - 680 rpm [650 - 750rpm is normal but must be rock solid on whatever revs]])

 

Carry out the second half of the ECU reset procedure covering basic settings in Knowledge Base. No need to perform the battery diconnect and drive procedure.

[dr_mat 0]

Not wishing to sound disbelieving, but which part of the basic settings bit is required? My VR has been reset without performing any post-reset configuration of the ECU many times (due to flat batteries or other work on the car) and has never shown this problem.

The Corrado VR6 has no electronically controlled throttle valve, so I assume you're talking about the ISV adaptation values?

[dinkus 10]

Surely dipping the clutch and coasting when you're doing 70 isn't a good idea in the first place tho?

 

"it hurts when I do this"

"well don't do it then"

 

:)

[RW1 0]

Dr Mat.

 

The first half of the procedure is purely to get the Lambda probe idle, mid and high rprm range settings bedded in quickly as they are lost on loss of electrical supply to the ECU. The ECU does some of this in the first 10 minutes then adopts a monitoring/ fine adjustment from then on but it does take upwards of 30 mins to determine all three preset "offset" values to the ECU map in the ECU memory. So Basic Settings shouldn't really be performed immediately after a battery disconnection, allowing at least one hour of driving before hand.

 

The second part of the procedure harmonises the ECU to the sensors and the importantly the throttle position sensor. Doesn't have a motorised throttle persay but it still needs to know where the throttle is. Some VR6's don't seem to bothered but others do, so presumably it's a tolerance thing. The most noticable effect of this procedure is the accelerator dead spot at idle is minimised and the true VR6 sweetness is acheived.

 

*************************************************************

ie. this part of the precedure:

 

ENGINE ECU BASIC SETTING

 

Start and warm engine to normal operating temperature. Ensure engine oil temperature is above 85øC (185øF). Ensure Air Conditioning and other electrical loads are switched off, including the radiator cooling fan (NB Does not matter if radiator fan operates during “Basic Setting” 2 minute period.)

Connect the VAG 1551 to diagnostics socket located in centre console, to the front of gear shift lever under the cover surround. Ensure no Diagnostic Trouble Codes (DTC) are stored for the engine ECU. Let the engine run at closed throttle - idle (typically 640 - 690 RPM). Operate VAG1551 using the following sequences and observe the displays:-

 

VAG1551: Select address word - 01 (Engine) VAG-COM: Select 01 - Engine

Key 04 - Basic Setting, press Q to confirm entry. Select Basic Settings - 04

Key 0012 - Display group 001, press Q to confirm entry. Key 0012 - Display group 001, press “Go!”

System now in “Basic Setting”. System now in “Basic Setting”.

Increase the engine speed to 2,500 rpm for 3 seconds. Increase the engine speed to 2,500 rpm for 3 seconds.

Allow to idle for 2 minutes. Check CO level. Allow to idle for 2 minutes. Check CO level.

When radiator fan is NOT running, Press , 06, Q When radiator fan is NOT running, “Done, Go Back”.

 

 

Motronic M2.9 ECU Group 001 Motronic M2.7 ECU Group 000

Field 1: Engine RPM - 680rpm (Allowable 650–750rpm). Field 1: Coolant Temperature - 185, below 210

corresponds 85øC to 99øC

Field 2: Coolant Temp.- above 85øC, typically 92øC/98øC. Field 3: Engine RPM - 65, below 75,

corresponds to 650 – 750rpm.

Field 3: Active Lambda - 1.00 + 0.2 Field 10: Ignition Timing - 85 to 91,

slowly fluctuating +0.02 max, corresponds to 4ø to 8ø BTDC.

2 second period, typically.

Field 4: Ignition Timing - 6.00ø + 1ø, fluctuating slightly.

 

(2 Motronic ECUs at M2.7 software standard use group 000 for “Basic Setting”, ECU part no. 021 906 258B, BF, CC )

 

(2 Motronic ECUs at M2.9 software standard use group 001 for “Basic Setting”, ECU part no. 021 906 258AG & CP )

 

(NB. Basic setting places the ECU into a specific offset condition from which the engine sensors can be measured.)

 

*********************************************************

 

Basic Settings is in the 20,000 or 40,000 miles VW service schedule (can't remember off hand), so the technician after finishing all other tasks should perform this before returning the Corrado to the owner. (Not the Battery disconnect though!).

 

It never does any harm to do it on a Corrado VR6 but cut the procedure short of what is written and stalling may be even worse as the ECU hasn't sampled enough data points.

[Supercharged 2]

and the true VR6 sweetness is acheived.

 

Some great wordage there...

[Kevin Bacon 5]

http://www.ross-tech.com/vag-com/tour/b-settings.html

 

VR6s are renowned for poor idling. The sudden drop in gas speed of the throttle snapping shut sometimes overwhelm's the ISV, which if binding (many do due it's location, heatsoak) can cause a stall. VW attempted to delay the throttle snapping with a dashpot, so try winding that up a bit. It's the orange rubber belows with plastic piston behind the throttle lever.

 

If you can push the white piston down more than a mm with the throttle at rest, it needs raising a bit.

[lexxuss 0]

thanx for all the replies :thumbleft: , sorry havnt responded till now jus got back from work. will deff try the basic settings procedure as the ecu has been reset after i replaced the hall sender and o2 sensor.

have checked vag and got no error codes and have tried adjusting the throttle dashpot which helped but didnt cure it.

 

hopefuly i will hear that vr6 sweetness after doing basic settings. . .