VR6 Codes and running rough

[edition 0]

Hi,

 

I’ve done a Vr6 conversion into my mk2 golf. The car starts and drives but idle is erratic and if you put it under load it stutters then clears.

 

 

The car has done a fair bit of starting and idling and not a lot of running.

 

I have added a photo of the error codes that I have.

 

Any help would be much appreciated.

 

Thanks

Edited August 12, 2018 by edition

[Dox 22]

You'll get a crank sensor code on these engines if its not running at the time of the scan.

[1200 bandit 10]

Looking at the codes,possible wiring not corniced to the sensors/no feed to the sensors,

Check wiring to the sensors,(from injection computer to sensors)

[edition 0]

Does anybody have any readings that I should be getting at each wire?

 

Thanks for the help so far!

[edition 0]

I’ve checked the Lamba plug odb1 oil pack engine.

 

Yellow = Ecu pin 27

Brown = earth

White = ecu pin 20

Red/white = earth

 

Is the red and white meant to be to earth?

[edition 0]

Also the car runs like his from cold... I believe the lambda doesn’t work until 70 degrees?

[Dox 22]

If you suspect a misfire, with the engine running disconnect and reconnect each plug lead in turn, make a note any removed where the engine note doesn't change as theres a problem with that cylinder.

 

I'd do it at the coil using insulated pliers

[edition 0]

I’ve taken each plug off and it runs much worse on each one...

 

I have noticed that the car runs better for a while if you take the ecu off and put back on against

 

 

Any ideas?

[vw rule 19]

According to the Corrado Bentley manual for VR6

the lambda sensor has 4 wires,

it says to check for pre heat voltage with your multimeter set at 20v.

 

terminal 1 (red / white) wire,

terminal 2 (brown) wire.

 

Says you should see approx battery voltage with engine running (basically 10 to 12 volts)

 

So if the (red / white) wire and the (brown) wire were both earth, then you wouldn't see any voltage between terminals 1 and 2.

 

I believe the lambda sensor normally pre heats when the engine is cold, then when the engine / exhaust is up to temp, it will obtain it's heat then from the hot exhaust or something like that.

 

So possibly the (red/white) wire terminal 1 is the power feed for the pre heat circuit, and the (brown) wire terminal 2 is the earth.

Possibly the red / white wire switches to earth so as to turn off the pre heat circuit, once the engine / exhaust is up to temp, which is normally after 10 to 12 minutes.

 

The manual also says VR6 with coil pack from mid 1993 to 1994 has 1 lambda sensor.

Then from 1994 upwards VR6 with coil pack has 2 lambda sensors.

 

 

Si

Edited August 18, 2018 by vw rule

[edition 0]

All the o2 and maf wiring seems to be correct.

 

Does anyone have a 4 working pin maf they would like to sell?

[fla 9]

Any change in engine note when you disconnect the maf sensor?

[edition 0]

It doesn’t seem to no....

[fla 9]

Ok so either the maf is faulty or the wiring to it. I assume you've cleaned it with sime carb cleaner? If not it might help

[edition 0]

One thing to note is that I’ve not got the fuel vapour solenoid fitted. Could this cause issues?

[fla 9]

Not quite sure what you're referring to there?

[vw rule 19]

Do you mean the fuel vapor canister purge valve

?? If fitted to VR6 ?

 

Si

[edition 0]

Yes.

[vw rule 19]

Possibly could cause an issue unless you've blanked off the vacuum hoses.

Looks like the fuel vapor purge valve recirculates, the vented off fuel vapor / deposits from the fuel tank, via the carbon canister, which is fitted under the air filter box right behind the front bumper on drivers side, the purge valve it's self is situated on the side or back of the air filter box, very similar to where it is on the 16v Corrado's.

According to the Bentley manual the purge valve (EVAP) solenoid value, opens once the engine is up to temperature, so I presume it must communicate via the ECU with the coolant temp switch.

If the fuel vapor purge valve (EVAP) fails or the vacuum hoses are not fitted, then it can cause rough running / idle and poor starting, like I say according to the Bentley manual.

It also says that the fuel vapor purge valve is an emissions control device, as it helps to lower the emissions.

 

Si

[edition 0]

I guess it’s worth putting it back then and seeing if it makes any difference.