VR6 not starting - SOLVED

[v11boy 10]

Hello forum!

I’ve got a 1995 VR6 which isn’t starting, although it was running recently but has now decided not to start. If I’ve put this in the wrong place I apologise!

So far I’ve checked earth connections/fuses/some relays/ignition switch (new one tried, same issue). Vagcom suggested 00513 engine speed sensor G28 although that could be due to the engine not running as per Rosstech image. However this seems like a logical place to go next.

When looking to clean the connecting plug, I noticed the black yellow cable in the first picture above is just hanging, & I can’t see where it fits. Can anyone confirm where it goes please?

A) cable leading to connection for engine speed sensor

B) black yellow spade connector joined to this cable, before it gets to the connector block

C) end of loose (yellow black cable) spade connector.

the image with the fan housing shows a close up of the connector.

Any guidance appreciated!

Thanks

Edited March 20, 2021 by v11boy
Title changed after diagnosis

[v11boy 10]

Ok - I’ve spoken to a mate who has just popped his head under the bonnet (a running Corrado) and confirmed this is a lone cable, not plugged into anything!

back to looking for the problem, next step is clean the connection of engine speed sensor, then replace if no good - unless anyone can suggest something which may be better!

cheers 🍻 

 

 

Edited March 6, 2021 by v11boy
Words wrong

[Cressa 44]

I believe the yellow black cable is only used if you are lucky enough to have the VDO gauges as this is for the oil pressure sensor that would be fitted.

The usual non starting suspects are a dodgy immobilizer ( what do you have) or possibly the ignition switch which is a ball-ache to change, but cheap enough and a reason for 'working then not'.... if nothing else has been touched 

Good luck anyway 👍

[v11boy 10]

4 minutes ago, Cressa said:

I believe the yellow black cable is only used if you are lucky enough to have the VDO gauges as this is for the oil pressure sensor that would be fitted.

The usual non starting suspects are a dodgy immobilizer ( what do you have) or possibly the ignition switch which is a ball-ache to change, but cheap enough and a reason for 'working then not'.... if nothing else has been touched 

Good luck anyway 👍

Ah thanks for that!

Ive tried a new ignition switch first which didn’t work... although when I did it I used a screwdriver rather than a key to turn switch, will that make a difference?

it’s got an aftermarket immobiliser fitted, made by Directed Electronics... as far as I can tell it’s operating the same as it did when it ran, and the vagcom isn’t showing any issues when you dig into the immobiliser measuring blocks.

the fun will continue 🤦‍♂️🤣

[Cressa 44]

I don't believe an aftermarket immobilizer would show up on VCDS as it has been stuck on afterwards. 

It's always a good challenge sorting a non starter

[Philly-R6 0]

If your engine is cranking on the starter motor, but not running - it will be either no spark or no fuel.

Whip a spark plug out and does it smell of fuel?

While its out can you see it spark?

 

The fuel pump is turned on by the Engine control module, through a relay on the fusebox (position 12). The power is fused (fuse 16 - from memory).

When the ignition is first turned on, the fuel pump is pulsed. Note: Checking for 12v across the pump isn't simple in this scenario. When the engine is cranked, the fuel pump is then turned on.

You are best using a 12v bulb (or preferably an LED) on wires so you can see power across the fuel pump.

 

If you have spark and the fuel pump wiring seems ok, you could have a stuck fuel pump (hit the underside of the tank and see if you can free it off), or your fuel filter could be blocked?

 

 

Your factory immobiliser is Immobiliser 1 - which is what you see in VCDS - there is a transponder in the key: Immobilizer - Ross-Tech Wiki (ross-tech.com)

Where this immobiliser is a problem, the car starts and cuts out after a second or so...

 

Good luck and report back with your findings.

[v11boy 10]

39 minutes ago, Philly-R6 said:

If your engine is cranking on the starter motor, but not running - it will be either no spark or no fuel.

Whip a spark plug out and does it smell of fuel?

While its out can you see it spark?

 

The fuel pump is turned on by the Engine control module, through a relay on the fusebox (position 12). The power is fused (fuse 16 - from memory).

When the ignition is first turned on, the fuel pump is pulsed. Note: Checking for 12v across the pump isn't simple in this scenario. When the engine is cranked, the fuel pump is then turned on.

You are best using a 12v bulb (or preferably an LED) on wires so you can see power across the fuel pump.

 

If you have spark and the fuel pump wiring seems ok, you could have a stuck fuel pump (hit the underside of the tank and see if you can free it off), or your fuel filter could be blocked?

 

 

Your factory immobiliser is Immobiliser 1 - which is what you see in VCDS - there is a transponder in the key: Immobilizer - Ross-Tech Wiki (ross-tech.com)

Where this immobiliser is a problem, the car starts and cuts out after a second or so...

 

Good luck and report back with your findings.

This is pure gold thank you. I will report back

[Dox 23]

Crank and watch the tacho on the dash, if it moves off its stop its seeing the crank sensor

[Dox 23]

Factory immobiliser is on the same fuse as the spoiler, if the spoiler can be raised there should be power to the immobiliser too.

[v11boy 10]

Hello all

I’ve tried a few things tonight and confirmed -

no spark

rear spoiler works when ignition is on

connections to crank sensor are clean

Relay in position 12 looks perfect when covers removed 

all fuses in board by relays are good

as mentioned above, Ive tried a new ignition switch first which didn’t work... although when I did it I used a screwdriver rather than a key to turn switch, will that make a difference?

any suggestions of what to try next appreciated!

Thanks 🙏 

 

[tonedef 9]

19 minutes ago, v11boy said:

Hello all

I’ve tried a few things tonight and confirmed -

no spark

rear spoiler works when ignition is on

connections to crank sensor are clean

Relay in position 12 looks perfect when covers removed 

all fuses in board by relays are good

as mentioned above, Ive tried a new ignition switch first which didn’t work... although when I did it I used a screwdriver rather than a key to turn switch, will that make a difference?

any suggestions of what to try next appreciated!

Thanks 🙏 

 

When you tried the new ignition switch with a screwdriver, did you have your key in the reader coil for the immobiliser? That may have prevented it starting, long shot maybe, as mentioned above immobiliser faults are normally identifiable as the engine fires and starts to pick up revs before cutting out.

[Cressa 44]

7 minutes ago, tonedef said:

When you tried the new ignition switch with a screwdriver, did you have your key in the reader coil for the immobiliser? That may have prevented it starting, long shot maybe, as mentioned above immobiliser faults are normally identifiable as the engine fires and starts to pick up revs before cutting out.

Oooo that is a great suggestion 👊

[v11boy 10]

49 minutes ago, tonedef said:

When you tried the new ignition switch with a screwdriver, did you have your key in the reader coil for the immobiliser? That may have prevented it starting, long shot maybe, as mentioned above immobiliser faults are normally identifiable as the engine fires and starts to pick up revs before cutting out.

That’s a plan! Will give that a go.

Thanks for the input!

Edited March 9, 2021 by v11boy
Forgot text

[Dox 23]

On 3/6/2021 at 9:04 PM, Dox said:

Crank and watch the tacho on the dash, if it moves off its stop its seeing the crank sensor

Does it crank / turn over?

[fla 9]

Check and if necessary replace your ECU relay 109. This shuts off sparks and injectors. Also check relay 167 (may be labelled 67). This is your fuel pump relay.

[v11boy 10]

With the key in reader coil and new ignition switch plugged in, it again won’t start.

it turns over but will not fire.

Rev counter does not move when it’s turning over.

relay 167 and 109 look good!

As there is no spark, would crank sensor be the next logical place to go?

thanks all!

Edited March 10, 2021 by v11boy
Mistake!

[easypops 8]

I would agree with Fla, I’ve had 2 non starting VR6’s and the very first thing I’ve done each time is swap ecu and fuel relays. I’ve been fortunate that I’ve had known good relays to hand. Both cars started but I’m unsure which relay was at fault.  I couldn’t see anything wrong with the above relays and I wouldn’t know what to look for if I’d opened them. Definitely worth trying. Maybe you’ll have someone close by you could borrow from? 

[fla 9]

I would remove and test 109. Apply and hold power on it. If it is failing you won't get a spark. If its failing it will.buzz as the circuit opens and closes

Crank sensors are pricey so you don't want to change one in a rush! If you can borrow one that would be great.

I would then check wiring to your coilpack, and the coilpack itself, if you're not getting a spark. Maybe borrow a replacement from someone if anyone is local?

 

Edit: Sorry Easy, I'm repeating your advice!

 

Hasan

Edited March 10, 2021 by fla

[Dox 23]

29 minutes ago, v11boy said:

With the key in reader coil and new ignition switch plugged in, it again won’t start.

it turns over but will not fire.

Rev counter does not move when it’s turning over.

relay 167 and 109 look good!

As there is no spark, would crank sensor be the next logical place to go?

thanks all!

If your scanner connects and code reads the ecu it's powered up so 109 is working? No movement on tacho suggests crank sensor - the ecu doesn't know the engines position so wont inject fuel or spark. Where abouts are you? Someone local may be able to loan you a crank sensor

[v11boy 10]

Ah ok thank you all.

my mate down the road has another one (rado vr6) so I’m going to be talking to him nicely about borrowing relays and possibly the crank sensor. 

Thank you!

[v11boy 10]

109 / 167 Relays tried from a working rado vr6, with no joy.

ignition is nearly new (heritage part), was running fine after fitting at Christmas. I’ve removed it, checked and plugged back in again 

can smell fuel during starting and can hear pump priming so that side seems fine.

was looking to replace crank sensor next with one from heritage as attached.

Have I missed anything?

Thank you 

[Dox 23]

If its injecting fuel into the cylinders the crank sensor is working?

[fla 9]

Did you check fuel at the injectors? Of the fuel pressure regulator is faulty it will come to the rail but not the injectors

If the plugs are wet then you're ok for the fuel circuit.

Sparks - take one out and, connected to the lead, get someone to crank the car while you rest it on the block and see if you're getting a spark. Check all 6. If they're all sparking it may be the spark is not strong enough. Did you say you'd changed the plugs?

[fendervg 33]

Faulty hall sender can cause no spark - it will be a separate part beside the coil pack, or part of the distributor on early cars - worth checking. Do the spark test above first if you can. You can use a jump lead to earth a spark plug back to the block - can be easier than holding it.

[Dox 23]

23 minutes ago, fendervg said:

Faulty hall sender can cause no spark - it will be a separate part beside the coil pack, or part of the distributor on early cars - worth checking. Do the spark test above first if you can. You can use a jump lead to earth a spark plug back to the block - can be easier than holding it.

I thought a faulty cam sensor gave long cranking but still started?