VR6 Engine Fails After 12 Minutes

[daveme 0]

I have a problem with my 1993 VR6 Corrado. After driving it for 12-14 minutes from cold, the engine loses power and stops. Trying to restart it fails (the engine turns over but doesn't fire up) until about 5 minutes later when it restarts and I can continue my journey. Occasionally it fails again within 200 yards, but normally it continues OK. If it does fail again within 200 yards then it normally restarts fairly quickly.

 

I've taken it into a garage for investigation but they are currently stumped. Trying to find an intermitent fault when you only have a short window to investigate it is causing a bit of a headache. They seem to think the ignition is not the problem since having connected a small LED to the ignition, when the engine fails the LED still flashes. They have also replaced the sensor that detects the piston positions to control the igniton timing but that also hasn't had any effect.

 

Any thoughts would be much appreciated. Thanks

 

Dave

[andy 0]

Anything in Vag Com?

[RW1 0]

I suggest you have a look at the engine speed sensor (G28) on the front of the lower engine block under the oil cooler. They are expensive to buy so if you can borrow or get hold of a known good one and substitute.

 

It won't show easily in VCDS (VAGCOM) because of the nature of the fault code and how it behaves in the diagnostics. Capturing this fault (00513) genuinely is hard at the best of times as it also shows when an engine is stopped.

 

This is how you do it.

 

Given the engine problem is like clockwork at 12 minutes...... At this point do this.... Bit of a 2 person job as one needs to operate VCDS very quickly and the other crank the engine continuously.

 

Bit of a difficult procedure to do practically because instructions below must be done exactly as written so the fault memory is interrogated at the right point where an engine speed sensor (G28) fault code 00513 is genuinely the sensor, not registering the engine is just stationary.

 

- Switch the ignition back on as the engine stop problem occurs and at not time during this test switch the ignition off again until the end. Otherwise VCDS will choke and stop working, invalidating the test below.

 

- Start cranking the engine and keep it cranking on the starter motor.

 

- Set VCDS into 01- Engine and enter into fault codes. DTC 00513 will be the fault memory. Clear the fault.

 

- Back out of fault screen to the ECU screen with the screen buttons including "Fault Codes".

 

- Re-enter the fault codes screen while the engine is still cranking. Has the fault code reappeared? **

 

- Stop the cranking but don't switch off the ignition.

 

- Exit VCDS.

 

- Switch off ignition.

 

** If the DTC00513 was visible when the VCDS Fault Codes is re-entered while the engine is still cranking, the engine speed sensor (G28) is faulty.

 

.

[fla 9]

have you/they tried replacing the ecu relay no 109? Does it start if you waggle the ignition switch around a bit. Forget the led test, the engine can crank, hence show power but may not fire if the switch is faulty. These are 2 cheap fixes (around £12 for the relay and about £15 for the switch from VAG)

[zak 0]

when it dies does the engine still turn over and does it does it sound any different ie does it spin over faster?

[Kevin Bacon 5]

They have also replaced the sensor that detects the piston positions to control the igniton timing but that also hasn't had any effect.

 

This needs clarification. As yours is a 1993, it's in the Dizzy / Coilpack change over period. Which one is yours? If it's a coilpack engine, you need to ask the garage if they replaced the crank sensor, or the cam sensor.

 

If yours is a Dizzy, then ask them if they replaced the hall sensor, or the crank sensor.

 

The show stopper sensor is the crank one, and they are about £130, so you would remember seeing that on the invoice. You can do what RW1 describes above, or remove a spark plug and check it arcs. Neither the injectors or the coils are energised if the crank sensor is dead.

 

Old tired fuel pumps can also exhibit the problem you describe.

[Reggit 0]

VCDS will show an intermittent crank sensor (at least it did last time I scanned a car with a faulty one) as a seperate entry to a 'no signal error' that you get when the engine is stopped.

[daveme 0]

Thanks for all your replies.

 

I got the car back from the garage last Friday after they had changed a relay. They seemed reasonably confident they had fixed it, but without testing it over a few days/weeks they couldn't be sure. Since then I have driven it 4 times and each time it has been OK. Hence, fingers crossed, I'm hoping things are now OK. In fact it does seem smoother, although that may just be me thinking it is smoother.

 

With regards the fix, I'm not sure what relay they changed. When I get the bill I will post the part number. With regards the error codes generated by the ECU, the garage didn't seem to think any of them were relevant.

 

I'll let you know what has been changed when I get the bill.

 

Dave

[Jon_vr6 1]

Got to be the ECU or Fuel pump relay glad you got it sorted fella