Egr valve non start question.

[billynoband]

Sorry to bother people with another egr valve/engine valve shut off question as I know so much has been written on this. My 05 altea 1.9tdi bjb engine stalled and turns over but would not restart. I find I can only get the car to run if I pull the pipe off the nipple of the egr valve. I cleaned the unit but it made no difference, I fitted a second hand unit (yea, I know) but have identical symptoms and cure. I have a p2102 fault code showing. I don't understand why pulling the pipe off makes the car work.

[zollaf]

can only presumee you are pulling the pipe off the anti shudder valve, as the egr won't cause a non start but the asv will. they are both in the same unit. so for some reason you have a vacuum to the asv when you shouldn't.

[Flash2]

I could be wrong but I don't think you'd get a 2102 code if the engine has a vacuum operated ASV. But it does sound like there is vacuum being applied to the EGR valve when it shouldn't be pulling the valve open. Perhaps the EGR control solenoid is leaking or perhaps it's being switched on when it shouldn't be. You'd need to check the wiring at the solenoid block to see if there is a ground on the EGR control wire. If that checks OK then it sounds like the solenoid valve is leaking and will need replaced.

Jim.

[billynoband]

There are no wires to my egr unit as it is a bjb code engine. I have replaced the unit and the fault is the same.

[Rob69]

Are you pulling the pipe off the big silver diaphragm unit on the top or the small black one on the side of the EGR housing? The small one is the anti shudder flap, spring to open vacuum to close, the big one is the EGR. Sounds more like the anti shudder is closed while trying to start the engine. No airflow across the MAF giving you the P2102 code

[billynoband]

I mean the small black one on the anti shudder valve. The confusing thing about my problem is that the anti shudder valve is open when starting the engine with the pipe connected or not. It will only start and run with this pipe pulled off though.

[billynoband]

can only presumee you are pulling the pipe off the anti shudder valve, as the egr won't cause a non start but the asv will. they are both in the same unit. so for some reason you have a vacuum to the asv when you shouldn't.

Yes , I have only just realised this. If I put the anti-shudder valve pipe back on with the engine running then the arm of the valve slowly shuts resulting in the car stopping. So there is a vacuum when not needed. Does anyone know if the signal is from the ecu. I have replaced the valve assembly but it made no difference.