Naughty 'Valver - Relay 30? Update5 - VAG-COM Results

[Stirring Moose]

Dear old 'Valver is up to tricks again. Current game is lumpy idling and bad/rough response to rapid throttle opening. Will run clean enough if throttle is opened slowly though. Had a good rummage around using Search and, as a result, have given the Idle Stabilisation Valve a good clean and lubricate and fixed a leaking vacuum pipe to the ECU. Seems to have improved things a little but not a complete fix. Am now in the process of changing the coil pack. During my Search, I came across numerous references to the infamous Relay 30, the ECU relay. Couldn't really get a clear picture of whether or not it might cause these problems though. Anyone got any thoughts on this?

S.M.

[dub-gti]

change the relay and see what happens,

use vagcom to see if it throws any codes up

[Screech16v]

Dear old 'Valver is up to tricks again. Current game is lumpy idling and bad/rough response to rapid throttle opening. Will run clean enough if throttle is opened slowly though. Had a good rummage around using Search and, as a result, have given the Idle Stabilisation Valve a good clean and lubricate and fixed a leaking vacuum pipe to the ECU. Seems to have improved things a little but not a complete fix. Am now in the process of changing the coil pack. During my Search, I came across numerous references to the infamous Relay 30, the ECU relay. Couldn't really get a clear picture of whether or not it might cause these problems though. Anyone got any thoughts on this?

S.M.

I had the exact same symptoms,was the first thing i changed relay 30,perfect afterwards 

[Stirring Moose]

Sounds like the hunt for relay 30 is on then! I'll let you know how it goes. Thanks guys.

S.M.

[Stirring Moose]

Ok, changed Relay 30. It wasn't Relay 30  Thanks for the suggestion anyway. Back to Search for me unless anyone can throw in any other bright ideas. To recap, she's now had: ISV clean, repaired ECU vacuum pipe, new coil pack, new Relay 30.

S.M.

[Leon27]

I had a similar problem with my car and found a few faults along the way that might help you. Try and get it scanned if you haven't done so and check the status of the coolant temp sensor. These can muck about and cause all sorts of problems.

The wiring running around the back of the head to the throttle position sensor and idle switch can get toasty and melt as they sit over the exhaust manifold - check for broken wires there.
Crankshaft sensor wiring also tends to break up and this is visible allbeit with difficulty from under the car around the oil filter area. If theres a crack in the protection it might be worth it to check it further.
Leads - General cracking?
Earths - Under the battery tray especially
2x vacuum pipes - 1 from the inlet manifold to the PCV (square box with 2 breather pipes attached) 1 from inlet to the Fuel Pressure Regulator - If you changed the other one then these two might need changing as well depending on their condition. When you said you repaired the ECU vac pipe, did you change it? They can block up internally - this would normally cause a MAP fault to be stored though. Remove the pipe from the ECU and see if air can be passed through easily.

My fault was weird - caused by the alternator overcharging intermittently which in turn activates a overcharging protection circuit built into Relay 30 to protect the ECU. When it happened, the idle was rough, hard acceleration was especially rough, sometimes the fault didn't occur at all! Maybe worth seeing if you have a good steady 13-14 volts on idle with the fault present.

See what happens with that, hope it helps a bit

[Mellls]

Hi, I had similar problems, everything pointed to Relay 30 and it worked for me.

This may sound stupid, but I did it even after being warned  :embarassed: .... Did you get them mixed up and put the old relay back in instead of the new one?

[Stirring Moose]

@Leon 27: Wow! That's a fair old list to work through. We'll see if she responds to any of it but, either way, thanks for taking the time to put that lot together.

@Mellls: Luckily the old relay was black and the new one was white so chances of confusion minimal! One person who did seem confused was the VW parts guy. Asked for Relay 30 and he had no idea what it was. So asked for it as the Digifant Control Unit relay or somesuch and he was straight on it. Relay duly appeared... with a big black "30" stamped on it 

S.M.

[jinx]

My old valver went like this a while back, changed the usual relays,  including the fuel pump relay, but didn't work.
Checked all the vac lines, breather tubes and the crank sensor,  but in the end it turned out to be some faulty wiring, not round the back to the TB, but the part round the front where the injectors are.  So have a look there when you exhaust all options.

[Stirring Moose]

Quick update. Haven't managed to do any more to the car yet BUT have managed to get the car undercover for a bit and put a blower heater under the engine to dry things out a bit. This seems to have improved things a bit - certainly not cured as yet but better. This is making me suspect wiring/connection probs so will probably tackle that next.

S.M.