UR Quattro flat spot - Page 3

Thebishop · 28-02-19, 11:55 PM

Thanks I'll give that a go.
Is it just a case of disconnecting the ecu and cleaning all the connections on the ecu side and the SCART type connector ? And clean with a cloth or something?

Hanuman · 03-03-19, 12:33 PM

It's a WR, so fuel is related to the mechanical displacement of the metering flap for engine load, with input from the control pressure regulator on the left side of the block to the top of the fuel distributor. (The two long braided lines to the alloy lump located below and behind the injector cooling fan.

There's the WOT switch which acts to remove the control pressure regulation when on full throttle. Hence you must have a working throttle switch, and a working solenoid valve at the back of the engine bay.

There is no input to the fuel pump. It simply pumps fuel at a rate above that needed, and the excess is returned to the tank. It just pumps.

Performance Adjustment via the ECU is rudimentary only. This is why it is essential that the fuel system be working as specified.

If the boost gauge is erratic, its likely a failing sensor on the ECU. As a gauge, it's a 'nice to have', but not essential. An overboost condition sensed by the ECU is your only concern- it's a hard cut of the ignition when boost is excessive, and quite alarming when you first experience it.

Thebishop · 03-03-19, 01:26 PM

Thanks for the response so what's my next step as I said car seems to be driving perfectly. It's just that the boost gauge is all over the place.

Clean the connections on the ecu?

Sorry I'm not very mechanical.

Thebishop · 03-03-19, 01:33 PM

Also just to mention the top engine temp sensor had a poor connection as it snapped off so I have one ordered from Quattro corner. I presume this would effect the running or explain the erratic boost gauge.

Hanuman · 03-03-19, 02:29 PM

That temp sensor won't affect the boost gauge.

The ECU is up under the right side of the dash, bolted to the lower assembly plastics.

I've heard tales of the sensor failing, but I've never seen it. The hose to it goes via a filter/vapour trap. Just take a look to see if the hose is secure, and the connections are clean for now. One thing at a time while you get your bearings. It's a slow process of elimination.

A pic of the broken sensor would be good. Some are very basic connections, and corroded connectors abound at this age.

Thebishop · 03-03-19, 02:56 PM

Thanks will keep u up dated won't be doing much for a few wks as am on crutches at the minute

Thebishop · 03-03-19, 03:02 PM

Can I also ask brake dust shields are they same fitting size etc for the 20v & the 10v?

BackintheFold · 03-03-19, 03:10 PM

>>Sorry I'm not very mechanical.
I'd suggest you doNT touch the ecu. It's an expensive part to break!

03-03-19, 12:33 PM	#22
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,006	It's a WR, so fuel is related to the mechanical displacement of the metering flap for engine load, with input from the control pressure regulator on the left side of the block to the top of the fuel distributor. (The two long braided lines to the alloy lump located below and behind the injector cooling fan. There's the WOT switch which acts to remove the control pressure regulation when on full throttle. Hence you must have a working throttle switch, and a working solenoid valve at the back of the engine bay. There is no input to the fuel pump. It simply pumps fuel at a rate above that needed, and the excess is returned to the tank. It just pumps. Performance Adjustment via the ECU is rudimentary only. This is why it is essential that the fuel system be working as specified. If the boost gauge is erratic, its likely a failing sensor on the ECU. As a gauge, it's a 'nice to have', but not essential. An overboost condition sensed by the ECU is your only concern- it's a hard cut of the ignition when boost is excessive, and quite alarming when you first experience it. __________________ I wish they would keep the damned Chinese away now that I can go home, so that I can enjoy Fish amok and a draught Angkor

03-03-19, 02:29 PM	#25
Hanuman Trickster Classic Audi Club Member Join Date: May 2009 Location: Heckling from the cheap seats, Phnom Penh, KoW Posts: 7,006	That temp sensor won't affect the boost gauge. The ECU is up under the right side of the dash, bolted to the lower assembly plastics. I've heard tales of the sensor failing, but I've never seen it. The hose to it goes via a filter/vapour trap. Just take a look to see if the hose is secure, and the connections are clean for now. One thing at a time while you get your bearings. It's a slow process of elimination. A pic of the broken sensor would be good. Some are very basic connections, and corroded connectors abound at this age. __________________ I wish they would keep the damned Chinese away now that I can go home, so that I can enjoy Fish amok and a draught Angkor

28-02-19, 11:55 PM	#21
Thebishop Grown up member Join Date: Jan 2018 Posts: 40	Thanks I'll give that a go. Is it just a case of disconnecting the ecu and cleaning all the connections on the ecu side and the SCART type connector ? And clean with a cloth or something?

03-03-19, 01:26 PM	#23
Thebishop Grown up member Join Date: Jan 2018 Posts: 40	Thanks for the response so what's my next step as I said car seems to be driving perfectly. It's just that the boost gauge is all over the place. Clean the connections on the ecu? Sorry I'm not very mechanical.

03-03-19, 01:33 PM	#24
Thebishop Grown up member Join Date: Jan 2018 Posts: 40	Also just to mention the top engine temp sensor had a poor connection as it snapped off so I have one ordered from Quattro corner. I presume this would effect the running or explain the erratic boost gauge.

03-03-19, 02:56 PM	#26
Thebishop Grown up member Join Date: Jan 2018 Posts: 40	Thanks will keep u up dated won't be doing much for a few wks as am on crutches at the minute

03-03-19, 03:02 PM	#27
Thebishop Grown up member Join Date: Jan 2018 Posts: 40	Can I also ask brake dust shields are they same fitting size etc for the 20v & the 10v?

03-03-19, 03:10 PM	#28
BackintheFold Senior Member Classic Audi Club Member Join Date: Feb 2019 Location: Near an MB ur Quattro Posts: 1,171	>>Sorry I'm not very mechanical. I'd suggest you doNT touch the ecu. It's an expensive part to break!