From Audi 100 to urS4 in a week

[ringbearer]

I had a chunk on cat stuck in the last bend of the muffler. Remove the exhaust from the cats back and test it out.

[hunker7]

Unfortunately car isn't still pulling well, the same issue with the revs not going over 5k. Car runs better generally but it's just when you get to high revs/speed.

MFTS seems to be playing up, as sometimes it works sometimes it doesn't, but MFTS isn't the one giving ECU the info is it? I've ordered a new lambda sensor, as I couldn't find any records of that being changed and car has done over 180 000 miles. Fuel consumption is bad too, regardless of how I drive 16mpg is the best I can do around town.

Can exhaust be blocked anywhere else apart from catalysts and middle silencer?

[hunker7]

Just to you know, when the 1.8t coil pack failures first started to show up, it was Bremi who had made the defective coils. If I remember correctly the VAG folks held Bremi's feet to the fire and made Bremi re-supply new coils to VAG at no cost to VAG. (But that is from memory, going back to 2004/05).

These are from V8, and also, i hope they learned from their mistakes

[UrS4boy]

Just to you know, when the 1.8t coil pack failures first started to show up, it was Bremi who had made the defective coils. If I remember correctly the VAG folks held Bremi's feet to the fire and made Bremi re-supply new coils to VAG at no cost to VAG. (But that is from memory, going back to 2004/05).

[hunker7]

Good news! (for once)

Runs much much better with the fuel line sorted now. Goes over 4k in 5th easy, but need someone who knows these cars to drive it, to tell me if it's running 100%, but it's good for now

Didn't like the way car was on idle, so got set of new coil to trial and it's much better, so I'll send the used ones back.

On top of that, got a quote from LongLife for exhaust, £450+VAT for decat, downpipe onwards. Sure they sent me a picture of the S6 Plus Spink was breaking

[hunker7]

After some time managed to sort the fuel pipe the, wish me luck

I had a suspicion that compression is low (9 bar) because of bad starter motor, but I started the car on 4 cylinders and it's still low. So, I put some oil in the cylinder and compression went up by 2 bar. So I have no choice but to open up engine over summer and do the shells and rings, and hopefully upgrade rods as I am planning on many torques in next couple of years.

[UrS4boy]

G61/G66 Knock Sensor Information

Might be a daft question, but how does the engine know that's it "knock"?

Piezoelectric signal(s) from the G61 and G66 knock sensors

G61 and G66 Knock Sensor Info:

http://forums.quattroworld.com/s4s6/msgs/21047.phtml

[hunker7]

It will go lean, knock and the ecu will retard ignition and try to add more fuel, it will basically just hold back.

Might be a daft question, but how does the engine know that's it "knock"?

You're blessed that it is as 'simple' as this, the car should be much improved once you resolve this.

Looking forward to your post after it's fixed.

I am now trying to figure out how to sort it tomorrow.

[UrS4boy]

It will go lean, knock and the ecu will retard ignition and try to add more fuel, it will basically just hold back.

*DING*

Perfect diagnosis.

[macspring]

You're blessed that it is as 'simple' as this, the car should be much improved once you resolve this.

Looking forward to your post after it's fixed.

[newsh]

It will go lean, knock and the ecu will retard ignition and try to add more fuel, it will basically just hold back.

[hunker7]

Thanks, I'll see what I can do why doesn't it shake when there isn't enough fuel?

[UrS4boy]

Not f'ed up completely. It is twisted though. ill see if I can get it sorted 17mm socket was involved because I was trying to take it apart,unsuccessfully.

NO. It is completely Fk'd man. This is your problem: fuel restriction under high demand.

Re-check my post. I edited it to include a photo and a link.

[hunker7]

Not f'ed up completely. It is twisted though. ill see if I can get it sorted 17mm socket was involved because I was trying to take it apart,unsuccessfully.

[UrS4boy]

C4 UrS Fuel System: From the Tank to Injectors and Back Again

If there was a fuel deficit wouldn't there be shaking when there isn't enough? Only thing is this that I noticed couple of days ago, the inlet pipe is squashed

Twisted? Mangled? Fk'd up behond all recognition (Fubar'd)?

The good news is you have found your problem.

The bad news is you have to fix it. (and you need that double-flared end). Why is a 17 mm socket involved?

C4 UrS Fuel System: From the Tank to Injectors and Back Again:

http://forums.quattroworld.com/s4s6/msgs/226410.phtml