could a de cat pipe cause pinking????

[stevef182 0]

as above, having had my de-cat pipe fitted my car in now pinking..the guy who fitted it said there is no way the two could be linked but it seems strange that as soon as its been fitted its now pinking?

it was also feeling a bit sluggish at the bottom of the rev-range so he tested the fuel pressure and it was low so suggested it was the fuel pump causing both problems and a new fuel pump would be the answer, does this sound right??

[flusted 0]

a lean mixture will cause pinking

[boost monkey 0]

Yeah, flusted's right.

 

A de-cat pipe is literally just a straight pipe to replace the cat (as you know); I think it's just coincidence that it happened at the same time.

[stevef182 0]

a lean mixture will cause pinking

 

 

which would be a dodgy fuel pump right? not fitting a de-cat pipe, or can that cause a lean mix?

[stevef182 0]

Yeah, flusted's right.

 

A de-cat pipe is literally just a straight pipe to replace the cat (as you know); I think it's just coincidence that it happened at the same time.

 

must be, the chap who fitted it suggested that maybe the change in the exhaust note meant it was easier to hear the pinking..i dunno..i just want it sorted but am so skint that i cant afford to replace parts that dont need replacing!!!

[boost monkey 0]

Yeah. I would have said looking at the fuel pressure reg too, but a good source informs me that those either work or they don't, so if the car's running the FPR should be ok.

 

Has the timing been messed about with recently, or have you tried a different octane fuel than normal?

[stevef182 0]

Yeah. I would have said looking at the fuel pressure reg too, but a good source informs me that those either work or they don't, so if the car's running the FPR should be ok.

 

Has the timing been messed about with recently, or have you tried a different octane fuel than normal?

 

no not that i know of, the timing chains were done a while back and had no problems, well i presume not anyways, was done before i owned the car and it definately wasnt pinking when i bought it..the only things mechanically i have changed since owning the car are the rad fans, the fuel filter, and the de-cat pipe..have tried 4 types of fuel since it started pinking and it did it with every one so its not the brand of fuel,..had the fuel pressure measured and it only made 3.6 bar so it must be that i guess!

 

just bought a new pump and sender from a guy on here, not quite sure if its the right part or if it will fit as it has a few broken fins but ive got my fingers crossed!

 

do you live in surrey?

[dr_mat 0]

One more point: the lambda probe, which is VITAL for correct fuelling, is intalled in the CAT pipe. If it's been disturbed it may well not be working right any more.

I have to say that usually when you lose the lambda what happens is overfuelling, but if it's been contaminated in a subtle way it may read the wrong way. Also look for air leaks. Leaking post-block and pre-lambda could result in badness.

[stevef182 0]

One more point: the lambda probe, which is VITAL for correct fuelling, is intalled in the CAT pipe. If it's been disturbed it may well not be working right any more.

I have to say that usually when you lose the lambda what happens is overfuelling, but if it's been contaminated in a subtle way it may read the wrong way. Also look for air leaks. Leaking post-block and pre-lambda could result in badness.

 

funny you mention the lambda as i was thinking about that on the way home from work and if it may be causing this problem, when the car was on VAG COM it showed up as having intermittent or no signal..it turned out to be the wiring and got that fixed but was thinking maybe it didnt get fixed properly... :shrug: although after it was fixed no fault codes showed up on VAG COM suggesting that it was working as it should be!

will also check for air leaks, although not really sure where to start! :help:

[boost monkey 0]

No I'm in Oxford i'm afraid matey :salute:

[stevef182 0]

No I'm in Oxford i'm afraid matey :salute:

 

my bad, i thought i saw somewhere you studied or lived in Weybridge, must have been someone else!

my brother is at uni in oxford, nice place!

[paul20v 0]

3.6bar is 51.84 psi how much pressure is a vr meant to have ?

[KipVR 1]

Could be a leak on the plastic bit between the throttle body and the MAF, they often crack where the oil breather joins it, causing an incorrect mixture. I'm thinking they may have rocked the engine excessively and opened up a crack/made one. It's worth a look...

[dr_mat 0]

3.6bar is 51.84 psi how much pressure is a vr meant to have ?

 

The ABV VR engine has a 4 bar fuel rail.