I Have A New Toy............. URS4 Avant

[twoqu]

The only other observation is that the fuel pressure would be more or less correct for the 26-28psi that the SW allows according to the PO. So that implies that the FPR is seing that level of boost whilst your boost gauge is not. Where is the boost gauge teed in?
I would leak test as recommended on here by pressurising the system with air through the MAF hose and removing and blanking the pcv hose from the cam cover. That way tests everything.

[Kieron20V]

The boost gauge definitely reads 27-28 psi when it's running correctly. And nothing has changed since then other than it being parked up for about 5 weeks

Sent from my Nexus 6P using Tapatalk

[Sleeper_Avant]

https://www.youtube.com/?hl=en-GB&gl=GB

Fixed.

[LHD_Kid]

The link just takes me to my youtube home page?

What was the issue?

[Kieron20V]

http://youtu.be/YdpMOM_wHqk


Seriously? Have you driven it with it off? If so I suspect what has happened then is that the crap running from being sat with lots of over fueling, paired with the weak coils has torched the cat with all the fuel basically and blocked it up.

Good excuse for a deposit cat I suppose... I don't get how this was causing it to cut the fuel pump though??

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[Sleeper_Avant]

I guess the back pressure was causing it to cut out,

if I could see MAP/MAF readings I would have concluded this on day 1 of diagnosing it!

The cat had been obviously damaged by the gearbox caused previously due to engine mountings being no good, it is a fair old don't in the cat housing.

I just smashed the granny out of it so now it is hollow, runs so much better, idles quieter, boosts up to 25 ish PSI so hard and sounds very aggressive I cant wait to drive it next Friday.

Since I have not got to but any more bits, well except a good Idle valve, I will be on the market for a white faced Wideband gauge I think.

Oh and maby a Go Pro camera (or any other suggestions?!)

It sounds like a jet when it comes on boost!

[Sleeper_Avant]

[Thuppu]

Can't see properly from the vid. So the core was molten/clogged?

[Sleeper_Avant]

No Thuppu, it was loose from where the housing was banging off the gearbox,

it was so loose it was virtually 45degree angle inside when I too it off.

you can see from the pictures above how bad the impact was

[newsh]

Awesome

[quattrostyle]

Good thing it was something 'simple' I was afraid you were loosing faith in the car already

[Sleeper_Avant]

I was losing faith, nothing made technical sense!

Because I could not see MAP/MAF values it dragged on too long,

On a lighter note I did everything I wanted to do as "preventative maintenance" such as:
Cam sensor
RPM sensor
Fuel pump Rewire and Relay upgrade
General health check

Sell some unwanted/in needed items

Buy some goodies to fit at a later date!

It sounds mental now, cant wait for next friday

[Sleeper_Avant]

Small update,
I mustered up energy to leave the house again yesterday and forced myself to play with the S4.

Stripped rear brakes and brake greased them all up.

Fixed a split in a front cv boot with Tiger Seal.

Swooped a TCA washer as it was wrong way round and did a spanner check on whole car.

Just needs oil change, fuel and geometry alignment.

I don't think I have done a full spec list of the car have I?

I might also do a new thread, thaughts on this?

Cheers!




Car even has a stud conversion! I keep forgetting all of the little details that make this S4 a special car, and why I bought it without seeing it

[Sleeper_Avant]

well, I was all legal to drive last Friday and all excited to drive the S4!

But all was not well and the old original issue of cutting out under load popped back again when on the motorway at 62mph/3000ish rpm

I was gutted and lost all love for the car, hence not posting on here and adding up what it was worth to break into spares etc (yes I was that down about it)

but decided I must fix it for my own sake.

So I spent most of Monday re-checking EVERYTHING I had already done,
20 minute smoke pressure test confirmed no leaks.
TPS scrutinised and all tested fine.
Idle valve replaced 3 times, no issues there!
Voltage to engine sensors/inputs all good.
Coloration between cam and RPM sensors all good as seen on oscilloscope.
Reference sensor still in place and again, same checks as above.
Metal tube inserted into Intercooler to TB hose as it was soft and incase it was collapsing, no change.
O2 sensor removed, cleaned refitted and tested ok (plug was loose fitting, tightened clearances and it ran worse afterwards!! obvious poor connection there)
MAF sensor checked out all ok resistance wise etc

Wiring to ECU now to be checked:
Everything was perfect continuity wise, earths, wiring plugs all removed, cleaned and greased then refitted.

Nothing makes sense and I am going round in circles getting more and more annoyed both at the car and me for buying it instead of another Cosworth......

Then I notice that the wiring on the MAF plug didn't match with the documented pictures online,
I asked another forum member for a pic of his and again the pic I received was the opposite of my plug.

I thaught fk it so I re-pinned the plug to where it should have been and boom, started instantly, no black smoke or bad idle!!

NO WAY!!!!!!!

I knew instantly it she was fixed.

So jumped in and went to put some fuel in (AGAIN!)

Drove a million times better, responsive, boosting, generally lovely to drive

so once she warmed up and had a drink I fed in some loud pedal

jeez, only in 2nd gear she pulled harder than a teenage boy in an empty house lol

I think the MAF is shagged as out of 4 or 5 hard rev/boosts 7000rpm/27psi it didn't boost 2 or 3 times until I cycled the key.

But I am happy now and will post some videos tomorrow

Sounds awesome and cannot wait to get it into 3rd/4th gear tomorrow

Now I can get on with some upgrades to the car:
Air Conditioning retrofit (Not Climatronic, just basic AC I think)
Lowering springs
Wheel and tyre upgrade
Have replacement wings painted and fitted
give car a good tidy up

oh and upgrade the sound system!

Regards a very very happy Sean

[bazburn]

well, I was all legal to drive last Friday and all excited to drive the S4!

But all was not well and the old original issue of cutting out under load popped back again when on the motorway at 62mph/3000ish rpm

I was gutted and lost all love for the car, hence not posting on here and adding up what it was worth to break into spares etc (yes I was that down about it)

but decided I must fix it for my own sake.

So I spent most of Monday re-checking EVERYTHING I had already done,
20 minute smoke pressure test confirmed no leaks.
TPS scrutinised and all tested fine.
Idle valve replaced 3 times, no issues there!
Voltage to engine sensors/inputs all good.
Coloration between cam and RPM sensors all good as seen on oscilloscope.
Reference sensor still in place and again, same checks as above.
Metal tube inserted into Intercooler to TB hose as it was soft and incase it was collapsing, no change.
O2 sensor removed, cleaned refitted and tested ok (plug was loose fitting, tightened clearances and it ran worse afterwards!! obvious poor connection there)
MAF sensor checked out all ok resistance wise etc

Wiring to ECU now to be checked:
Everything was perfect continuity wise, earths, wiring plugs all removed, cleaned and greased then refitted.

Nothing makes sense and I am going round in circles getting more and more annoyed both at the car and me for buying it instead of another Cosworth......

Then I notice that the wiring on the MAF plug didn't match with the documented pictures online,
I asked another forum member for a pic of his and again the pic I received was the opposite of my plug.

I thaught fk it so I re-pinned the plug to where it should have been and boom, started instantly, no black smoke or bad idle!!

NO WAY!!!!!!!

I knew instantly it she was fixed.

So jumped in and went to put some fuel in (AGAIN!)

Drove a million times better, responsive, boosting, generally lovely to drive

so once she warmed up and had a drink I fed in some loud pedal

jeez, only in 2nd gear she pulled harder than a teenage boy in an empty house lol

I think the MAF is shagged as out of 4 or 5 hard rev/boosts 7000rpm/27psi it didn't boost 2 or 3 times until I cycled the key.

But I am happy now and will post some videos tomorrow

Sounds awesome and cannot wait to get it into 3rd/4th gear tomorrow

Now I can get on with some upgrades to the car:
Air Conditioning retrofit (Not Climatronic, just basic AC I think)
Lowering springs
Wheel and tyre upgrade
Have replacement wings painted and fitted
give car a good tidy up

oh and upgrade the sound system!

Regards a very very happy Sean

Good to see you back on it Sean