I am beaten

[DEREKCO]

Ok guy I am beaten my 93 Audi coupe s2 ABY , The car starts and ticks over sweet after about 2 to 3 minutes you can hear the engine note change ,the exhaust starts to pop and the tickover drops , if I try and throttle up the cars is strangled also a fuel smell from exhaust, this is what I have done
Vagcom scan showed 00513 (we know about this one )
00525 & 00537 I changed the lambda sensor
I changed the spark plugs
I changed the fuel filter
I changed the temperature sensor on the back of the head
I cleaned and checked the MAF sensor.
NO JOY THE BLOODY CAR STILL WILL NOT BEHAVE

WHAT AM I MISSING HELP ?

Anyone who lives near me could you pop around and point me in the right direction I live in Consett CO.Durham . Cup of tea is waiting .Derek

[DEREKCO]

I am beaten

I also vacuum checked the FPR it holds vacuum (got a new one ordered) will change it anyhow

[piotr]

Is the engine actually starting to misfire??Could be sticking injector or faulty coil.if it is misfiring,then find out which cyliner and we go from there.(swap injector and see if the fault move with it)

[DEREKCO]

I am beaten

Engine does not misfire when throttling ,it has ran fine until Thursday night I got in the car it started fine then the fun started the fault has appeared suddenly no warning.

[S2TORNADO]

Did you change the spark plugs or clean them?
Have you disconnected a cylinder at a time to see if it's down to 1 (or maybe 2) or the whole lot?
If it is an isolated cylinder you can them swap around plugs/packs to see if the problem "moves".

[simon20vq]

When it conks out have you checked to ensure there is fuel pressure in the injector rail still?

[AndyP]

When it conks out have you checked to ensure there is fuel pressure in the injector rail still?

I'd be trying this, once the engine start mis-firing, switch it off and crack the bolt at the end of the fuel rail. Make sure you have a rag around it because if you do still have good pressure the fuel will squirt out. Or you could climb in the boot and see if you hear the sound of the fuel pump change as the car starts to mis-fire.

[mike74]

My one used to run a bit funky and occasionally conk out...there was a strand of metal on one of the engine speed sensors! Worth a look as they're easy to pull out and clean

[S2TORNADO]

Sounds to happen too consistently to be a faulty fuel pump. That's either terminal or more intermittent.

Probably need to determine whether it's down to a single isolated cylinder or across the lot. That'll help lead to the source.

[DEREKCO]

I am beaten

Ok have spent 7 hours on the car
Fuel filter changed
New plugs fitted (took them out today and all are sooty)
Lambda probe renewed
Fuel pump checked
MAF sensor checked and cleaned also plug checked and pins
ISV removed cleaned and tested OK
Crankshaft sensors removed cleaned refitted
Throttle position sensor checked also plug and pins
New temp switch fitted (the one behind the head)
Air filter removed ( temporary)
Started engine unplugged MAF engine stopped
Vacuum tested fuel pressure regulator holds vacuum (got brand new one coming tomorrow)
Car starts first time and idles sweet for 2-3 mins then starts lumpy tickover
Try and give it some throttle no way it strangles it ease throttle off tickover improves slightly but not perfect just lumpy
The only illustration I have is like leaving the choke on ,on my old mini
HELP HELP

[S2TORNADO]

Have you tried to isolate it to a particular cylinder yet?
I expected the plugs to be dirty and or wet.

[andyg plym]

I'd try another known maf , appreciate it visually looks ok but I had months of similar issues to yours and it didn't show any codes for it but I tried one off a mate and fixed it straight away....

[piotr]

When it starts to run rough,start to unplug injector plugs one at the time and look for change,this should give us idea if it's one of cylinders or more

[Sleeper_Avant]

same issues I am/was having with my URS4,

stopped revving past 4500rpm, not a misfire but wouldn't rev higher.

Cat had collapsed!

run it with the 02 sensor unbolted so the exhaust has a hole in and see if it helps.

Sean.

[macspring]

I'm tending towards an ignition fault.

Is it oem coils of TFSI coils?

If it is oem substitute a good pos and see does that cure it ? Could still be an oem coil of the oem coils wiring.

As has been mentioned, you do need to determine which cylinder is at fault by unplugging each injector in turn to see if / which cylinder(s) is messing.

If you can borrow a set of TFSI coils and loom would allow you to also check the ignition.

HTH.