Fueling problems?

[martinjs]

For the last few weeks ive been having problems with hesitation cutting out etc, thought it was down to using optimax as it ran ok on bp ultimate but no-one else has been having similar problems so suspected something else was a miss. well today it all went **** up , ive spent the last 5 sodding days fitting konis, got finished today and the thing wouldnt start.
thought it'd got damp, sprayed wd40 everywhere, spark was there, plug was wet with petrol so thought must be damp, towed it off and started ok but wouldnt tick over on its own.:mad:
so went for a drive not letting it fall below 2k rpm, wont accelerate over half throttle just cuts out, did about 15 miles and eventually started to idle on its own blip the throttle and nearly cuts out. still wont boost over 0.3bar, will start on its own but only after 10secs or so.
it looks like the earlier problem i had with it not boosting over 1.3bar has got a lot worse, definately feel its fuel related.
question is:-
will a dodgy fuel pump cause this, does the pressure between the pump and the fpr remain constant or between the fpr and injectors remain constant? thought it could be a dodgy pump struggling to fuel over 1.3bar, so now is struggling to feed over 0.3bar since its not been started for a while.
ill be changing the fuel filter tomorrow.
where the hell is the fuel pump on a 3b coupe, thought it was screwed into the top of the tank like in dougs pics of his motorsport pump installation but it isnt.
is it under some heatshield or something?

sorry for the rant but i have to be back in london on monday
:wacked: :mad:


martin

[Doug_RS2]

Martin - did you lift the metal fire shield floor in the boot?

The fuel pump access is under that fake floor. You need to peel off the carpet that is stuck to it at the back, a few bolts at the back and 3 (IIRC) at the front. You can then lift that sheet of metal up and get access to that fuel pump.

[Greg_S]

I reckon the FPR would be a good place to start also. Easier to take out and check that as a starting point.

[martinjs]

cheers doug, greg, just going to change fuel filter now, got some IPA today also so will soak the maf overnight coz ive never looked to see how clean it is, im using a k+n too

[dan_b]

Martin - when my fuel pump went this summer, it literally just failed with no warning. That's not to say it's not a problem on yours though - have you noticed any whining noises from the rear of the car (ie noisy fuel pump)?

The pump is in the tank as noted above.
Check the fuel pump relay, and also the state of your fuel filter - another thread here described the state of their old filter as a "fossil"!

A plea Martin - could you give me instructions on how you removed your 3B MAF and cleaned it? I need to do it to mine too as I have a suspicion I have a dirty MAF as I occassionally get a herky jerkyness on low-RPM pickup/after gear changes.

[martinjs]

well dan, just replaced the fuel filter, it started ok, didnt go for a drive though, but it was still a bit lumpy, the fuel pump (yes found it thanks) has definately started to whine too, this could be the cause. yippee
i took the maf out, the screen (turbo side) has already been removed at some point, the screen filter side is jet black, take it this is not a good sign
so its in soma IPA at the mo', dont have a camera to hand but it is dead easy to remove, took me about 5 mins,
remove the heatshield next to airbox. 13mm socket on long extension will reach the bottom bolt next to turbo, then 2x bolts holding it to airbox,
then theres just 2 clamps holding the maf to the airbox, 'at 9 + 3 o'clock' to each other, take these off and thats it.

ps, does anyone have the bosch part number to hand for the fuel pump?
how much do they go for?
i may have to try and get one early monday morning before the trek back to london:wacked:

pps, dont squirt petrol in your eye it fecking kills:wacked: :wacked: :wacked:


martin

[martinjs]

Forgot to say dan, got some IPA from the chemist
£3 for 600ml, so bought 2
just enough to submerge it in bowl im using

HTH

[newsh]

Sometimes the fuel pump whines when the filter is blocked then settles down again with a new filter.

Maybe go for the uprated pump if you're going to replace it though, eh? Worth it if you're doing power mods, I'm told.

Give the MAF connector a good clean too.

Are you sure you've not got an air leak somewhere?

[newsh]

From the 500 hp thread, someone's had the bosch number off though:confused:

[Mark Halligan]

From the 500 hp thread, someone's had the bosch number off though

Yeah I noticed that too, cant think why .

Anyway that looks a lot like the same one that Doug and I have installed, Bosch P# 0580 254 044.
Specs are: 200 l/h fuel delivery at 5 bar pressure, Bosch page here .

You also need to install it in a different reservoir mount, Audi P# W895 201 779H along with the bottom half/strainer P#895 201 531A.

Full details can be found in Doug's
420 +bhp project .

Although don't use the pressure damper as it appears to be the wrong one, a 12x1.5mm Dome does the job nicely.

Cheers,

Mark.

[marty]

Be careful when ordering etca gives wrong numbers, for my 3b anyway iv got an 8AO 906 091 G from vagparts when i came to change it its only about half the size of whats in 895 906 091 A.
Mine only makes a noise no runing problems just wanted to change it before it lets go in the middle of no where.

[dan_b]

When my fuel pump went, I was told that the "standard" Audi part for the 3B S2 coupe had modified, and as a result there was a 2-week delay in parts. I ended up getting it from GSF.

I hope it fixes your problems! I'm going to check out my MAF next free afternoon I get, thanks for the guide!

[martinjs]

if i did use an uprated pump will i need an uprated fpr too?
im still using the stock one with RS2 injectors.
it could be a duff fpr though as greg says couldnt it?
how can you test this?
think ill just join the AA now, in case i breakdown in the morning..lol

[martinjs]

i swear this cars got a mind of its own, after changing the fuel filter and cleaning the maf it was still cutting out when going over 1bar, was like this for a few days!
until today, now its back to rocket ship status, i thought it may be the fuel pump, think it is fuel starvation at over 1bar, could it be an intermittent fault with the fpr? how can i test this is working at over 1bar boost?
cant be a boost leak!!:wacked:
mihnea...could that 1111 fault code be contributing to this?
ive got a spare fpr somewhere, so could try that.
is it worth fitting a 7a one?

:wacked:

[martinjs]

Just pulled code 2121...could this be contributing?