extra fuel pump probs

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
with my bt setup i fitted a extra fuel pump (bosch 044) at the front of the car as a temp measure to get it mapped, was very noisey as i coundnt rubber mount it.

i have since tried to fit the pump at the rear (on rubber mounts) and car sometimes wont run, surges on part throttle and is still noisey ?

pump is brand new, i have even tried a mates new pump and its the same

any ideas anyone ?
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
have you checked your fuel pressure with a gauge?
is it rising and falling?

i am starting to think it may be something to do with the power supply ? gonna try it with power direct from the battery and miss the relay etc

if i get no joy with that and will be on the hunt for a gauge to test the pressure;) cheers
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
have you checked your fuel pressure with a gauge?
is it rising and falling?

just had the gauge on, tickover with the TT pump is around 40 psi

then fitted the bosch 044 with a direct power supply (no relays) and the pressure goes off the gauge @ 100 psi ? :blink:

its quiet but its still surging with the extra pump and nearly cutting out, it runs perfect with just the TT pump
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
just had the gauge on, tickover with the TT pump is around 40 psi

then fitted the bosch 044 with a direct power supply (no relays) and the pressure goes off the gauge @ 100 psi ? :blink:

its quiet but its still surging with the extra pump and nearly cutting out, it runs perfect with just the TT pump

fpr cant cope with all that extra flow then can it.. stock size lines to and from rail?
you are checking pressure on inlet to rail?

100psi is *cough* stonking pressure! yikes
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
fpr cant cope with all that extra flow then can it.. stock size lines to and from rail?
you are checking pressure on inlet to rail?

100psi is *cough* stonking pressure! yikes

yep standard lines, gauge fitted to inlet of rail before fpr

it was going off the gauge past 100psi:whistle:

i am runnung with the TT pump now and its fine ? we couldnt read my afr thru vagcom, dont know why, but the exhaust gas temps are around 800 at the redline
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
extra flow not possible to recir back perhaps... so bottlenecking the rail to its excessively high pressure

egt's measured off your lambda heaters or actual egt sensor in hotside?
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
extra flow not possible to recir back perhaps... so bottlenecking the rail to its excessively high pressure

egt's measured off your lambda heaters or actual egt sensor in hotside?

mines a bam engine with a extra exhaust temp sensor in the downpipe, i think the exhaust temps are measured thru that ? if not its the lambda

i can blow thru the fuel return line quite easily
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
maybe the size of the fuel pipe thats the problem

you could have a point;)

when i had the pump mounted at the front it ran 8mm rubber hose from pump to the fuel rail then oem return pipe,

now the pump is at the rear it has to run thru the factory pipes from fuel filter at rear to engine bay - rubber hose to fuel rail then oem return pipe
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
think i have sussed it ( cheers for the idea bill ;))

temp fitted extra pump =

2008_0405Image0003.jpg


took fuel return off engine =

2008_0405Image0001.jpg


and fitted it direct back into tank =

2008_0405Image0002.jpg


car is running sweet, no surging, no trying to cut out, no crazy fuel rail pressure,

it would apear my return line is kinked/damaged and unable to cope with the fuel return of the 044 pump
 

ibizacupra

Jack-RIP my little Friend
Jul 25, 2001
31,333
19
glos.uk
good news.. mad max style plumbing.. :D

think of my 2 x 044's. -8 line to rail(s), -6 line returning - fingers crossed
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
good news.. mad max style plumbing.. :D

think of my 2 x 044's. -8 line to rail(s), -6 line returning - fingers crossed

:lol: eye the plumbing wasnt pretty was it, i was a tad sick of fitting it all up to test different things and having to take it all back off again :censored:

i can fit it all nice now and fingers crossed it wont have to come back off

your plumbing = :headhurt:

Glad you got it sorted mate.

cheers mate, it was starting to do my head in:cry:
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
Glad it looks like it's sorted. One question, is your tank vented?


cheers dave ;)

ermm i am fairly sure it is :think:

it has a few extra pipes to and from the filler neck ( is that where the vents would go too ? )

you cannot see where they all go to after the filler neck tho, unless i was to drop the tank
 

DPJ

...........
Dec 13, 2004
7,996
2
NN Yorks / Salento
www.seatcupra.net
cheers dave ;)

ermm i am fairly sure it is :think:

it has a few extra pipes to and from the filler neck ( is that where the vents would go too ? )

you cannot see where they all go to after the filler neck tho, unless i was to drop the tank

I was just wondering if the situation would be different on yours with the cap on your tank. Vent from the tank should come forward to the carbon canister. When I removed my evap, I did first try just blocking the vent and it built up a lot of pressure in the tank.....
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
I was just wondering if the situation would be different on yours with the cap on your tank. Vent from the tank should come forward to the carbon canister. When I removed my evap, I did first try just blocking the vent and it built up a lot of pressure in the tank.....

my polo never had a carbon canister (originally a 1.2ltr, 3 cylinder engine)

it only has 2 pipes to front of car fuel in/return ?

will keep a eye on any tank pressure build up ;)
 

ceedubya

crazy legs
Mar 18, 2004
130
0
newcastle upon tyne
I have had a chance to fully inspect the oem fuel lines i took off ( taken off in the dark )

they look in perfect condition, no signs they were kinked or damaged ?

has anyone else had to change the oem fuel lines running the same pumps as me = TT in tank pump + bosch 044 / 3 bar fpr
 
Chris Knott Insurance - Competitive quotes for forum members