Can you please look at this.. Fuel pump filter issue??? (Pics inside)

SupraClaou

Supramania Contributor
Sep 1, 2006
846
3
18
Athens,Greece
Hi guys! Just installed two new walbro 255ltr/h GSS341 HP intank pumps.
I wanna go to tune my car to higher boosts and I want my fuel pumps to be fresh!

After the installation I noticed quite lean conditions on my A/F aem gauge.
My car is tuned to high 11's (11.7-11.8) at 14 psi of boost on my 72mm turbo.
I was getting readings of 12s...and dometimes 13's under boost :aigo:
Also my fuel pressure couldn't reach it's peak value vs boost. I am having 5-8
psi drop in FP , and I think this caused the lean conditions.

I checked the vacuum lines,FPR,fuel lines,fuel filter,everything looked ok.
When I took my fuel pump hanger out to inspect the fuel pumps today I saw this:
'The filter of the 1st fuel pump was bent upwards...maybe due to bad installation
and lack of space (for 2 pumps) into the fuel tank'. The bent filter might cause bad restriction
to fuel flow as well as fuel sturvation...'my two cents'.

I think that this might be the reason of fuel pressure drop and lean conditions..
What do you guys think? :cry:
Also,I fill up my fuel tank till the middle 1/2 ,to keep my total weight
down. Lately I was doing some street racing :naughty:

p1737666_1.jpg


p1737666_2.jpg
 
Last edited:

bioskyline

New Member
Oct 21, 2010
1,236
0
0
powell river bc
looks like it hit the anti spash well wall in the tank. will take a bit of fooling around and twsiting to get it in right spot, but thats a 3d fileter, and will suck gas from top and bottom, so not to critical.

also were you running twin pumps before? or is this new? afrs were ok before the new pumps??
 

mirage83

Member
Mar 21, 2008
457
0
16
Georgia
Have you run new wiring and relay for those pumps? If not you might want to go with the 12-volt mod to drive the pumps with what you have in mind for the car. At least that way you'll know you've got plenty of current to run the pumps at full capacity.
 

SupraClaou

Supramania Contributor
Sep 1, 2006
846
3
18
Athens,Greece
bioskyline;1737675 said:
looks like it hit the anti spash well wall in the tank. will take a bit of fooling around and twsiting to get it in right spot, but thats a 3d fileter, and will suck gas from top and bottom, so not to critical.

also were you running twin pumps before? or is this new? afrs were ok before the new pumps??

No..it is almost a 2 year twin pump setup. Since I went big single. But my last pumps had 2 short filters..
The new pumps came with one shorter and one longer filters.
AFRs were ok before!

---------- Post added at 01:33 PM ---------- Previous post was at 01:28 PM ----------

Maybe the pump sucked a quite amount of the pressurised intank air.. cause everytime I was trying to turn the ignition key on
I was waiting 3-4 seconds for the AEM to make it's checks, I was getting a gurlgling sound behind the firewall where the FP regulator
is located... Usually I was hearing only the sound of the walbros.

---------- Post added at 01:41 PM ---------- Previous post was at 01:33 PM ----------

mirage83;1737684 said:
Have you run new wiring and relay for those pumps? If not you might want to go with the 12-volt mod to drive the pumps with what you have in mind for the car. At least that way you'll know you've got plenty of current to run the pumps at full capacity.

No...I haven't. I run them through stock wiring.
I was thinking about the 12V mod,but at the moment I though it was not necessery since I boost only 14 psi....
 

bioskyline

New Member
Oct 21, 2010
1,236
0
0
powell river bc
the tanks are vented so they dont pressureize or create vacuum, though lack of gas isnt good. i always run my tank from full to 1/2, as fuel weight is not that much, and the fuel also cools the pumps, so i keep them submerged.

the filters on the pumps are just to keep dirt and junk out of the pump. if the old filters look good and not to dirty, just re-use them if there shorter. can also clean them with compressed air.

id to the 12v mod and see if it helps, only other think i can think of is one of the pumps is weak and not keeping up.
 

mirage83

Member
Mar 21, 2008
457
0
16
Georgia
SupraClaou;1737685 said:
No...I haven't. I run them through stock wiring.
I was thinking about the 12V mod,but at the moment I though it was not necessery since I boost only 14 psi....

You'll want to do the mod. It's cheap insurance as the stock wiring doesn't carry a lot of current safely, and with the extra fuel volume you're looking for out of that upgrade pump you want to make sure that you don't lean out due to the pump not being able to keep up.
 

toyotanos

What will we break today?
Staff member
Super Moderator
Nov 29, 2008
2,841
2
38
Coon Rapids, MN
About the wiring- I am running a 8AWG amp wire that splits to 2 12awg wires (and seperate relays triggered by the stock wiring) feeding each pump with an 8gauge ground wire for my a aeromotive 340 pumps! Overkill- maybe, but fuel pumps love good clean battery voltage and you're choking them by using the factory wiring. Also, the factory wiring is 14gauge at best so 2 walbros will pull enough power from that wire to make it get warm-maybe even hot!

Do yourself a favor and run some new wires to the back of the car to feed your starving pumps :p

Also, you'll have to rotate the pumps so that both pickup socks lay as flat as possible- this is nother thing that can caused problems by making the pump suck air and making the other pump work harder.
 

te72

Classifieds Moderator
Staff member
Mar 26, 2006
6,603
2
38
40
WHYoming
One more thing to consider, check your fuel lines. Albert on here was having a real issue with his fuel system, turned out to be a bent/kinked fuel line.
 

SupraClaou

Supramania Contributor
Sep 1, 2006
846
3
18
Athens,Greece
Guys... issue solved!
Kept the existing walbros while they were almost new and never thought they could be the problem...
And got two new pump filters that were installed better this time without bending or any issue of that nature.

AND PEOPLE...I did change the wiring setup. Pumps now get powered directly from the battery (+12V)
I will make a new thread about stock toyota wiring,that is in fact not capable to power correctly 2 high performance pumps.

p1741256_1.jpg


p1741256_2.jpg


---------- Post added at 10:14 AM ---------- Previous post was at 10:12 AM ----------

Now I get a steady FP and A/F ratio around mid 11's ..and after 5K drops to 10.9 !
I am a very happy person!