Fuel pressure won't adjust and it's too lean.. need ideas.

[savage1987]

Need 58psi.

on ACC power only it'll prime up the system to 58psi nicely

startup and it's down to 50.


Engine idling, no matter which way I turn the adjuster nut on the SARD reg, nothing happens.. 50psi whole time.

Can't really test drive like this, doesn't like life too much lean :(


Anyone got ideas? I will draw a rough pic of what I'm running and dump it in here for brainstorming

[Nemi]

fuel pump is fucked or the reg is fucked or you have a vac leak.

[savage1987]

No vac line to the reg (which is brand new)

pump might be it - GSS341/2 can't remember - but i REALLY don't want to change another VN-S fuel pump ever :( so I will draw a pic and see if anyone picks up any rookie mistakes I have made.

[Nemi]

clamp the return line and see if you can get more pressure, is you can its the reg.

are you sure the reg doesn't require a vac line ?

[ovaxitd]

as above what jap reg doesnt use a vac??

[Tocchi]

need a vacuum line connected man

[savage1987]

clamp the return line and see if you can get more pressure, is you can its the reg.

are you sure the reg doesn't require a vac line ?


as above what jap reg doesnt use a vac??


need a vacuum line connected man

There is a port on the top of the reg for a vac line, I have been told it is not required; the standard LS1 FPR does not have a vacuum line to it as it is inside the fuel tank, it just sits at 58psi all the time.


I'll clamp the return line and prime it and see what happens. There's a healthy possibility / probability that I have somehow fundamentally fucked up building the fuel system anyway, since this is my first bash at doing one and it's a weird setup converting a return system car to a returnless setup.

[TTZ]

why not just hook up the vac line and see if it solves the problem?

[savage1987]

the reg is back behind the tank, that is one long ass vac line and i don't have a tube that long

[ovaxitd]

ghey... why not use a std fuel reg... the jap ones NEED a vac line into them... dunno how you plan doing that :p

[savage1987]

you know what's REALLY ghey? only comes with instructions in japanese for fitment, and there's nothing on the net that I could find from SARD by way of official fitment instructions in fucking ENGLISH, lol


standard LS1 reg is in-tank, doesn't work so well, pain to set up in a VN tank... or so I'm led to believe. :(

[mitchy]

jap regs are rising rate with boost pressure, thus a vacuum line is required.

[joshg123]

Got a good 12V down at the tank?

[savage1987]

Got a good 12V down at the tank?

Unsure, will check this.


Have spoken to a few people about this, know of a couple of turbosmarts that have been successfully run forever without a vac line... :( well i now have 55psi or just under on idle so should be enough to smash limiter a few times on a test drive round a few of these country roads.

I bet 100% bet if i take it out tonight, drive number 1 I will hit either a roo, or a tree while trying to dodge a roo :p

[indecline]

mate you could try putting the reg in the engine bay so it doesnt have to push the lenght of the car, maybe loosing pressure that way,

[mitchy]

LOL, not enough fuel pressure and keen to smash limiter.

my brother is after some LS1 parts when you're done.

[savage1987]

LOL, not enough fuel pressure and keen to smash limiter.

my brother is after some LS1 parts when you're done.

oi here's a big fuck off to you, you useless pingpingpingping. You have not added any value to this thread, do you REALLY have nothing better to do than chase around after my posts and whinge?

Fuck off.

[RRob]

Its quite a simple setup that everyone is getting confused over.

Setup should be something like this..... Pressure pump feeding fuel rails with a tee piece in the pressure line to a reg bleeding off excessive pressure. Sard regs are fuel in the side port and out the bottom port.

No vacuum line is needed to the reg on fixed fuel pressure setups.

[savage1987]

That's exactly how mine is plumbed.

I'll draw a pic of it to clear things up and see if you think my filters are wrong etc

[beefcake]

yep his system is as most factory cars do these days , return-less systems are the norm.
Id say your reg isn't holding pressure or your pump is too week to feed that pressure.
Is the sard a real genuine unit or is it the myriad of china units .

Either way i think your pump would be the first place to look. but that pump is the hi flow warlbro unit so it should be able to flow the goods, but is that a china unit too , hmmm.
Voltage reg or pump is the only places that could be the problem :confused:

Edit : i would have the filter straight after the outlet from the tank, before the tee piece, as then its filtering all the juice, to the engine and back to the tank :)

[savage1987]

Re: reg
checks out as genuine, I worried about this after I bought it so hunted down all the info on fakers that I could find.

Re: pump
2nd hand Walbro unit, only had 10,000km use in a turbo 3800 commodore, and it checks out as genuine from the VERY little I know about how to tell a fake Walbro.


Re: filter......
Fuck I wish I'd thought of that, lol, I'm running 2 filters :p stupidest arrangement.




this is what I have


http://i534.photobucket.com/albums/ee345/sam_brown_05/my%20VN/LS1%20transplant/FPRsetup-1.jpg

[Zuicider]

lol your a fucken muppet sam

[savage1987]

hahaha yep I fail fuel systems 101.. i should have drawn more pictures before i built this system :(

still, as retarded as it is, the 2 filters won't be causing my reg to be un-adjustable insofar as I can see.


o well I will try 2 things out

1. block off the vac port and see if reg somehow magically becomes adjustable
2. engine running, clamp the return line shut and see if pressure spikes

if not, pump must be the limiting factor
if yes, reg is probably fucked



sound about right?

[beefcake]

even so your two filters aint going to be the problem, as one is on the bleed back (no problem) and one is inline to the injectors, no different to having it straight after the pump except its not going to filter your return fuel if you eliminate the return filter .
If you can its best to just slap one in straight after the pump , one pump is only needed, spose it wont hurt to eliminate the return filter and reposition the feed filter

EDIT : yes block off the return line and see if it maxes out, then and only then you will know if its a pump or reg problem, no lift its your pump faulty , massive lift its your reg faulty . And just temp block it with some flat pliers or such, temp clamping the line and you will know in a second your answer

Forget the vac line test , its got nothing to do with your setup , but capping it will stop dirt an dust getting in

[joshg123]

Regardless of if your pump or reg are new/old/otherwise. Think facts only, the time you assume they are good because they are new/genuine is the time you will get the diagnosis wrong.

Check power and earth at tank,
Check fuel pump free flow,
Check outlet line of reg for flow (very little flow indicates one of the above being a issue, lots of flow indicates reg)

It will be one of the above.

[savage1987]

Thanks guys!

I will cap the vac part to prevent shit going in it.



Test results:

Engine idling I shut off the return line with some big ass pliers, squished it shut completely. Held it shut for ages and no change on the gauge

Voltage check on the pump is the next step it seems, if that checks out OK it's time for a new pump :(

On another note, do I need to upgrade the fuse wiring with a Walbro in there? My fuel pump blade fuse has melted its plastic a bit but not blown the fuse... same with a few of my other fuses in the same panel, probably unrelated and due solely to crusty 21yo wiring, lol.

[beefcake]

that melted fuse mount is normal for commies of that age, heaps do it, getting a new fuse block fitted seems to work fine, but in a happy world yes new relays and wiring and fuses to your pump would be good, but in reality a new fuse block with fuse would suffice .
Failing your elec tests could be the problem but if voltage is good then test your pump again to be sure but it does look to be the pump as the problem so far

Ps the warlbro pump is rated at 255gph@3 bar, so for every bar pressure rise after that your pump will diminish its handling capabilities, you are going for 4 bar and thats already stressing the warlbro pump , so id suggest bypassing the warlbro and fitting a intank bosch 044, its pressure and flow rating that's usually advertised is at 5 bar, but it can handle more , but running it at your 4 bar is going to make it happy as a pig in shit

[savage1987]

that melted fuse mount is normal for commies of that age, heaps do it, getting a new fuse block fitted seems to work fine, but in a happy world yes new relays and wiring and fuses to your pump would be good, but in reality a new fuse block with fuse would suffice .
Failing your elec tests could be the problem but if voltage is good then test your pump again to be sure but it does look to be the pump as the problem so far

Ps the warlbro pump is rated at 255gph@3 bar, so for every bar pressure rise after that your pump will diminish its handling capabilities, you are going for 4 bar and thats already stressing the warlbro pump , so id suggest bypassing the warlbro and fitting a intank bosch 044, its pressure and flow rating that's usually advertised is at 5 bar, but it can handle more , but running it at your 4 bar is going to make it happy as a pig in shit
Sounds complicated. Tell me more.

I wasn't aware of the 3bar / 4bar thing with the Walbro. The pump does sound like it's struggling once the pressure builds up. Not at all the high pitched whine I was expecting.

Anyway 1 step at a time, I'll get a multimeter from someone and sus out the voltage feeding to the pump first of all.

[beefcake]

every pump has its advertised ratings as a sale point, the warlbro units are advertised as a massive 255lph unit but at 3 bar pressure,
And as with any elec pump it has a falling efficiency rate as pressure rises also versus voltage.
The bosch unit is rated at 5 bar and 200lph flow at 12v , but on the sliding scale if you back off the pressure the flow can rise but that's also related to fuel hose size and such but the usual efi hose size is sufficient for 99% of N/A applications , and also the fact that the pump will be running under its rated flow/pressure settings will make it work easier .
The warlbro though is being asked to work harder than its advertised ratings, hence its failure rate could possibly be higher , yet again in real life its not always true but the flow charts are a good indicator on how your chosen pump will go in your application

Edit : the 044 is rated at 15.5 amps max, so id sugest if you go that way you should run 20 amp cable and fuses and relays as a min then the warlbro pump at 60 psi has a amps rating of 9 so the warlbro aint a power monger like the old school bosch

[savage1987]

every pump has its advertised ratings as a sale point, the warlbro units are advertised as a massive 255lph unit but at 3 bar pressure,
And as with any elec pump it has a falling efficiency rate as pressure rises also versus voltage.
The bosch unit is rated at 5 bar and 200lph flow at 12v , but on the sliding scale if you back off the pressure the flow can rise but that's also related to fuel hose size and such but the usual efi hose size is sufficient for 99% of N/A applications , and also the fact that the pump will be running under its rated flow/pressure settings will make it work easier .
The warlbro though is being asked to work harder than its advertised ratings, hence its failure rate could possibly be higher , yet again in real life its not always true but the flow charts are a good indicator on how your chosen pump will go in your application

Edit : the 044 is rated at 15.5 amps max, so id sugest if you go that way you should run 20 amp cable and fuses and relays as a min then the warlbro pump at 60 psi has a amps rating of 9 so the warlbro aint a power monger like the old school bosch

I don't really understand how you are telling me to run this, from my understanding a 044 is an external pump.

I can't set up a surge unless they are engineerable in WA??? I would like to but have been told they are not allowed in road cars, not sure if believe.


Is there a bosch option for an factory in-tank pump replacement?



And WHY do so many people run these walbro pumps on LS1s in the US, they are in corvettes all over the place and to great effect :( i'm going to put it out there that i'm PRETTY confident they all run 58psi lol

[mitchy]

despite your whinge earlier....
you can run whatever psi you like through it, just the advertised flow is at a certain pressure.
up the pressure and you will drop the flow, and the life of the pump.

most aftermarket pumps flow figures are at 14v as well, wheres your stock wiring is likely to be 12v, and possibly even variable voltage with revs/load, etc.

a common setup is a bosch 040/044 with a relay off the factory wiring to get it to prime correctly/switch off when required, and a seperate feed from the battery to give it a full 14v. fuel is not something you want to fuck up.

[AGIT8D]

bosch 040 is the internal variant of the same specced 044 external i believe.

[savage1987]

despite your whinge earlier....
you can run whatever psi you like through it, just the advertised flow is at a certain pressure.
up the pressure and you will drop the flow, and the life of the pump.

most aftermarket pumps flow figures are at 14v as well, wheres your stock wiring is likely to be 12v, and possibly even variable voltage with revs/load, etc.

a common setup is a bosch 040/044 with a relay off the factory wiring to get it to prime correctly/switch off when required, and a seperate feed from the battery to give it a full 14v. fuel is not something you want to fuck up.
Thanks, good idea on the relay and bosch pump I think.. just wondering how it'll work in terms of physical setup inside the tank

bosch 040 is the internal variant of the same specced 044 external i believe.
I can't see the 040 being an easy fit into the in tank sender unit assembly though... ? is there a way to get around this without spending $50,000

[AGIT8D]

Thanks, good idea on the relay and bosch pump I think.. just wondering how it'll work in terms of physical setup inside the tank

I can't see the 040 being an easy fit into the in tank sender unit assembly though... ? is there a way to get around this without spending $50,000

Well, yes.. You can buy LSx powered cars for well under $50k now, some even with an aftermarket fuel system in place ;)

[stumps.]

I have an idea, and no offense but i think you should pay someone qualified to do this. Or at least offer someone here in the know some beer.

The last thing you want is
http://i132.photobucket.com/albums/q27/garvsVH/Motorvation%202010/Saturday/255.jpg

[savage1987]

hahahhahaaaha


yeah well I'll switch pumps and see if a freshie does the trick. Will use a fresh Walbro, see how we go

This chart seems to tell me it should be OK for a good while at 58psi at least

http://www.expressfuelpumps.com/images/GSS341chart.jpg

[Tre-Cool]

i reakon you'll get buy on leaving it at 50psi and just get the tune sorted to suit the lower pressure.

wont take much to do.

[Nemi]

i reakon you'll get buy on leaving it at 50psi and just get the tune sorted to suit the lower pressure.

wont take much to do.

yep thats about the level of intelligence we'd expect from you.
don't find out why you aren't getting the desired level of fuel pressure
don't fix it tune around the problem
and when the problem gets worse drops pressure and fucks the motor you'll have another mate who's as smart as you are.

[vy ss ute m6]

yep thats about the level of intelligence we'd expect from you.
don't find out why you aren't getting the desired level of fuel pressure
don't fix it tune around the problem
and when the problem gets worse drops pressure and fucks the motor you'll have another mate who's as smart as you are.

LOLLLLLLL Damo!!

[beefcake]

the 044 can be put intank no probs, nothing different about it. But as you mentioned its quite larger than a warlbro so its more of a nugget to fit.
Either way it looks like your on your way to trying a new one

[Tre-Cool]

yep thats about the level of intelligence we'd expect from you.
don't find out why you aren't getting the desired level of fuel pressure
don't fix it tune around the problem
and when the problem gets worse drops pressure and fucks the motor you'll have another mate who's as smart as you are.


Im not sure why you feel the need to try and finger bash me on the keyboard, but if you had ever spent any time working on ls1 motors and installing fuel systems for them, you would realise that just because the factory reg is set to 58psi in the tank doesnt mean it's going to have 58 psi in the rails.

I've seen on multiple cars with big dollar fuel systems to even the stock VX,VY - VE tanks that they will prime to a higher pressure than they idle/run at.

Sure, my post was a probably a bit short by saying get the tune adjusted, but this is still a custom setup, so he'd be silly not to have it checked anyway, he has allready stated in other threads & forums that he has had a few issuies with the engine (injectors) etc.

[joshg123]

hahahhahaaaha


yeah well I'll switch pumps and see if a freshie does the trick. Will use a fresh Walbro, see how we go

This chart seems to tell me it should be OK for a good while at 58psi at least

http://www.expressfuelpumps.com/images/GSS341chart.jpg

Forgive me for being condescending, but why dont you test the voltage at the pump and prove the point and have all information on hand. Once you are confident that your pump is fubar then change it out with a replacement/upgrade.

If your pump cant supply your desired fuel pressure (going off your post with the clamping reg line). Then its obviously the pump itself or its voltage source/earth return. Seems backwards to me to swap pumps and spend that time when 10mins with a voltmeter could save you *whatever time it takes you to change a pump*

Also if your pump can prime to pressure but cant sustain it after idling for a little while, perhaps check the size and condition of your earth's. Under no load the wire might have good continuity but a pump drawing big amps will heat that wire and its connections up and in this case fuel pressure will drop.

[savage1987]

Yep injectors were filthy as hell with 3.5yr old congealed fuel from sitting in an UN CAPPED rail for that time, lol

Tre-Cool, thanks, I know what you mean but I'll try to sort out the issue at the moment as there is something very wrong with this pump :p

[savage1987]

Forgive me for being condescending, but why dont you test the voltage at the pump and prove the point and have all information on hand. Once you are confident that your pump is fubar then change it out with a replacement/upgrade.

If your pump cant supply your desired fuel pressure (going off your post with the clamping reg line). Then its obviously the pump itself or its voltage source/earth return. Seems backwards to me to swap pumps and spend that time when 10mins with a voltmeter could save you *whatever time it takes you to change a pump*

Also if your pump can prime to pressure but cant sustain it after idling for a little while, perhaps check the size and condition of your earth's. Under no load the wire might have good continuity but a pump drawing big amps will heat that wire and its connections up and in this case fuel pressure will drop.
You're allowed to be "condescending", your info is helping me a lot lol

I will try multimeter job, will see if I can borrow one tomorrow and sus it out.

Re: earths, interesting and this seems to make sense from what I've seen on the gauge... again I'll check it out. Thanks!

[Nemi]

Im not sure why you feel the need to try and finger bash me on the keyboard, but if you had ever spent any time working on ls1 motors and installing fuel systems for them, you would realise that just because the factory reg is set to 58psi in the tank doesnt mean it's going to have 58 psi in the rails.

I've seen on multiple cars with big dollar fuel systems to even the stock VX,VY - VE tanks that they will prime to a higher pressure than they idle/run at.

Sure, my post was a probably a bit short by saying get the tune adjusted, but this is still a custom setup, so he'd be silly not to have it checked anyway, he has allready stated in other threads & forums that he has had a few issuies with the engine (injectors) etc.

working on or breaking (fucking) ? most people see these as 2 seperate things.

[Tre-Cool]

working on or breaking (fucking) ? most people see these as 2 seperate things.

lol who wouldnt.

You gave him advise, i gave him advise to get the tune looked at or adjusted if he cant get the fp up (but it's normal for it to drop from prime to running anyway).

I dont see why you have such a vendetta against me, it's not like im making money out of posting on here. It's also not the first time you've had a go at me so whats your problem?