A couple EFI system Q's

[HighLife]

1. EFI filter after the surge tank but before high pressure pump or after the pump?

There is a lift pump in the fuel tank that has a sock on it - this fills the surge tank. I also have an inline 100 micron stainless mesh filter and am in two minds as to where to place it. A mate suggested before the pump to protect the fuel pump, but I dont really want to restrict the feed to the fuel pump from the surge tank and figure that the lift pump sock will catch anything that would kill the pump? After the pump the fuel is forced through the filter under pressure which I feel is a better solution?

2. I'm deleting the OEM fuel pressure reg(4AGE) and running an Malpassi rising rate reg. Do I use something like this "Sard Fuel Presssure Reg Adaptor"(bottom of page) to allow me to attach a fuel line to the fuel rail in place of the reg?

http://www.horsepowerinabox.com/hpiab2/category10_1.htm

[thechuckster]

1. EFI filter after the EFI pump. Keep lift-pump sock or put a very large low-pressure filter (e.g. something suitable for a hipo carbi V8) between tank and surge tank.

2. can you remote-mount the Sard? it's a lot of weight out on the end of an alloy adaptor that will break instead of bend when vigourously shaken or hit.

[HighLife]

2. can you remote-mount the Sard? it's a lot of weight out on the end of an alloy adaptor that will break instead of bend when vigourously shaken or hit.

Yep, its actually malpassi reg, I need to attach a fuel line barb or something to the fuel rail in place of the OEM reg, but there is no threaded hole, I'm looking for something to fit in place of the OEM reg and allow a barb fitting or something to be screwed in?

[thechuckster]

sorry - should have looked closer at link. Earls will probably have some kind of adaptor?

fwiw: my 3S rail came with a brass & speedflow fitting in place of the factory FPR. They'd cut a thread into the factory hole, fitting the brass fitting with some fuel-safe thread locker then the 90-degree speedflow fitting with a barbed section to suit EFI hose.

[HighLife]

sorry - should have looked closer at link. Earls will probably have some kind of adaptor?

fwiw: my 3S rail came with a brass & speedflow fitting in place of the factory FPR. They'd cut a thread into the factory hole, fitting the brass fitting with some fuel-safe thread locker then the 90-degree speedflow fitting with a barbed section to suit EFI hose.

Cool, yeah trying to avoid cutting a thread into the rail - from what I can tell those Sard adaptors look to be just a bolt in replacement for the oem reg with threaded boss so I can screw a 90 degree bard fitting or something into it.

[oldcorollas]

so there is no chance of running the stock FPR instead of the Malpassi?

[thechuckster]

See if you have a local performance shop that stocks Speedflow & earls fittings - the HIAB price for SARD fittings is a bit gold-plated?

Also - are you firm on the Malpassi regulator? My experience is that they're good for low-pressure high-volume boosted carbi setups but not ideal for EFI... but that's probably a topic for another thread.

[HighLife]

I have the Malpassi sitting here collecting dust from a previous project so figured I'd use it. The engine is turbo charged 4AGE in dedicated track car and I'm just setting up the fuel system with new 3/8 feed line, surge tank, bosch high pressure pump etc and figured I may as well use the malpassi to complete it and then I shouldnt have to worry about upgrading later?

I'm happy to listen to any arguments as to why I should stick with the OEM, I just figured the Malpassi would be better/more reliable/adjustable and seeing I already have it sitting here?

[benjamin]

http://cgi.ebay.com.au/Fuel-Pressure...3A1|240%3A1318

I bought one of these for my 4ag. Looks like it would work fine, just got to run a fuel line to the regulator.

Just one question, as this would increase the volume of the fuel rail is there any problems that arise, such as fuel pressure becoming not so well metered. I guess it would probably dampen the pulsing that occurs as the injectors open and slam shut...

[HighLife]

http://cgi.ebay.com.au/Fuel-Pressure...3A1|240%3A1318

I bought one of these for my 4ag. Looks like it would work fine, just got to run a fuel line to the regulator.

Yeah I looked at that too - basically what I was after but I'd prefer to have 90 degree bend coming out of the rail, so was after one with just a thread I could screw my own barbed fitting into.

Well after a bit of searching and some good advice I'm prob just gonna stick with the OEM reg. for the moment. The one I have already appears to be a manifold pressure referenced reg. so should do the job.

Just one question, as this would increase the volume of the fuel rail is there any problems that arise, such as fuel pressure becoming not so well metered. I guess it would probably dampen the pulsing that occurs as the injectors open and slam shut...

Just on a related note, I'm also plan on removing the stock pulsation damper and replacing it with barbed fitting to run my 3/8 hose straight into the fuel rail - will this cause any probs?

[oldcorollas]

the thing with fluids, is that they are crap at damping pulsations like a gas would be.

ie, unless your container is flexible, because fuel is fairly incompressible, removing or relaesing a very small volume can reduce pressure to zero.
having the damper, which acts as a flexible surface in the fuel line, reduces pulsation sand pressure drops by temporarily resupplying fuel to the rail..

think of it like an "accusump" for the fuel... while you don't need a damper, it is probably better to have one.

on my 7KE rail (and many others i think.. camrys and such), the damper has a long bolt bit, and goes through a banjo fitting into the rail... so the damper is effectively holding your fitting to the rail, no need for barbed fitting... ??

[HighLife]

Yeah that sounds like the 4AGE one. So if I kept it would I be able to get a replacement banjo fitting to suit the larger 3/8 fuel line or easier to just get a reducer in line before the rail?

[thechuckster]

my initial setup had no damper - and combined with a rising rate Malpassi, I had major fluctuations in line pressure and thus AFRs (making tuning a major headfuck).

I got a 2nd-hand Sard FPR and most of these issues went away. I eventually installed the pulsation dampener from a VL commodore (has external pump and dampener mounted near the tank) near the fuel rail.

re: banjo with barb fitting? see if yuor local Pirtek or Enzed shop can make you a fitting if they don't carry something as a stock item.

[HighLife]

re: banjo with barb fitting? see if yuor local Pirtek or Enzed shop can make you a fitting if they don't carry something as a stock item.

Cheers - took the banjo fitting into Enzed, he's welding a 3/8 barb in place of the stock 5/16 for next to nothing. So I have 3/8's feed all the way from pump to fuel rail, nice and neat and retaining the pulsation damper

Everythings sorted now, just got to bolt it all together with Loctite 567 on all the threads and hope for no leaks!