HELP: SARD FPR install problems
 

I just installed a SARD FPR today and im having fuel pressure problems.

I set base pressure with the vac line off at 39psi as per OEM specifications

Problem is that when I hit boost the fuel pressure doesnt increase with boost pressure enough.

Im set for 16psi of boost. But Fuel pressure is only going up to 43psi at max boost. Only 4psi over base pressure. It should be up to at least 55psi.

I did re-connect the vac line and I cant see any leaks.

Does it matter where I plumb in the guage to check pressure? I have it T-eed in on the fuel line right after the fuel filter

Whats going on? Faulty FPR?

Something else I noticed too is that the fuel pressure when priming is slow to build compared to the OEM FPR making for a rough start, and that after I switch off the engine, the fuel pressure almost immediately drops to 9psi. With the OEM FPR, It used to hold pressure after switching off for a fair while.

Sounds like its a shizen FPR.

Knowing you, you have a fresh filter in it etc. What pump?

sure u plumbed it correctly?

Iv got one and it acts normally. I have the gauge plumbed into the FPR itself.

If it is a dodgy unit - i'l sell u mine as I got something else coming :D

Yep. Fresh Fuel Filter

Ive got it plumbed with the fuel line from the rails going into the top port and coming out the bottom going to the fuel tank return.

Tomorrow Im going to run an OEM FPR in the SARD's location. If my problem goes away, it will confirm the dead SARD FPR.

I have also checked for leaks. I clamped the return line to push the pressure up over 60psi and checked all the new fittings and no problems.

i wouldnt recommend an aftermarket fpr unless you were running over 90% duty and had a massive fuel pump.

I opted for a aftermarket FPR simply because my OEM FPR was failing. It was doing something similar to what the SARD is doing now but not on such a large scale. It was still rising fuel pressure 10psi. But still not enough to match boost increases.

Plus I am running over 90% duty. I do have a Walbro fuel pump installed, but its not massive of course.

tiny injectors or lots of boost?

tiny injectors (380cc) and 16psi through a vf28. Not exactly lots of boost, but enough to max out tiny injectors.

i'd check the pump delivery, somethings not adding up!

stock fpr is more then adequate for that!

checked the pump. Pump is running fine.

You are right. Stock FPR is more than adequate. But my stock FPR became faulty. Not rising enough fuel pressure on boost causing it to lean out and knock which then caused the ECU to pull timing. Which is why I originally bought the SARD FPR. However, the SARD is now doing the same thing, but even worse.

I got my hands on another OEM FPR which I am going to try today. But after already purchasing the SARD FPR to replace my original faulty FPR, I may as well put it or the warranty replacement SARD FPR to good use once I confirm whether or not it is faulty.

WHS ^^

Possible fake Walbro? Google it.....

static pressure o.k. but poor flow?

Check the voltage at the pump when running, voltage drop will cause slow priming.

Is there one on the manifold to try?

[QUOTE=Mister Two;381528]checked the pump. Pump is running fine.



You are right. Stock FPR is more than adequate. But my stock FPR became faulty. Not rising enough fuel pressure on boost causing it to lean out and knock which then caused the ECU to pull timing. Which is why I originally bought the SARD FPR. However, the SARD is now doing the same thing, but even worse.
[/QUOTE]

This is pointing to a pump flow issue bud....... 2 x rooted FPR's? not likely.

Static pressure maybe fine as there is minimal volume being pumped static, but once the injectors starts using lots of fuel the pump can't keep up.

Have you tried running it under load with the return clamped to see if the fuel pressure drops away as injector duty cycle increases?

hmm I think i have or at least had a similar issue
mine got alot better after mounting the sard differently, but because i havent been running anything over 14pound for ages i dont know if it's fixed itself..

where'd you buy your walbro?

I got my Walbro off a rexnet vendor.

I am able to manually adjust the fuel pressure on the SARD to whatever level I want. If I set the base pressure to 50psi then the fuel pressure will ensure I dont knock on boost. but it will be quite rich everywhere else.

Getting base pressure is not a problem. Its the rising rate component of the FPR that seems to have problems.

got a leak in your vacuum line to FPR?

Its a new vacuum line. I checked it for nicks or cuts and it seems clean. When I take the vacuum line off I can feel the suction of the engine.

If you set it to 50 psi with the vacuum line off will it hold 50 psi with the engine under load/ on boost?

Just clarifying.......

yes, it will hold 50psi and under boost will rise fuel pressure, but only rise by 4psi when it should be rising by 16psi.

With the vacuum line [B]disconnected.[/B]
[B]Drive [/B]the car on boost whatever base pressure you set (set it high to be safe) does the pressure stay constant?
Or does the pressure drop?

Pressure will not rise with the line disconnected.

If the pressure drops with high injector duty cycle you have a pump volume issue.

I did some more testing.

Set the SARD on 50psi base pressure and went for a drive with the vac line off. No fluctuations of fuel pressure on boost. Confirmed the fuel pump is 100% operational

Installed a Gen 2 Legacy TT OEM FPR with a base pressure of 48psi that I got off Teejay. Set boost for 14psi. Hit 62psi fuel pressure at 14psi of boost. That is correct operation for a 1:1 rising rate FPR. Although the TT FPR base pressure is quite high, its still operating correctly. Also, as soon as engine is turned off, fuel pressure is maintained in the lines

Confirmed the SARD is faulty. Sending it back for replacement.

Well I got my new replacement SARD FPR.

Still got problems. Going up to 16psi of boost, fuel pressure only rises by 8psi.

Its better than before but still not good enough. Im sick of this already. Im just gonna try to get a refund and try a different brand altogether. Or just use a OEM FPR from a GD which as a 43psi base pressure.

OEM reg and a squeeze up in the vice.;) Set whatever pressure you want.

^^ WHS - I've used the squeeze and test method on my 13b turbo's a few times in the past......It's how the manufacturer sets all the reg's the same at the point of manufacture.

I thought Sard was a 'good' brand? Are you sure they're not chinese sard rip-offs?

There was an issue with Chinese rip-off Malpassi rising rate regs years ago.

Mine is definitely genuine SARD.

fuel pump.

Its not a fuel pump issue Stace. Its a 2 year old Walbro 342.
It holds 50psi base fuel pressure with the vac line off on full boost.
And it operates properly when a OEM FPR is used. The TT OEM FPR has a high base fuel pressure but rises the fuel pressure properly in accordance with boost.

problems with 3 different fprs, including the stock one.
my money is on the pump still :)

Borrow a pump to try?

15 minute job.... V's banging head against wall?

remembering that your line pressure must be 43psi + manifold pressure.

so at 1bar of boost, you need to have around 60psi of rail pressure.

50 psi is too low.

[QUOTE=tuna;383401]problems with 3 different fprs, including the stock one.
my money is on the pump still :)[/QUOTE]

Or Pump relay or the connector on to the tank cover.....you can have good voltage but no amperage.

Alright. I'll do another test at 60psi and see how that goes. I'll check the connectors and if need be, Ive got a spare pump from a Bugeye WRX I can try.

resolved?

I did another test at 60psi with the vacuum hose off and got no reduction of fuel pressure on boost. Its pretty safe to say the fuel pump is ok.

Interestingly when I connected a OEM GD FPR. Base pressure was 55psi! Tested it with 2 different guages. One mechanical guage and one electrical guage. These OEM FPRs are not infallible. My Original Legacy one died. 1 dead SARD and another probably dead SARD (Still testing).

Maybe im just shit out of luck? Third time's the charm

Sorry to bring up such an old topic, but did you ever get to the bottom of your problem? i happen to be having the same issues at the moment...