Miata Turbo Forum - Boost cars, acquire cats. - 5PSI 10Degrees Stock GReddy + Jim Pipes

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5PSI 10Degrees Stock GReddy + Jim Pipes

5PSI, A/F was at 14:1 so aborted the run :)

what's with the dip? did your boost spike? got a log of the AFR? what are you using for fuel now? Stock pump?

Looks like how mine dropped off due to fuel issues.

mine did that before i had an o2 clamp

braineack, this was the dyno sheet from the discussion I was having with you on Saturday. Here's the A/F It's stock fuel stock vortech. can i run an o2 clamp w/o emanage?

Huh you're really fuel starved. Your stock pump really should do better. Do you have a fuel pressure gauge?

I see a walbro in your future.

Have you replaced your fuel filter?

You need to verify the condition of your pump. Looks like it can barely supply fuel. It could be working, the filter could be a restriction, or your plumbing could be wrong.

First off, verify your FMU is plumbed correctly. The fuel line from the OEM FPR should be connected to the offset fitting on the FMU. The center fitting shoulb be connected back into the return hardline. The line from the FEED line to the front of the fuel rail should not have been touched.

If this is correct then replace you fuel filter and buy a fuel pressure gauge and test your pump.

You'll need:

1 - Fuel Pressure Gauge (on the cheap at any local hydraulics store, try to get one that can read to at least 125psi)
1 - 5/16" brass tee
1 - 1/8" NPT to 5/16" fitting (for the gauge, shop shoudl be able to help)
5' - 5/16" fuel injection hose
5 - Screw clamps

To install:

Cut about 1' off the hose. Clamp that section to the brass tee. Clamp the 4' section to the tee as well. clamp the gauge on that 4' section.

Remove your fuel inlet hose from the hardline (otherside connects to the front of the fuel rail) and connect that to the tee. Then connect the 1' section of hose to the hard line.

To Test The Pump:

Start the car. Idle should be 35-36psi. Remove the vacuum line from the OEM FPR on the fuel rail. (Kink the vacuum hose so the car doesn't die). Idle should be 48-50psi.

Stop the car. Jump GND & F/P in the diagnostics box. Turn the car to ON, but don't start it. This will run the fuel pump. wrap cloth around the return line and use a vice grips or something similar and clamp down on the hose. This will increase the fuel in the rail. Verify 75-85psi.

If your pump cannot supply this amount then it may be in need of replacement.

To Test The FMU:

Ignition to ON. Keep the GND & F/P jumped. Run 5psi of air from an air compressor into your FMU vacuum line. Verify the fuel pressure increases to the max pump output.

hope this helps. can you send those .drf files this way?

^

You sir are truely helpful!

braineack is def. the man.

forgive my n00b question and the slight threadjack, but what's the ideal A/F? 13:1, 12:1?

right inbetween the two is the most potential for power/safety

Quote:

Originally Posted by Mach929 (Post 48144)

mine did that before i had an o2 clamp

what exactally does the o2 clamp do?

The clamp prevents "lean tip-in" by substituting the o2 sensor voltage output with another voltage, not allowing the ecu to cut fuel.

I've been searching on this site, the O2 clamp seems like a DIY project, are there any links?

get 50 posts and you could win one from older guyif you are the 50,000 post or just buy one from olderguy.:)

Braineack,

I'm thinking of doing the dual feed fuel rail and installing 1.8s while I'm at it. over on .net you said to use 21/64" Drill bit

1/8" NPT tap
1/8" to 5/6" brass ftting
5/6" Brass Tee
2 - 1' sections of 5/6" fuel injection line
JB Weld
Grease
5/6" Hose Clamps

is it 5/16 or 5/6?

http://forum.miata.net/vb/showthread...ight=feed+rail

5/16

5/6 would be HUGE :)