razorlab's simple build(s)
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
The fuel tank would have to be getting pressurized for that to happen, but if you are pulling fuel from the tank, it can't be getting pressurized, at least not for a correctly routed fuel line setup. If something were preventing the fuel pump from flowing, the fuel pump internal bypass would send fuel back into the tank, but that would not pressurize the tank. It would just create a small recirculating loop within the tank. My thought at this point is that there is some kind of routing error.
One question for you - Are you seeing 65-70 psi at the rail with the engine running or without it running. If its the latter, then those pressures are not unreasonable. The OEM fuel system sends full voltage to the pump during startup, and rail pressure is supposed to exceed the standard 3-bar value (for no vacuum at the intake manifold).
One question for you - Are you seeing 65-70 psi at the rail with the engine running or without it running. If its the latter, then those pressures are not unreasonable. The OEM fuel system sends full voltage to the pump during startup, and rail pressure is supposed to exceed the standard 3-bar value (for no vacuum at the intake manifold).
65-70 is it idling. If I get into any boost it hits 120+ (Only like 1-2psi boost since The motor only has 50 miles on it) which is obviously not right since 2 psi should only add 2 fuel pressure psi. The return line connection at the FPR actually slid all the way to the lip and the clamp stopped it. Thank god or I would have had a fun fuel explosion on the hwy!
As soon as i turn the motor off the rail pressure drops to 38.
The car was idling at 38-40psi and 60-65 at wot with the exact same setup last year before the motor went.
The surge outlet was 20psi, now it's 60psi.
The last thing I haven't checked yet is the JEGS SS fuel filter on the feed line. I will crack that open sometime this week.
Last edited by razorlab; Jul 30, 2017 at 07:38 PM.
EvoM Guru
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From: Tri-Cities, WA // Portland, OR
I suppose there is one way fuel could be ejected from the return line if everything was correctly routed - That would be if circulating the fuel in the fuel tank caused some vaporization that raised the fuel tank pressure. This would be relatively temporary though, and it should flow much less than if it were being pressurized by a fuel pump.
If the fuel pressure at idle is 65-70 psi, then its a certainty that the fuel pump is seeing full voltage or something higher than the standard low voltage value of ~10 volts. In the standard low voltage mode, the pump would stall before reaching 65-70 psi.
If the fuel pressure at idle is 65-70 psi, then its a certainty that the fuel pump is seeing full voltage or something higher than the standard low voltage value of ~10 volts. In the standard low voltage mode, the pump would stall before reaching 65-70 psi.
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
well, apparently my cam phaser solenoids DO work, or, they where working.
Take a look at this log. This was after driving around town for about 15mins. This is a new log I started after that. The logs before showed actual and commanded mivec 100% aligned, aka working 100%.
Now, in this log you can see where they where doing just that and then actual on both cams just flatlined and stayed there. I marked in the log where it happens. I also have another log after this from cruising on the hwy where actual is flatlined the whole time (about 20 mins of driving)
http://datazap.me/u/razorlab/mivec?l...6-27&mark=2858
So either the car is losing oil pressure when hot (fffffuuuu!!) or both my solenoids crapped out at the same time (highly unlikely).
I'll get another log while the car is cool to see if it is heat related.
btw, currently using dino 10w40 while the engine breaks in
Take a look at this log. This was after driving around town for about 15mins. This is a new log I started after that. The logs before showed actual and commanded mivec 100% aligned, aka working 100%.
Now, in this log you can see where they where doing just that and then actual on both cams just flatlined and stayed there. I marked in the log where it happens. I also have another log after this from cruising on the hwy where actual is flatlined the whole time (about 20 mins of driving)
http://datazap.me/u/razorlab/mivec?l...6-27&mark=2858
So either the car is losing oil pressure when hot (fffffuuuu!!) or both my solenoids crapped out at the same time (highly unlikely).
I'll get another log while the car is cool to see if it is heat related.
btw, currently using dino 10w40 while the engine breaks in
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
Is your FPR on the rail, or on the surge tank?
I think whats happening is your lift pump is pressurizing the surge tank, and forcing fuel up the return line to the rail. Try drilling your siphon to 7/64" or 9/64".
I think whats happening is your lift pump is pressurizing the surge tank, and forcing fuel up the return line to the rail. Try drilling your siphon to 7/64" or 9/64".
Are your afr's normal with this high pressure? Does it stumble during idle and is smooth during accel? I would equate pig rich afr's and a crappy running motor with high fuel pressure.
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
Again, the pressure is the same with the surge tank in use or bypassed so it's not the surge tank doing this.
Also, everything was just fine with the same setup last year before my motor went.
I can't put too much load on the car as the engine only has 50 miles.
Thread Starter
Joined: Aug 2003
Posts: 14,094
Likes: 1,092
From: Mid-Hudson, NY
It's for sure running super high pressure, the hose off the FPR keeps backing off. The clamp is the only thing keeping it on right now.
Not sure but I just bought a used one off ebay to swap and see.
Not sure but I just bought a used one off ebay to swap and see.