Strange fuel pressure issue E85
03-20-14, 12:39 AM
#26
Yes in three different sections of the car it failed in the front so I replaced the fuel lines thinking it was a kinked Teflon line. I didn't flow test only did a log after the lines were replaced and no change. So I jumped to removing the inline filter thinking that might be it.
03-20-14, 10:16 PM
#29
35r 13b first gen
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Is what u read for piston Hp or rotary Hp? If I'm not mistaken a piston engine will use roughly 30% less fuel than a rotary to make the same power... If I'm not mistaken
03-21-14, 03:58 PM
#32
Maybe I'm on to something my fuel lines run off a Fuel Y block to the fuel rails out of the fuel rails they tie into the FPR independently.
What if my primary fuel line is robbing the secondary fuel line of pressure is this possible? Meaning instead of getting 50/50 it's getting 60/40. The only way to check would be to have a T at the end of the fuel rails, run it like stock setup or have two fpr's.
Thx again for all your help
-J
What if my primary fuel line is robbing the secondary fuel line of pressure is this possible? Meaning instead of getting 50/50 it's getting 60/40. The only way to check would be to have a T at the end of the fuel rails, run it like stock setup or have two fpr's.
Thx again for all your help
-J
03-22-14, 07:45 AM
#33
Racing Rotary Since 1983
iTrader: (6)
a very interesting thread as you have covered most of the fixes but aren't there yet...
i assume you are running E85, what premix are you running and how much per gallon?
have your run your car on gasoline?
while i understand you have tried your sensor at the FPR i do recommend you permanently use the FPR for your sensor.
it may be you have two problems. the erratic fuel pressure and the decay of pressure under boost.
how is your idle vacuum? perhaps all is working correctly as to the vacuum signal and the vacuum is varying.
i would re-visit the FPR. if there is any minescule leak in the diaphragm of the ball/seat you would get your symptoms.
FWIW, when i converted to E85 i replaced the OE steel feed line w -8 to the motor and retained the OE return line. i use dash 6 at the engine w a Y block and take the signal off the FPR. i have constant pressure at 575 and 25 psi. (Walbro 9000267 pump).
i do suggest you look very carefully at your signal line to the FPR.
i also suggest you swap out your AEM pressure sensor for the real deal which is Honeywell.
short of that i would datalog the voltage to the sensor.
i realise you have done most of this but thought i would enter the thread. i appreciate your current frustration and expect it will be sweet and instructive when you solve the problem.
as well as helpful to the rest of us.
good luck,
howard
i assume you are running E85, what premix are you running and how much per gallon?
have your run your car on gasoline?
while i understand you have tried your sensor at the FPR i do recommend you permanently use the FPR for your sensor.
it may be you have two problems. the erratic fuel pressure and the decay of pressure under boost.
how is your idle vacuum? perhaps all is working correctly as to the vacuum signal and the vacuum is varying.
i would re-visit the FPR. if there is any minescule leak in the diaphragm of the ball/seat you would get your symptoms.
FWIW, when i converted to E85 i replaced the OE steel feed line w -8 to the motor and retained the OE return line. i use dash 6 at the engine w a Y block and take the signal off the FPR. i have constant pressure at 575 and 25 psi. (Walbro 9000267 pump).
i do suggest you look very carefully at your signal line to the FPR.
i also suggest you swap out your AEM pressure sensor for the real deal which is Honeywell.
short of that i would datalog the voltage to the sensor.
i realise you have done most of this but thought i would enter the thread. i appreciate your current frustration and expect it will be sweet and instructive when you solve the problem.
as well as helpful to the rest of us.
good luck,
howard
Last edited by Howard Coleman; 03-22-14 at 09:01 AM.
03-22-14, 08:16 AM
#34
Racing Rotary Since 1983
iTrader: (6)
i suggest you purchase a laboratory grade 4 inch dial zero to 30 psi liquid filled pressure gauge and an adj pressure regulator. hook them up to the incoming line to your FPR...
datalog various pressure levels at your regulator and see if they cross check with the gauge as well as if they maintain pressure. you can do this at other locations in your set up as well.
i use this rig for lots of valuable jobs such as checking the MAP sensor and calibrations...
HC
datalog various pressure levels at your regulator and see if they cross check with the gauge as well as if they maintain pressure. you can do this at other locations in your set up as well.
i use this rig for lots of valuable jobs such as checking the MAP sensor and calibrations...
HC
Last edited by Howard Coleman; 03-22-14 at 09:02 AM.
03-22-14, 08:46 AM
#35
to stand out of the crowd if you will. We would all be driving gt40 Ferrari's if we could afford it.
We expect to have Supercar performance( Hypercar performance for the hardcore dudes) on a shoe string budget.
However, in order to achieve this performance, we must stray from the conventional, and go so far as to re-engineer our vehicles.
When we get so far off the reservation, and get so deeply lost in the woods we cannot find our way back by ourselves,
that is when we can rely on our rotary buddies here.
I think this thread is a great example. The fact that nobody has suggested that the OP use the search feature to solve his issue,
and everyone has offered some very valuable troubleshooting advice. We have come together to help our fellow rotor head in need.
In conclusion, Howard is exactly right when he says "expect it will be sweet and instructive when you solve the problem."
(Sorry for the creative writing. Coffee and passion get the better of me sometimes.)
PISTONS, you may be on to something with the FPR.
This is just theory; but I've been doing some research on noise canceling headphones.
This gave me the idea that you may have opposite pulses inside the FPR. if this is the case you would be essentially canceling the other pulses out.
Something like ANR Headphones do.
Just a thought,
Joe
03-22-14, 09:45 AM
#36
a very interesting thread as you have covered most of the fixes but aren't there yet... I've taken my car to a couple shops and they've had no luck because as you said we've done most of the fixes and nothing has fixed it.
I assume you are running E85, what premix are you running and how much per gallon? Yes E85 With Klotz Benzol 1 ounce per gallon
have your run your car on gasoline? No only E85 on fuel I'm sure I would have no issue at 14 psi 91 octane.
while i understand you have tried your sensor at the FPR I do recommend you permanently use the FPR for your sensor.
it may be you have two problems. the erratic fuel pressure and the decay of pressure under boost. Yes erratic I believe because of sensor location but the decay of fuel pressure gets me.
how is your idle vacuum? perhaps all is working correctly as to the vacuum signal and the vacuum is varying. It was good but I will double check
i would re-visit the FPR. if there is any minescule leak in the diaphragm of the ball/seat you would get your symptoms. I thought the same thing since I anodized the FPR and rebuilt it myself so I changed it for a Brand new FPR no change.
FWIW, when i converted to E85 i replaced the OE steel lines w -8 to the motor and retained the OE return lines. i use dash 6 at the engine w a Y block and take the signal off the FPR. i have constant pressure at 575 and 25 psi. (Walbro 9000267 pump). As you know -6 through my whole fuel system and when I take the signal off it does the same thing.
I do suggest you look very carefully at your signal line to the FPR. I will triple check it but I've pulled it off set a base 60 psi and it dropped pressure.
I also suggest you swap out your AEM pressure sensor for the real deal which is Honeywell.
short of that i would data log the voltage to the sensor. I've changed the sensor since I read a couple guys had a fuel pressure issue with the FPS being the problem. I've also watched the liquid filled gauge do the same pattern.
I realize you have done most of this but thought i would enter the thread. i appreciate your current frustration and expect it will be sweet and instructive when you solve the problem.
As always I appreciate any help or knowledge you guys can send my way it keeps me going on this issue. I will make sure when I do find the problem the fix and data will be posted
as well as helpful to the rest of us.
good luck,
howard
I assume you are running E85, what premix are you running and how much per gallon? Yes E85 With Klotz Benzol 1 ounce per gallon
have your run your car on gasoline? No only E85 on fuel I'm sure I would have no issue at 14 psi 91 octane.
while i understand you have tried your sensor at the FPR I do recommend you permanently use the FPR for your sensor.
it may be you have two problems. the erratic fuel pressure and the decay of pressure under boost. Yes erratic I believe because of sensor location but the decay of fuel pressure gets me.
how is your idle vacuum? perhaps all is working correctly as to the vacuum signal and the vacuum is varying. It was good but I will double check
i would re-visit the FPR. if there is any minescule leak in the diaphragm of the ball/seat you would get your symptoms. I thought the same thing since I anodized the FPR and rebuilt it myself so I changed it for a Brand new FPR no change.
FWIW, when i converted to E85 i replaced the OE steel lines w -8 to the motor and retained the OE return lines. i use dash 6 at the engine w a Y block and take the signal off the FPR. i have constant pressure at 575 and 25 psi. (Walbro 9000267 pump). As you know -6 through my whole fuel system and when I take the signal off it does the same thing.
I do suggest you look very carefully at your signal line to the FPR. I will triple check it but I've pulled it off set a base 60 psi and it dropped pressure.
I also suggest you swap out your AEM pressure sensor for the real deal which is Honeywell.
short of that i would data log the voltage to the sensor. I've changed the sensor since I read a couple guys had a fuel pressure issue with the FPS being the problem. I've also watched the liquid filled gauge do the same pattern.
I realize you have done most of this but thought i would enter the thread. i appreciate your current frustration and expect it will be sweet and instructive when you solve the problem.
As always I appreciate any help or knowledge you guys can send my way it keeps me going on this issue. I will make sure when I do find the problem the fix and data will be posted
as well as helpful to the rest of us.
good luck,
howard
I've answered the questions in the quote
03-22-14, 09:51 AM
#37
i suggest you purchase a laboratory grade 4 inch dial zero to 30 psi liquid filled pressure gauge and an adj pressure regulator. hook them up to the incoming line to your FPR...
datalog various pressure levels at your regulator and see if they cross check with the gauge as well as if they maintain pressure. you can do this at other locations in your set up as well.
i use this rig for lots of valuable jobs such as checking the MAP sensor and calibrations...
HC
datalog various pressure levels at your regulator and see if they cross check with the gauge as well as if they maintain pressure. you can do this at other locations in your set up as well.
i use this rig for lots of valuable jobs such as checking the MAP sensor and calibrations...
HC
Here is a great inline fuel filter 10 micron SS with an option for a gauge:
F-10 Inline Modular Fuel Filter
03-22-14, 09:58 AM
#38
Wow, what a true quote. As rotary enthusiasts, we are essentially people who demand a higher level of performance,
to stand out of the crowd if you will. We would all be driving gt40 Ferrari's if we could afford it.
We expect to have Supercar performance( Hypercar performance for the hardcore dudes) on a shoe string budget.
However, in order to achieve this performance, we must stray from the conventional, and go so far as to re-engineer our vehicles.
When we get so far off the reservation, and get so deeply lost in the woods we cannot find our way back by ourselves,
that is when we can rely on our rotary buddies here.
I think this thread is a great example. The fact that nobody has suggested that the OP use the search feature to solve his issue,
and everyone has offered some very valuable troubleshooting advice. We have come together to help our fellow rotor head in need.
In conclusion, Howard is exactly right when he says "expect it will be sweet and instructive when you solve the problem."
(Sorry for the creative writing. Coffee and passion get the better of me sometimes.)
PISTONS, you may be on to something with the FPR.
This is just theory; but I've been doing some research on noise canceling headphones.
This gave me the idea that you may have opposite pulses inside the FPR. if this is the case you would be essentially canceling the other pulses out.
Something like ANR Headphones do.
Just a thought,
Joe
to stand out of the crowd if you will. We would all be driving gt40 Ferrari's if we could afford it.
We expect to have Supercar performance( Hypercar performance for the hardcore dudes) on a shoe string budget.
However, in order to achieve this performance, we must stray from the conventional, and go so far as to re-engineer our vehicles.
When we get so far off the reservation, and get so deeply lost in the woods we cannot find our way back by ourselves,
that is when we can rely on our rotary buddies here.
I think this thread is a great example. The fact that nobody has suggested that the OP use the search feature to solve his issue,
and everyone has offered some very valuable troubleshooting advice. We have come together to help our fellow rotor head in need.
In conclusion, Howard is exactly right when he says "expect it will be sweet and instructive when you solve the problem."
(Sorry for the creative writing. Coffee and passion get the better of me sometimes.)
PISTONS, you may be on to something with the FPR.
This is just theory; but I've been doing some research on noise canceling headphones.
This gave me the idea that you may have opposite pulses inside the FPR. if this is the case you would be essentially canceling the other pulses out.
Something like ANR Headphones do.
Just a thought,
Joe
03-22-14, 12:23 PM
#41
Racing Rotary Since 1983
iTrader: (6)
" fuel transitions from primary to secondary under specific load now does the fuel in the primary drop off or they remain at full flow working with the secondary's under full load?"
the pressure in both rails should remain virtually identical.
usage depends on how your ECU works. the Power FC throttles back the primaries after crossover a bit.
the pressure in both rails should remain virtually identical.
usage depends on how your ECU works. the Power FC throttles back the primaries after crossover a bit.
03-25-14, 11:37 AM
#48
have you also monitored the voltage to the pump while the drop is occurring? though the ECU isn't seeing a drop it could be that your relays are straining under the amperage and heat. if you're running a single 30a relay then you should split it into 2 relays to half the load through each.
03-25-14, 04:38 PM
#49
have you also monitored the voltage to the pump while the drop is occurring? though the ECU isn't seeing a drop it could be that your relays are straining under the amperage and heat. if you're running a single 30a relay then you should split it into 2 relays to half the load through each.
Yes I've monitored the voltage on the computer and at the relay both read slightly over 13.0 volts on load.
I will check the relays to see if they are getting hot and report back.
