P0087 Low Fuel rail pressure

[GT86meMR2]

Hey i have a problem.. My car occasionaly has a P0087 cel while idling 99% at a cold start.. Idle is Little rough when It happens and if cel hits throttle Will NOT respond until i restart the car

CAR drives fine for the rest NO power loss or any problems while driving.. And the cell wil dissapear after soms driving.

Fuel rail pressure seems to drop occasionally when It happens but returns To normaal when i restart the car.. I have the latest OFT uel map and while logging the car nothing is out of the ordinary..

Question can a aftermarket header in any way Be responsible for over Time failure of fuel pressure?

Ps:sry If My English is hard To Read.written by smartphone.

[zkv476]

Low fuel rail pressure applies only to direct injection, there is a solenoid I believe that can control fuel pressure. At idle the commanded fuel pressure is around 4 MPa or ~580 psi. If you are getting this issue there may be something wrong with your high pressure fuel pump or the solenoid built into it (they are one piece) that is preventing it from maintaining the pressure while the RPM is relatively low. Headers are probably not the reason for this issue.

[GT86meMR2]

Originally Posted by zkv476

Low fuel rail pressure applies only to direct injection, there is a solenoid I believe that can control fuel pressure. At idle the commanded fuel pressure is around 4 MPa or ~580 psi. If you are getting this issue there may be something wrong with your high pressure fuel pump or the solenoid built into it (they are one piece) that is preventing it from maintaining the pressure while the RPM is relatively low. Headers are probably not the reason for this issue.

Thank You! Fuel pressure is 4mpa At idle but Will occasionally drop To around 2mpa restarting brings It back To 4.. Dealership is Just giving me a hard Time because i have the header and says they will probably denied warranty because of it as the problem would probably Be linked To the header.. Without even knowing what the actual problem is..

[YMAA]

Had a similar issue with my car about a year ago and the cause turned out to be bad quality gas (the pump said 93, so I dunno). When I switched to another brand the problem went away after a few days.

[GT86meMR2]

Originally Posted by YMAA

Had a similar issue with my car about a year ago and the cause turned out to be bad quality gas (the pump said 93, so I dunno). When I switched to another brand the problem went away after a few days.

Did It give the same cel code p0087 in Your case?

[YMAA]

No, my codes were P0193 and P0191. But those have to do with the fuel rail pressure sensor as well.

[GT86meMR2]

Question: How come my car only has problems holding pressure at Idle nut has NO problems under heavy load high rpm without power löss?

[aagun]

check ur fuel regulator

[GT86meMR2]

Well as long that i don't let It idle when cold the cell Will stay away it seems.

[GT86meMR2]

Well warranty was denied because according To them My full exhaust produced higher co2 and because of that It was NOT conform anymore with the fluids in the CAR... Whatever that had To do with occasional drop of fuel pressure NOT a clue.. :p the shit part is now im still NOT 100% Sure what the probleem is.

[zkv476]

Unfortunately it sounds like the dealer is serving you a load of crap. Not conforming with fluids in the car because of a header, huh? If there is a mechanical problem, it'd be in the high pressure fuel pump assembly, which consists of the pump and solenoid in one unit. My theory is that at low RPM the solenoid has issues controlling the pressure causing it to code out or the pump is starting to go out.

[GT86meMR2]

Originally Posted by zkv476

Unfortunately it sounds like the dealer is serving you a load of crap. Not conforming with fluids in the car because of a header, huh? If there is a mechanical problem, it'd be in the high pressure fuel pump assembly, which consists of the pump and solenoid in one unit. My theory is that at low RPM the solenoid has issues controlling the pressure causing it to code out or the pump is starting to go out.

So in your opinion would replacing the high pressure fuel pump fix the problem or is it the regulator? And yeah they were definetly full of shit.. I don't even want to try anything trough the dealer anymore Just want to know for Sure what needs replacing.

http://m.benl.ebay.be/itm/2013-Subar...695?nav=SEARCH (Just as example)

[zkv476]

I couldn't say for sure. Which regulator do you mean? There is a low pressure 58 psi regulator in the tank. The solenoid controls high pressure fuel pressure and is a single unit with the high pressure pump mounted on the LH head.

I can't say for sure if it's the problem or not, I've never heard of this issue before, but it's what I'd imagine is the problem and not prohibitively expensive so it's worth a shot I'd say.

[GT86meMR2]

Originally Posted by zkv476

I couldn't say for sure. Which regulator do you mean? There is a low pressure 58 psi regulator in the tank. The solenoid controls high pressure fuel pressure and is a single unit with the high pressure pump mounted on the LH head.

I can't say for sure if it's the problem or not, I've never heard of this issue before, but it's what I'd imagine is the problem and not prohibitively expensive so it's worth a shot I'd say.

Is the eBay link the correct high pressure fuel pump assembly? And well im not Sure they Always told me "The Fuel pressure regulator" thanks for helping though.