Bri Bro

Why would a FPR run hot? It is a diaphragm that opens and closes to control fuel pressure and it always has lot of cold fuel flowing through it. I have adjusted mine at the track a couple of times and I never felt any heat come from it...easy to touch. Where is it mounted?

Getting hot doesn't sound right to me.

Techno Duck

Tom, to answer your question.. i have no idea! I am out of ideas and this is all i can think of. My best guess is at a certain engine fuel requirement, fuel pressure, vacuum, whatever.. basically when all conditions are right something in the FPR is not functioning right. Maybe the diaphragm or spring.. i really dont know. I am honestly out of ideas at this point so i figure i just keep ruling things out.

Brian, regulator is mounted on the cruise control bracket.. so in close proximity to the headers.

A buddy of mine with a WRX mentioned he had similar problem right after installing the same model Aeromotive FPR on his car. He said to me he never could figure it out what was causing it and has since tuned it out. He is very mechanically inclined and i trust his judgement. His regulator is mounted not far from his downpipe.. so this made me think a bit harder about the FPR thing.

Stephencs601

Jon,

Good luck at sea. Call me when you get back

Bri Bro

That is were I have mine mounted and it didn't feel hot both time I adjusted it at the track and when I first set it up. I didn't go out of my way to check that but I will when I get the new engine fired up. I will put a temp sensor on mine the next time I run it.

Have a good rotation!!

Techno Duck

Some pics of how i get it mounted. It gets uber hot when sitting after driving, as long as the car is moving it stays at a relatively reasonable temp though.





Another thing Tom brought up is pressure testing the boost controller / wastegate loop. Ive never done it because usually i pressure test from the intercooler inlet coupler. Never really saw the need as all the lines are relatively new but will check everything when i get home.

Not looking forward to this rotation.. just got on today and already have to swap out two aftercoolers and 2 cylinder heads on one of the main engines. This is why i have little to no desire to work on my car when i get home!

Ronin-951

Dont know if there's any voids in your aftermarket fuel regulator, is it possible there's Air trapped inside? Speaks to the Hot hardware also.

Techno Duck

Finally back home, thankfully i didnt think about this much when i was away!

So tomorrow i will either be happy or pissed when i hook up my stock fuel rail and rule out the Aeromotive FPR. I am too lazy to take out the fender liner to hook up the stock lines at the hardlines.. so figured why not just hook up my original fuel lines to the AN lines running off the hardlines! Just needed to cut off the old fittings and picked up a -4 and -6 Push-Lok from Jegs. Then using a -6 to -4, and a -8 to -6 reducer i can hook up the original rail. Its an unnecessary amount of fittings to be using i know.. but this will literally be on the car for about 10 miles while i test it out.



If the FPR is not the problem, the last thing i can think to get rid of the lean spot is install this..

Stephencs601

no, Jon, do not install that everyone has motor. When you drive, the heat from the headers is pushed right up to the FPR. Air movement may be what heats it up. Move the FPR and see if that helps. Aslo, do not forget about 8/26 GTG

Techno Duck

Well now for some good news finally. I put the stock rail / 3-bar regulator back on this morning. Have put about 30 miles on the car, with plenty of stopping inbetween to let it heat soak. Problem has not happened once! I am going to do some more driving on it tomorrow to be sure but i am fairly certain the problem is the Aeromotive FPR. I contacted them about exchanging mine.. though not sure how long it will take. I can get another Aeromotive regulator locally for about $180 tomorrow which i am tempted to do.. though i hate to end up with another damn regulator...and still i am not 100% convinced the problem is fixed yet.. id say like 90% convinced .

For test purposes only.. .

Bri Bro

You need to take up plumbing for a living. .

Glad to hear the test was positive, this was a strange problem

Tom M'Guinn

That's great -- good luck with your testing tomorrow! Those are some crazy fuel lines If the FPR does turn out to be the problem (fingers crossed) then you might want to move it. It's sort of sitting over the headers like a marshmallow at a campfire....

MM951

Beautiful upper. What handguard is that?

Oh, and good to hear that you are working towards a solution with the 951

Thom

Good to hear you seem to have found the problem

Why still bother with an aftermarket fuel rail and FPR if the stock ones work fine?

Techno Duck

Put some more mileage on this morning and still no lean spot. So i am pretty convinced at this point the fuel pressure regulator is the problem. I am going to wait until monday to see what i can work out with Aeromotive about getting a repair / exchange done. Its going to rain the next few days anyhow so wont be driving it. Until then i am going to leave the stock rail on the car.

Thom, i am not to keen on continuing to run the stock fuel rail. I actually sold my spare to a friend a few months ago because his cracked. That would make the 2nd person i know who had this problem. Plus Dave's fuel rail looks damn good ... its like the only piece of shiny bling under the hood of my car .

Just want to say thanks to Brian who loaned me those ECU's, Steve who loaned me a set of injectors and everyone else who kept PM'ing me with more ideas to try.

Mike, its a BCM upper with a Daniel Defense 12" handguard. I posted some complete pictures of the build in the random picture thread in the firearms forum. Cant wait to bring it to the range next week!

fast951

Glad you found the problem. I would hate to imagine spending all those hours diagnosing the potential causes and not find a the problem.