bubbling sound

[turbonola]

ok so i've got a bubbling sound coming from my fpr now. it happened after i relocated my battery to the trunk. before i relocated the battery it wasn't doing that. i'm seriously pissed that i'm having so many problems. i'm gonna work through them and stay ka-t but this is so discouraging. any help is welcome.

[turbonola]

also i had just hotwired my fuel pump. if that helps any.

[neverlift]

its just proof that the hotwire mod increases pressure/flow from the increased voltage... try tightening the bolt that hold the fpr together

[turbonola]

that only increases pressure but i'll give it a try and see what happens.

[turbonola]

shoulda done this first. lol

91 ka24de w/ 96 head w/ s13 cams91 intake manicxracing t2 bottom mount turbo manigti-r t28 w/12-14psi wastegate660cc deatschwerks inj.holley adj. fpr w/ fuel pressure gaugecxracing intercooler setupebay bov w/ jgs vta attachmentsupertech 8.6 to 1 low comp pistons on stock rodsz32 mafsemance tune @14psiebay turboback exhaust

[turbonola]

also my symptoms seem like i'm flooding the motor with too much fuel. i mean the car almost dies at idle sometimes. if i rev the car it's like i have to blow out excess fuel first then it revs great. but as soon as i stop reving it starts all over again.

[480sx]

Time for a aftermarket fuel pressure regulator. Redtop(sr dude, long time nico Vet) told me that a 255 pump will 'overload' the stock FPR and cause your fuel pressure to spike and be inconsistent. Just what iv heard, its not a bad idea to replace your FPR anyway.

I had that same gurgling noise out of the stock one, however never had any issues out of it.

[neverlift]

read again, boffa not the adjustment bolt, the actual body of the fpr....

he has an adjustable fpr 480sx

[480sx]

Pfft, reading.

Do you have a fuel pressure gage? You also have an emance tune.. A realy goofy 660cc injector one. Idk man emance has had more failed tunes than good ones.

[turbonola]

yeah i have a gauge, and it reads fine. i might just hafta take the fpr appart and look at it. i read about another guy who had an emance tune with the same mods i had and he had no problem other than being a little rich.

[neverlift]

yeah its looking like all those "good" emance tunes are just over rich to comp for lack of tune..... diy rom tune ftw

anyway, I have a megan fpr that someone installed 2 diaphrams vs one like it should, I was getting a chatter noise, from it, took the extra off and good to go ever since.

[turbonola]

i know it's not his tune because the car ran great for a few weeks before i had a few vac leaks (which i fixed), a clogged fuel pump sock and filter (fixed both) and then relocated the battery. it didn't get all willy nilly until i relocated the battery to the trunk.

[480sx]

Idk i would try to undo whatever you did(battery location) and see if that fixes it if at all possible. Battery/voltage issues can do some freakish stuff to a car.

Theres also the chance that your running cheap unshielded/poorly insulated wire next to the ECU and its screwing with it. Try to move your cables away from the ECU, reset the ECU, and try again.

[esahuque]

Idk i would try to undo whatever you did(battery location) and see if that fixes it if at all possible. Battery/voltage issues can do some freakish stuff to a car.

Theres also the chance that your running cheap unshielded/poorly insulated wire next to the ECU and its screwing with it. Try to move your cables away from the ECU, reset the ECU, and try again.

i never even thought about that. i'm actually running 4gauge amp wire. i'll try that this weekend when i'm free. thanks

---TURBONOLA---

[turbonola]

Idk i would try to undo whatever you did(battery location) and see if that fixes it if at all possible. Battery/voltage issues can do some freakish stuff to a car.

Theres also the chance that your running cheap unshielded/poorly insulated wire next to the ECU and its screwing with it. Try to move your cables away from the ECU, reset the ECU, and try again.

does the battery have to be grounded to the intake mani also? would it be a problem to run a regular 240sx battery in the trunk and the lawnmower (yeah i said lawnmower) battery up front? can two batteries be run on one car?

[480sx]

Its supposed to be grounded to the intake manifold. Your car *can still run without it though.

Have you tried moving your power wire away from the ECU?

You could run two batteries, wouldnt hurt anything. As long as you didnt run them in series and create a 24 volt system that is.

[turbonola]

ok so i moved the power wire to the middle of the car to the battery, still no change. i then ran a ground from the intake mani to the trunk where i have the battery grounded at and still no change. i also am wondering why my fuel pressure is holding and i found a spot in the return line from the fpr that i can move and make it leak fuel. i'm gonna try to get so soft rubber fuel hose and see if that helps the leak. the hose i have now is sorta hard and regular hose clamps don't work that good. maybe i hurt the motor somehow that's why it won't run right. i hope not. i broke it in half and half, easy 60% and romping on it 40%.

[turbonola]

i forget how to run batteries in paralell (went to mech school in the uscg a few years back) can someone help me out with that.

[turbonola]

nevamind i googled it. lol.

[neverlift]

the lawn mower bat should cut it so long as alt is good and no major audio... my boy actually had an amp and subs off one...

[turbonola]

ok so the plugs we're fouled to hell, but i still have the bubbling sound from the fpr. changing the plugs helped it idle better but it still won't rev to save its life. i guess i hafta find a good stock fpr and see what's the deal. ****s crazy.

[turbonola]

ok so i just read something that made me think. http://www.faqs.org/patents/app/20080232989do fpr's need backpressure? i seen alot of setups that run larger than stock fuel lines feed and return and i've never heard of fuel systems needing backpressure. someone chime in and let me know if you've ever heard of this also please. i very confused now.

[turbonola]

a small excerpt from that link.

"Vapor reducing structure (25) is constructed and arranged to be associated with a fuel pressure regulator (18) of a fuel system (10') of a vehicle. The pressure regulator has an outlet (28) for fuel that is in excess of fuel required by an engine of the vehicle. The reducing structure includes a fuel accumulator (26) associated with an outlet of the pressure regulator defining a volume in which fuel exiting the outlet of the regulator can accumulate. Flow restricting structure (30') is associated with the accumulator and is constructed and arranged to create sufficient back-pressure to eliminate vaporization of the fuel exiting the outlet of the pressure regulator." "In some of today's automotive applications, higher flow rate fuel pumps are necessary to keep up with increased engine demand at wide open throttle. A typical mechanically regulated system uses a fuel regulator to deliver the exact amount of fuel necessary to the engine, and returns the unused fuel back to the fuel module. When that same vehicle is running at idle, nearly all of the fuel output from the fuel pump is directed through the pressure regulator. Due to the design of the regulator, the fuel is sheared as it passes through the regulator, vaporizing the fuel and creating small bubbles. This shearing of the fuel and generation of bubbles in turn causes an audible noise to be generated from the pressure regulator. This noise is often audible inside the passenger compartment and is undesirable to the customer. "

[turbonola]

the return line is a -6an line. the line from the fuel rail to the fpr is -6an also. i'm assuming that the line from the fuel rail to the fpr doesn't matter as much as the return line from the fpr to the hard return line.

[480sx]

Nah thats not your issue dude. I think your worrying about this bubbling sound to much. As long as your fuel pressure is good you should be fine. Start looking elsewhere.

Have you tried moving your power wire away from your ECU?

[esahuque]

Have you tried moving your power wire away from your ECU?

Yeah he did.

ok so i moved the power wire to the middle of the car to the battery, still no change. i then ran a ground from the intake mani to the trunk where i have the battery grounded at and still no change. i also am wondering why my fuel pressure is holding and i found a spot in the return line from the fpr that i can move and make it leak fuel. i'm gonna try to get so soft rubber fuel hose and see if that helps the leak. the hose i have now is sorta hard and regular hose clamps don't work that good. maybe i hurt the motor somehow that's why it won't run right. i hope not. i broke it in half and half, easy 60% and romping on it 40%.

[esahuque]

i don't know what to focus on now. i've taken the fpr apart and everything was normal. so hopefully i can get things worked out fairly soon. i think i'm gonna comp test it this week just to see if i hurt the motor somehow.

---turbonola---

[turbonola]

ok so #4 injector is leaking a little and i just found that i lost one of the little rubber grommet on injector #3. would a bad spray pattern cause the car to run like sh*t? compression numbers were good also 150 across the board on low comp pistons.

[480sx]

Little rubber gromet? You mean the pintle cap?

A small fuel leak and a pintle cap missing wouldnt cause your car to run horribly.

What about ECU trouble codes?

[turbonola]

no not that, the grommet that goes into the intake manifold. then the injector pretty much sits on it.