Jesuscookies

iTrader: (1)

Goddamn fuel system!!!! Me and Rzogarbian have been trying to a get this car running all day. With no luck I might add. Maybe someone can chime in with a fresh idea or two. Here is the situation:

We added a secondary fuel rail, 1600CC Injectors, upgraded fuel pump, and a fuel pressure regulator. This was done to support a single turbo upgrade. We also have 850's in the primaries. THE CAR WILL NOT START, or stay started for any length of time. I have checked fuel pressure coming directly from the fuel pump. It measures about 48PSI. However, when I measure the fuel pressure for the entire system (after the fuel pump), I get 10PSI. So there is a leak or something causing the fuel pressure to drop after it hits the lines on top of the motor. I can't physically see a leak, and I am having trouble finding a spot to block the fuel so that I can test for leaks in sections. Does anybody have any ideas on what I can do?

Or has anybody had a similar problem and was able to solve it?

Thanks

Snook

iTrader: (12)

take off your uim/tb/elbow and connect the GND and FP terminals in the diagnostics box over and over. That will push the pressure to what you have it set at and you should find the leak. 40 is an effective basepressure I couldnt get my car started at 48psi. Also if you have an aeromotive fpr the pressure will drop from what its set at to around 20 and then slowly continue to drop. this is normal and when you crank it holds the basepressure. Check your map in your computer that will halt starting... for the 850s its 68% you can change with the commander if you have a pfc.

pm me and I can help out tomorrow on the phone if you need since I just did this

Jesuscookies

iTrader: (1)

Well I do have a pfc, so I will check the adjustment that you are referring to. I also have the Aeromotive FPR, and I think I understand what you are saying regarding base pressure. I have already tried jumping the fuel pump to force pressure up, but this is not working. I will give it another try tomorrow.

Thanks for the help. Might see a PM heading your way.

wonder1and

hmmm... if there is a leak you'd know it and quick...
Possibilities...
1. Clogged like a **** fuel filter
2. Routing of lines incorrect... should go...
FP out, Fuel filter w/ correct direction, hard rail, into engine bay, 2ndary rail w/ 1600's...
to pri rail w/ 850's ... out to FPR inlet, pressure set, fuel out to return to tank.

Are your 1600's on a bosch setup... if so are they setup w/ 10 ohm 10 watt resistors? 1 per injector on either side.

Do you have a broke spring in the FPR... i.e. is it new (I had this happen to me)

Does it sound flooded when cranked?

Where are you testing the Fuel pressure at to get the 10psi reading?
If at FPR you may be clogged up... if so...
Unhook fuel line @ inlet and route using extra hose to bucket... test fire the fuel pump to see if its flowing correctly... (most likly not it)

Check for kinks in the line (Duh)

Good luck!
Ryker

c00lduke

i would also guess that 48psi might be a little much. Get a little B&M fuel pressure gauge and screw it into the FPR that way you know what you are getting. And setting you PFC would def help but mine started with stock settings but just ran crappy.

wonder1and

40psi is recommended by most I've spoken to.

skunks

did you double check that your getting spark? perhaps something is not connected in that department. also, did you pull the sparkplugs and crank her over to see if any gas is shooting out? are you 100% sure that the injectors are firing? what does your injector duty cycle look like when you are trying to start the car?

if your getting compression+spark+fuel, you should get combustion... one of those 3 things are missing

jspecracer7

Run 12VDC to your fuel pump. I did that and I had the EXACT same symptoms you did prior to making my fuel pump voltage 12VDC.

NewbernD

iTrader: (1)

Did you mean to say after the regulator you get 10 psi? Or just farther down the line you get 10 psi? After the regulator isn't a high pressure area so you shouldn't see any there. If you're only seeing 10 psi at the rail I'd believe you have the lines hooked up wrong, your battery is dying or there's a block in the line. What FPR? Did you use the correct port-style AN adapters (with the O-ring) or just screw in the AN male-male fitting.. In some regulators that are made to accept the port adapters (no flare on the FPR side) if you screw in the wrong fitting it will block the internals from sealing properly and holding pressure.

If you're talking about idling (for now), it will have nothing to do with secondary injectors and unless you have a new problem, it's most likely not going to be fixed by running a new fuel pump wire.. (the stock wiring will support fuel pressure to idle just fine.)

You changed the PFC to use 850s, correct? Extra fuel (850 instead of 550) and the 25% extra fuel pressure (should be 38-40 with the car off or when you pull the vacuum reference line) might be too much fuel..

I'd start looking at every piece you've changed one by one and making sure it's doing its job.

Good luck.

Jesuscookies

iTrader: (1)

I do not have the routing going this way. It goes fp--> to fuel filter -->to hard lines in engine bay--> to fuel pulsation dampner -->to primaries. From here it goes out to a fuel line that connects to a banjo bolt that feeds the secondaries---> to FPR -->to return line. Is this hooked up incorrectly?

jspecracer7

mis-read. It's hooked up correctly.

Jesuscookies

iTrader: (1)

NewbernD,

I checked the fuel pressure at the pump. This was at 48PSI. I then checked it at after the FPR, which sounds like it is unnecessary according to your post. The FPR is an aeromotive, running a steel braided line into AN fittings.

I did change the PFC to run 850cc, but I do not understand the second part of this line can you explain?

Sonny

Have you adjusted the Aeromotive regulator at all to play with the fuel pressure?

You need to read the fuel pressure coming from the feed line of the pump that goes into the primary fuel rail. If you're only getting 10 psi of fuel pressure, the car will not start. It sounds almost like the adjustment screw on the FPR is backed all the way out.

Sonny

Jesuscookies

iTrader: (1)

Fuel pressure is 48psi from the feedline. I have messed with that screw, and have no idea where it should be.

93BlackFD

10psi AFTER the regulator sounds normal to me? is it not?

MazdaGuy42

iTrader: (1)

While you are down in the area you might think about eliminating your fuel pulsation dampner. Will save you a nasty mess and possible engine bay fire in the future. check the "how to" section on www.banzairacing.net Chris takes you through step by step. It has worked outstanding on my car. Plus it's like $3.00 to do.

D.

GoodfellaFD3S

iTrader: (213)

In the Injector screen, you want the "FR-PR" (front primary) line to read 68% and +0.04ms Injector lag time (vs the 100% and 0.00 original settings). Do the same for the Rr-Pr (rear primary).

Hope this helps

NewbernD

iTrader: (1)

My mention of 25% extra fuel pressure was reflecting your 48 PSI... iNormally it should be 38-40. 48 is about 25% more.

Did your regulator come with fittings that used o-rings? I ask because many people mistakenly use fittings that look like this:




instead of fittings like:




and when you screw in the style on the top, the extra length prevents the piston inside from sealing and holding pressure. Because it's cheap, I'd go pick up a small gauge to put on the FPR anyway so you can watch fuel pressure there.

Jesuscookies

iTrader: (1)

NewbernD,

I checked and I do in fact have the fitting that you say is incorrect, should I change both of them for the one that is shorter? Can I just cut the "nipple" off of the longer bolt? do I need to have this shorter bolt on both sides?

And yes they have an o ring on them.

NewbernD

iTrader: (1)

You can just trim off the flared part. Grinder would probably be easiest. I used a countersink bit to clean up the bore a little bit.

I'd also still get a pressure gauge for your regulator so that you don't have to interrupt your fuel system to measure pressure..

Hope this does it for you.

rxrotary2_7

Dave, this is on the car you bought to fix up? i am guessing this is one of the things that was "wrong" with the car when you bought it? if so, why not just pull the right fittings out of the kit i sent you for your personal car for now....

Jesuscookies

iTrader: (1)

Cuz it's mine, mine, all mine!!!!

Seriously though, I have been through my kit a couple of times for parts.

Jesuscookies

iTrader: (1)

Thanks Bern I will cut grind these down on monday. couple of questions for you on this.

Should I install the guage before the fuel enters the FPR or after?

Do I grind those bolts down on both the in and out on the regulator?

NewbernD

iTrader: (1)

On most aeromotive FPRs there's a provision for a 1/8 NPT gauge right on the regulator.

Every port on the regulator uses the same kind of fittings so yes.. both INs and the OUT, and if you use a plug for one of the INs, do it too.

Jesuscookies

iTrader: (1)

THE BEAST LIVES!!!!

FPR had the fuel feed, and fuel return both going into the, "IN" ports, so no fuel pressure. We did not realize that there was an additional port on the bottom of the FPR until we pulled the FPR off of the car and looked at the bottom of it.

Anyways, it was good learning experience. I figured out how the fuel system works, and learned a little more about the car.