PDA

View Full Version : Too much fuel pressure - with no boost yet



whytry
04-29-2006, 10:12 PM
Hi all, as most of you know I am getting the camaro ready for my F1R that should be here next week. I have the fuel system plumbed and I turn the pump on the check for leaks, noting major 1 small leak not big deal tighten the fitting all good. So I add my Fuel pressure gauge to the mix so I can see where I am at pressure wise. I turn the pump on again pressure goes well above 15 PSI, and fuel winds up coming out of the carb like a mini geyser!!! Shut the pump off. Go back and check to make sure nothing is pinched or anything and all looks to be fine. Got the manual for the Aeromotive 13204 regulator, and went to adjust fuel pressure. Went counter clockwise per directions to lower pressure (3 full turns) and still over 15 psi and the geyser is still there!! Can anybody give me some suggestions? Does the car need to be running to adjust pressure? I have the A1000 pump and all line sizes are ran per Aeromotive's instructions.....

Any help would be appreciated....

It's late been smelling gas all day, changed intake and carb as well, stupid buddy of mine thought it would be a good idea and get a good laugh out of cranking the motor over after I pulled the distributor out. Now after the new intake and carb are on put the distributor on and it bellows likes it is trying to combust in the tail pipes. Is my timing off or am I 180 out?

speedster
04-30-2006, 05:24 AM
A quick check for 180 timing.
If valve cover is off:
Spin engine with a rachet on the damper and check for the timing mark after the intake valve of #1 is closes.
If valve cover is on:
Pull spark plug #1, stick your finger over the spark plug hole, spin the crank with a ratchet, when the pressure forces you finger off, look for the timing mark.
Not trying to be condescending, just remember the 4 cycle basics - Intake, Compression, Power, Exhaust.

As far as the 13204, I know it sounds dumb, but double check to make sure you have the inlet, return, carb and gauge connections in the proper regulator ports. If you think they are OK, disconnect you return line near the fuel tank if you can reach it and have someone hold the fuel line over a gas can. Flip the pump on and you should see it flow like crazy out the return line. If not, you have a problem. Past that, you probably want to get an Aeromotive tech on the phone [913-647-7300] since you already adjusted (CCW) the pressure down. Hope this helps a little.

ProdigyCustoms
04-30-2006, 05:38 AM
Running the car may increase fuel pressure as voltage goes up from the alternator putting out. Sounds like a regulator problem for sure. i would back it off a lot and see what happens.

You are welcome to call me anytime, I am around today if you need me.

Let me know when your baby arives.

Thanks Again.

camcojb
04-30-2006, 06:24 AM
How big is your return line to the tank, and how/where does it enter the tank?

Jody

Blown353
04-30-2006, 09:15 AM
Ditto what Jody and the others said.

A laundry list of things I would check for:

1. Regulator plumbed properly

2. Proper spring in regulator (some regulators come with a heavy and a light spring for different pressure ranges, if that's the case did you put the right one in?)

3. Regulator plunger not frozen (pull off the return fitting, you should be able to move the plunger manually)

4. Return line restriction (diameter, tight bends, 90 degree pipe fittings.) For a carb'd setup you'll need the return line to be the same size as the feed line, and you don't want to use any restrictive fittings-- the 90 degree machined pipe fittings are the worst in that regards.

The adjustment screw on the regulator is on the backside of a diaphragm, you can back it off and remove it and the spring entirely for testing-- this will put the regulator at the lowest pressure setting and let you know the backpressure in your return line.

whytry
04-30-2006, 04:03 PM
I am running the 13204 Aeromotive regulator, -10 feed and -8 per aeromotive's tech team. The regulator did not have any other springs in the box when I got it.

I am running the -8 return to the top of the tank and into the tank on a new -8 fitting on the top by the factory sending unit. Also inside the tank I am running about 4" of -8 line so the fuel would not splash into the tank on return....

I might go play with it today, so I might be calling Frank.

Hey Jody you still able to come by sometime?

shmoov69
04-30-2006, 08:02 PM
Sounds like a return is clogged or something. Back off the adjuster all the way and it should be fine. I had a Mallory regulator and it kept up with the A1000 until it got under boost and then it would not keep up, so I just put on the Aeromotive one yesterday hoping to solve that problem. I am running 1/2" aluminum feed and return to the sump in my tank with it and have had no prob's on the PT last year, other than the fuel boiling!
Let me know what you find out so I know what to expect when I get mine going again!

camcojb
04-30-2006, 08:32 PM
I am running the 13204 Aeromotive regulator, -10 feed and -8 per aeromotive's tech team. The regulator did not have any other springs in the box when I got it.

I am running the -8 return to the top of the tank and into the tank on a new -8 fitting on the top by the factory sending unit. Also inside the tank I am running about 4" of -8 line so the fuel would not splash into the tank on return....

I might go play with it today, so I might be calling Frank.

Hey Jody you still able to come by sometime?

Let me know when!

Jody

whytry
05-01-2006, 03:36 PM
I should have a nice big present at my house today or tomorrow, so this weekend would be perfect, but I will out of town, (baby shower) down in the bay area, should be back here on Monday, but then maybe the weekend of the 13th? Or one night during the week if you are up to it?

I will check on the fuel pressure today when I get home from work and post up what I find out.... Then check return line....

whytry
05-01-2006, 06:51 PM
Finally got home, took adjustment all the way off and then reinstalled to where it is just barely on and tighten it down. Turned pump on and still has over 15 PSI pressure. Pulling the tank hopefully tomorrow and taking out return line per you tests. Thanks guys, will keep you updated once I get to work on this....

Y-TRY
05-01-2006, 08:54 PM
You haven't started then engine yet, right? This is just running the pump and not engine? Did you plumb the regulator as I suggested in an earlier thread?

If you are sure everything else has been covered: The main thing to ME is the idea that you are submerging the return line into the fuel in the tank...

If the line is submerged, it requires a good deal of pressure to push the return-line fuel into the tank. Forget all the "kinks" and 180's and whatnot. The tank fuel is pushing against the return line fuel a great deal, because of gravity. Imagine blowing air, through a straw, into a milk shake, feel the resistance? Well, in your tank, your pressure has to exceed the gravity-pressure of the fuel around it, which can be very great.

IMO- Dump the idea of not splashing the fuel. Any splashing only disrupts the fuel on the surface, and you are pulling from the bottom anyway(right?).

To test this theory, drain the tank to a level below the return line.
Then do your pressure test again. If you see the pressure drop, and you stop blowing fuel out the vents, then pull that return line and trim it. It's always the smallest details that go overlooked.

whytry
05-04-2006, 07:20 AM
Update - I pulled the tank out last night to check on my lines. All seemed to be fine, no kinks, I did however pull the hose off the inside of the tank on my return line. Then I pulled the return line off the regulator, it seems as if there was a small piece of debris holding the spring up or the spring was stuck because I pushed the spring a little and not much happened tried it again and it seemed to move more, so I turned the pump on and pressure seemed be ok, right around 6 psi. plugged the return line back in connected it to the tank and did another test, 6 psi, so put the tank back in place and all is good now. Thanks everybody!!!

Now I can get to the fun part.....

speedster
05-06-2006, 04:15 AM
...it seems as if there was a small piece of debris holding the spring up ...

You are using good fuel filters, Right ?

whytry
05-08-2006, 09:24 AM
Yeah, I am running the Aeromotive ones they recommend, but this looks like it was on the line post filters, I ran the pump into a bucket before the final plumbling was installed, but I still got some in there. All seems to be good now....

Thanks!

Y-TRY
05-09-2006, 08:34 PM
Well, cool. Glad to hear it's coming together. I'm anxious for more updates...