Fuel pressure question - HELP!

[PKRWUD]

Originally posted by Stang_ROTY
Chris,

She is beautiful!! Awesome job bro!!

I've been trying to find a fuel leak for a while (since before I started this thread) now but can't locate any liquid. Last time, when my AN fitttings were leaking it was easy to tell. Injectors aren't leaking either. Steel braided line is brown in some spots but no fuel leaking. What about the possibility that my fuel line being so close to the tailpipes is boiling the fuel? What are the chances that this is happening?

let me clarify what I meant; You don't have an external leak, but rather an internal leak. Fuel injection has to have pressure to work, and when you shut off the pump, there is supposed to still be pressure in the lines so that it will start right away. If you have an injector that's become stuck open, it will slowly leak the fuel into that cylinder, dropping the pressure. Or, if the regulator is bad, it will allow the fuel to drain back to the tank, reducing the pressure. Another common problem is the pump itself, or the hose in the tank becoming cracked, allowing the built up pressure to fall when it allows the fuel to drain back into the tank. A leak in your fuel system doesn't have to be external to cause problems, just like a bad internal seal in a master cylinder can give you lousy brakes, even though you don't leave puddles of brake fluid everywhere.

Originally posted by Stang_ROTY
What damage, if any am I doing to this engine by having difficulty starting cold?? Oil pressure is at 60 lbs when cranking.

In the short term, not much. Anytime it takes longer for an engine to start, you are incresing the wear and tear, but it's not really significant, yet. Usually, the problem causing the hard starts will completely fail before you do any other damage. Still, you need to fix this problem right away.

Originally posted by Stang_ROTY
Regarding oil & Lucas additive, since I have the 7 qt Canton 351 double sump swap pan should I use 6 1/2 qts. of Mobil 1 and 1 qt Lucas??

Sounds like a good plan to me.

Originally posted by Stang_ROTY
Also, I am developing a significant oil leak at what appears to be the back of the oil pan. Seems like the rear (of the 4 piece gasket) is being squished out a bit. Does this mean my engine builder cranked it too tightly and I need to pull this sucker again to replace the .50 gasket?? Ouch!! Is this common amongst the swap pan's??

Thanks and let me know where that beauty is going to end up, she looks sweet!

Yup. Sounds like it to me. If/when you replace the gasket, you first have to make sure the gasket surface is flat and true, and not bent from over tightening. The best way to do this is with a flashlight and a big piece of glass. Set the glass on a table, turn on the flashlight, and set in on the glass, then set the oil pan over the flashlight, on the glass, and turn out then lights. Anywhere that you can see the flashlight shining from under the pan is a place where the pan is bent, and needs to be straightened.

Thanks for the kind words.



Take care,
~Chris

[PKRWUD]

Originally posted by Dark_5.0
PKRWUD is awesome isnt he..

He always seems to raise the IQ of everyone around him.

lol, Tracy, if I'm so smart, then why aren't I independently wealthy yet?



Thanks though.

Take care,
~Chris

[Stang_ROTY]

No problem! You are the man as for as I'm concerned and anybody who thinks different can talk to me

So is the best approach at this point to replace the regulator? I found an aeromotive version that'll work and provided my credit isn't maxxed (this stuff isn't cheap as you well know) I can get one here tomorrow. Since it's old I am going to pray that it's the source of the problem.

If the answer is yes to the above question what's the best approach to relieving fuel pressure? I imagine that I can't just go unscrewing the AN fittings :-) .......or can I becuase the regulator isn't holding pressure anyway?

[Stang_ROTY]

Well, I called Summit and they have one in stock but they said "once you run fuel through it, it's yours so you better be 100% sure of what the problem is." I guess I better make sure that it's the regulator before I order. Should I check for a stuck injector (is that even possible after only 800 miles??), or are you confident that from the information I've provided it's the regulator?? If I should check for the stuck injector, what's the procedure? Same for the fuel pump. I better check all the possibilities before I start ordering parts.

Thanks

[PKRWUD]

A stuck injector wouldn't be able to relieve 40psi in 1 second. The only other possibillity is the pump, or part of the line in the tank being cracked. Follow the return line going from the regulator to the tank, and locate a section that doesn't have steel braid. Turn on the key, and have someone clamp some visegrips on that part of the hose, then turn off the key. Turn it on again, and after a second, turn it off again. If your pressure holds, it's the regulator.

If you can't locate a section of the line to clamp, then you are going to have to do it differently. You will have to make your own tool. You will need a replacement fuel filter. When you have one, remove your old one, and cut off the tubes that go in and out of the filter, clean up the cut ends with a file, and clamp a piece of fuel line over the ends, so that it is the same length as your new filter (in other words, you are substituting a piece of hose for your filter). Have someone turn the key on and off a couple times, and then when it's on, clamp a pair of visegrips on the rubber hoe you just installed. Turn the key off, and check the pressure. If the pressure is holding, then the problem is in the tank, and is either the pump or a cracked line to the pump. If the presure goes right to zero, it's the regulator.

[Stang_ROTY]

Chris,

You won't believe this. I contacted the Aeromotive tech dep't yesterday as they are the manufacturers of the Cartech line of fuel systems. They said that there is no check valve in these systems as they aren't designed for street use. They also said the regulator wasn't designed to maintain pressure. I had him listen to the pump itself (which he said is upposed to run loud)and we walked through doing a vac test on the car (which ended fluctuating at 10-12 inches....is this bad or good?) and he asked me what type of pressure gauge I had. I told him it was a liquid filled Jegs mech gauge and he started chuckling.

HE explained to me how he's been receiving at least 12 calls weekly on these gauges. He asked me to put a hair dryer to the gauge and you won't believe what I found! I had the car running and I cranked the dryer on the gauge and the f%&^ing pressure dropped to 30 psi!! I then took a bad of ice and placed in around the gauge and it increased to 40 psi!! Can you believe it!?? I paid like 40 bucks for this shitty gauge and it almost cost me a 1000.00 fuel system, as I was considering purchasing a new system. I guess maybe that's why she wasn't leaning out.....makes sense now. The pressure is maintaining but it's the blasted gauge that's at fault. What do you think?? I think I found the problem.

[eeh1025]

Hey guys got a question for you, the vaccum on my Regulator, when i have it disconnected the car seems to run at a better idle and when i hook it back up it sound like i have a big cam, the idle goes up and down, Is it okay to take the vaccum off and plug it or do i have a problem with something. thanks alot.
Ernie

[Dark_5.0]

When you unplug it your engine gets more fuel and it sounds like it likes it. You need to turn your fuel pressure up a little and reconnect the hose.

Usually if you run without the vacuum hose attached you will run rich at an idle and at low RPM's.

[Dark_5.0]

BTW: killer set-up.......I bet it hauls some major @ss.

[eeh1025]

It sure does
it is just this pain in the a** 86 gt i have with the fuel problem, so is it okay to keep the line off and how do i adjust a stock regluator, if you even can. thanks man

[PKRWUD]

Originally posted by Stang_ROTY
Chris,

You won't believe this. I contacted the Aeromotive tech dep't yesterday as they are the manufacturers of the Cartech line of fuel systems. They said that there is no check valve in these systems as they aren't designed for street use. They also said the regulator wasn't designed to maintain pressure. I had him listen to the pump itself (which he said is upposed to run loud)and we walked through doing a vac test on the car (which ended fluctuating at 10-12 inches....is this bad or good?) and he asked me what type of pressure gauge I had. I told him it was a liquid filled Jegs mech gauge and he started chuckling.

HE explained to me how he's been receiving at least 12 calls weekly on these gauges. He asked me to put a hair dryer to the gauge and you won't believe what I found! I had the car running and I cranked the dryer on the gauge and the f%&^ing pressure dropped to 30 psi!! I then took a bad of ice and placed in around the gauge and it increased to 40 psi!! Can you believe it!?? I paid like 40 bucks for this shitty gauge and it almost cost me a 1000.00 fuel system, as I was considering purchasing a new system. I guess maybe that's why she wasn't leaning out.....makes sense now. The pressure is maintaining but it's the blasted gauge that's at fault. What do you think?? I think I found the problem.

Figures. Well, since you drive it on the street, you might want to replace the regulator. I've never heard of one that doesn't maintain pressure, but if that's what the guy says, then I guess it must be. For a daily driver, you want it to maintain pressure.

Take care,
~Chris