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Discussion Starter · #1 ·
I dont know how many people are FI savvy, but it doesn´t matter, I´m up for any idea´s.

Okay so tonight I´m supposed to drive to Vegas to show my old roommate that con´d me into boosting the escort my now boosted escort

At the track last week I was having a problem with my fuel pressure demand going to high and the pump cutting out. Okay, well last night and this morning I ran into a new prob.

Now, its been running fine since returning from the track a week ago, and all of a sudden the scort will still show 5psi but the pull will be gone.

The only thing that makes sense right now is I´m blowing out the spark, so I need new plugs and to check and make sure I´m running the .038 gap I normally run.

I can hear a leak in my gas tank that I never heard before last night. I can hear pressure leaking out of the tank. Does anyone know if that can affect my fuel flow causing a super lean burn thats intermittant. Yeah, it will fall over on itself with boost, but then come right back if I keep my foot in it.

Any thoughts ?
 

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15-02-2003 at 04:56, TheBlade wrote:
I can hear a leak in my gas tank that I never heard before last night. I can hear pressure leaking out of the tank.
Any thoughts ?
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For what it´s worth, here´s my limited understanding Blade:

I believe that air needs to be able to enter the fuel tank in order to allow fuel to leave. If the tank were a sealed system then I think the fuel supply to your engine would be shut off. As I understand it the only pressure in the fuel system is caused by the fuel pump and injectors.

As for hearing a leak in your tank that you never heard before, I cannot imagine what´s up with that, or how you could hear a leak there anyway. Sorry I´m not more help.
 

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Discussion Starter · #5 ·
Yeah my ignition system is the MSD and yeah it does feel like the timing is going all screwy.

The leak is by the left rear tire. When I fill my tank all the way up you can see the gas streaming down onto the ground. Also you can hear air pressure coming out of the tank when I get out of the car, like when you unscrew the gas cap but the sound lasts longer.

Yeah, I checkvalved the line to the vapor canister for the turbo install, so I´m sure its not the motor pressurizing the fuel tank like that.

The real question is why it shows positive pressure numbers in the manifold even if its falling over on itself.
 

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Well as for the leaking gas tank, are you sure its not leaking from around the gasket on the fuel pump. When I first bought my car it leaked horribly from there whenever I filled my car even though it looked like it was near the left rear wheel. In my case someone had actually left the gasket out completly. I grabbed a new one from the junkyard (cause you can´t by the gasket itself) and the problem has never returned. Hope that helps a little.
 

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my older bro had this problem w/ his 300zx.......

as it goes...he blew the 2 gaskets around the turbo inlet and output piping......blew an oilcooling line....

and finally blew the turbo...

i´d say, check the gaskets, timing, fuel deliver......other than that, i dunno
 

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What is your base timing? how much timing are you retarding per psi? if your distributor timing is set a base, you don´t need to retard alot under boost. for 5psi, maybe 1/2 of a degree or less per psi of boost.
 

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Have you checked the plugs yet? If you were leaning out on the track it´s quite conceivable that you simply melted down some ground leads. BTW, are you running multi lead plugs? I´ve read that they´re a good idea for boost situations where the extra heat of combustion can melt leads down... helps to keep timing more consistent. Normally I don´t reccomend multi lead plugs because they´re made for economy, not performance, but you may want to look into NGK´s two and three ground lead plugs. NGK makes some good cheap performance spark plugs.

I´m not familiar enough with your fuel system (or the one on my scort) yet to make any educated predictions. If fuel is leaking out of the tank though, I´d reccomend checking that pump seal 2EGTs mentioned. Also, check the fill neck carefully. I´d imagine there´s a rubber hose between the tank and the filler neck, that´s another possible culprit. I´ll make an uneducated guess that the leak has nothing to do with the way your car is running right now (unless the leak is from a pressurized fuel line).

How does the engine sound under boost? Strong? Quiet? Rough?
 

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Discussion Starter · #10 ·
Well, The leak is huge now. I think there´s a rubber connector from the tank to the filler neck, I´m pretty sure thats where the leak is at and I can now assess that there´s no pressure in the tank. That would be my problem with the fuel sloshing around.

Yeah Orlando, I dont have the timing pulled back much at all. I can hear what sounds like detonation, but not nearly as loud. But I´m almost starting to think its the actual MSD box making the sound. Just can´t pinpoint it and drive at the same time.

Also, because the AFC wont read rev anymore (it died), I´m using that 12:1 fpr. I´m sure what´s happening is as the density-altitude changes up here I get dangerously close to a situation where I´m not flowing enough fuel under pressure, or my fuel pressure is giong too high and killing the walboro pump. (I´m sure the leak is a cause and an effect of this fuel pressure riser and problems)

Plugs, I´m running NGK V-powers right now. I put them in when the car died and I just assumed I burned a plug from a lean burn. Come to find out my plugs are looking awesome. They do show an over fueling problem and a lean burn too (this has become the norm though).

The timing has been changed so much I dont know where its at anymore. I´ll be putting a timing light on it this weekend sometime.

I´m sure my problem is just fuel. I need lower pressure and just more flow, but I can´t throw the bigger injectors in because I can´t control the fuel for them without a computer.

BTW--- The scort in Las Vegas sounded like a Rally WRX on crack. Had the same rrrrAAARRRRRRRRReeerRAAAARRAAAWWW--PaCHHHEEEEESH!--rrrrAAARRRRRRRRReeerRAAAARRAAAWWW :-] To put it simply it sounds pretty bad-ass. And when I can get enough fuel to the motor under boost it pulls freakin hard :-W
 

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Discussion Starter · #12 ·
No I dont, the thing has never worked right though.

I tried T-Taping all the connections like Orlando told me to. Everyone I know out here told me it wouldn´t work, but I tried it....I would set all the values to 0 so it wouldn´t modify the airflow signal at all, and as soon as I would hit boost the car would buck really hard. So I soldered all the connections into my wiring harness, and that´s when it stopped reading Rev, even though I checked the continuity through all the wires and everything showed to be good. Besides it reads rev off of the MSD box. Its all just really weird and has me really really upset about it. Its the one reason why some days I feel like giving up on the whole project and buying a honda.
 

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Its the one reason why some days I feel like giving up on the whole project and buying a honda.
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Yikes!! :-0 That´s crazytalk! Have you looked into standalone engine management as opposed to the piggyback style AFC?

Simple Digital Systems has a pretty nice setup for cheap.. if you don´t mind programming it yourself. They also have systems that work well with MSD ignitions. That turbo 320i guy I mentioned before uses it and has been thoroughly impressed with it. I´ve got no firsthand experience with it though, so don´t take my word for it ;-)
 
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