do you thing I could have lost fuel into the coolant system??

[myblack98gst]

Now that I have you thinking I am a moron hahha..

I had a mitsu MLS headgasket that was not sealing correctly it was pressurizing the coolant system from 3 cylinders. I have a new gasket ordered just waiting on that. but I have had an issue with running out of fuel up top I was thinking about it today is it possible that since I am loosing pressure to the coolant system would it not also loose some fuel as well.

I am litterally adding 10-20% or more fuel in up top not just where boost comes on but on up around 5,500-6,000 rpms.

for the fuel it is a 255hp pump, 3/8 fuel hose from the tank to the rail, aeromotive a-1000 regulator, and 1000cc injectors. I should have plenty to support the mediocre 20psi I run on pump gas (sc61)

 

[cruisintalonawd]

how do you know that you dont just have a bad radiator cap???Have you performed a leak down test? and what the car doing when it runs out of fuel

 

[myblack98gst]

how do you know that you dont just have a bad radiator cap???Have you performed a leak down test? and what the car doing when it runs out of fuel

because when I pulled the head off there are black streaks from cylinders 1,2,3 leading directly to the coolant passages on the front side of the block..

it does not have any issues untill I am running 20+ psi after talking with the guy who did all the machine work on the motor he says his turbo mustangs (2,500+ hp) have the same issues if you don't coat the gasket good with copper spray.

the fuel is just a theory at this point I am going to have to wait until I get it put back together to see if that fixes the problem I was just wondering if anyone else on here thought that it was a possibility for something like that to even happen. But it does suddenly lean out from running 10.9 then shoots up to 12.5 range without known reason.

 

[twicks69]

because when I pulled the head off there are black streaks from cylinders 1,2,3 leading directly to the coolant passages on the front side of the block..

it does not have any issues untill I am running 20+ psi after talking with the guy who did all the machine work on the motor he says his turbo mustangs (2,500+ hp) have the same issues if you don't coat the gasket good with copper spray.

the fuel is just a theory at this point I am going to have to wait until I get it put back together to see if that fixes the problem I was just wondering if anyone else on here thought that it was a possibility for something like that to even happen. But it does suddenly lean out from running 10.9 then shoots up to 12.5 range without known reason.

It is sounding like your fuel pump isn't keeping up -- how old is it? What is your base fuel pressure at? You might want to replace the in-tank pump, and you may want to install a walboro 255HP in-line fuel pump, to add efficiency to the equation.

As well, what did you torque your head studs to, and have you re-torqued them since installation, before the head was lifting?

 

[turboglenn]

I'm thinking along the lines with twicks69 as far as the fuel. My HP walbro 255 started doing the same thing after going from an OEM FPR to an AFPR by aeromotive. I ended up re-wiring the pump like i should have from the start and it fixed it.

As for your head gasket leaks, i'm stumped on that one. I've run that much boost daily on a stock HG without any issues. Maybe it's something to do with the MLS gasket and thge head bolts you're using. Are you running ARP head studs?

 

[myblack98gst]

yes it has ARP head studs in it the headgasket was re-used once and when I re-installed I did not use copper spray to help out with the sealing. the pump is re-wired with a 12gauge going directly on the pump I am either going to make my own sending unit and do 2 intank 255's or sump the factory tank and do one big pump because my power goals this year are going to exceed the ability of a single pump.

 

[cruisintalonawd]

theres your problem you NEVER reuse a head gasket

 

[twicks69]

yes it has ARP head studs in it the headgasket was re-used once and when I re-installed I did not use copper spray to help out with the sealing. the pump is re-wired with a 12gauge going directly on the pump I am either going to make my own sending unit and do 2 intank 255's or sump the factory tank and do one big pump because my power goals this year are going to exceed the ability of a single pump.

Never reuse a head gasket. It is also imperative that you have a perfectly flat deck and head surface when using a multi-layer steel head gasket. If you were using a factory head gasket or a copper head gasket, you would have more room for error because the materials would "squish" and fill the minor imperfections. Also, it is extremely important to use the ARP moly assembly lube, and torque them properly in the correct sequence; then re-torque them after some heat cycles through the setup, then check them regularly (depending on your usage) -- I retorque my studs around 1-2 times a year--I have had no problems with the same set for over 5 years. Now I am just running L19 studs instead (just installed).

Also, a single walboro 255HP in-tank with -6AN feed line, and an in-line walboro 255HP fuel pump to 1000cc injectors is proven to easily do 1000HP at the crank. If you have doubts, then you should look at my setup -- that is what I use with absolutely no problems. I am running a 8ga power wire with a 60A in-line tube fuse to a 5-prong relay (2-signal prongs), then 8ga power wire from the relay with 15A in-line fuses to each fuel pump. Works perfectly.

This route is also extremely cheap and easy to do, and can handle 50+psi of boost with a 43.5psi base fuel pressure. If you are going to be going larger than a GT4294R, then use 1600cc injectors with this setup.