Real quick, 305tbi was in the 91 camaro.* Put a Ram Jet 350 in place of it and replaced the fuel pump with a holley intank pump.* Upgraded to a procharger, put the inline fuel pump in and the old return line in the engine bay is blowing vapors after running it around town for few hrs.* I talked to the guy that did the install and he stated block the factory 305 return line and drill 2 3/16 drill bit holes in the white part of the cap.* I did that too.* Fueled camaro up, few runs around town, got home, fuel on driver quarter.* The fuel tank was bubbling and cap had very little pressure but the fumes were CRAZY.* I need to know what else to do, I know I need to check the vent tube, or could the secondary pump get re-wired for when boosts kicks in.....What you think or any ideas,,,,,,Thanks

 

real quick..........check the white plastic vent thingy

 

doesn't the ram jet use a return line i've never used a ram jet before just curious

 

Its been awhile but according to my ram jet book it states
that it has a return line. I work on the road all the time so
weekends are my tear and fit days. this wknd I will be checking for
vent tubes and run maybe a new return. What you think steel braided
or just fuel hose or hard line 1/4in through the fill neck!!!

 

Wow, I totally missed that the first time. I was thinking that the person that installed the Ramjet installed a new return line. It sounds line you have one tank with a pump feeding another boost pump to the Ramjet.............and then no return line. You need a return line from the Ramjet to the fuel tank. It is extremely dangerous to run that engine the way it is now and the installer could have liability problems.

You need the return line to fun from the Ramjet fuel rail return port to the return port on the fuel sending unit. Do not try messing with the filler neck.

 

yeah, I agree. Guy who installed that is a moron. Def never mess with your filler neck.

If that is not a "micky mouse" way of doing things, i don't know what is.

Get a nice 6 or 8 AN return line. Hard or rubber, doesn't matter. your prefrence.

 

I was going to do the filler neck so I wouldn't have to tear the tank, rear, torque bar...etc. I believe there is a return line on the motor. Every thing was fine with the car, hell I ran 5 HotRod Powertours in it. This ram jet is the first that they(Chevy Perform.) made, no O2 sensor, etc.
I have a intank pump with a inline pump that the inline pump runs all the time, I have the fuel actually bubbling in the tank this past weekend after closing the old 305 return/supply line by the fender on driver side and drilled
2 3/16 holes in the cap to releave the pressure....I Feel this is not going to be quick fix lol

 

OK, so now you write like you do have a return line from the Ramjet to the fuel tank. Based on that:

Before you go messing with the filler neck or dropping the tank, I would check the white breather thingy. It is above the rear end. The fuel tank has a line going to it. It is a white plastic round breather. You don't need to remove the rear end or tank to check it. It is easy to get to.

If that is OK, next check you evap. can and that you are not blowing boost through it to the gas tank. Normally there is a check valve built in. If you blew the check valve, then you will pressurize the tank. It is highly possibly that you have broken this assembly and that is how you are pressurizing the tank. You can temporarily test this by removing the line from the evap. can to the Ramjet (plugging both the Ramjet fitting and line to the evap. can), and unplugging the electrical connector on top of the evap. can. Test drive to see if pressure builds. Or you could try to blow through the line and see of it bubbles in the tank.

EDIT: Maybe he just connected up the evap. lines wrong. You could check that first. It is quick and easy. If the lines were backwards, then it would pressurize the tank under boost and not allow the pressure to be relieved due to the check valve.

 

Hey Boss, I thank you for all the info. Heres what I found, was able to get home to play with the camaro thurs. and fri.

Well I checked the little white hanging thing by the tank. I blew in to it after taking it off the line, great operation, its venting.

Checked the supply and return lines, (which it has a RETURN line) factory size. Supply is the size for a tune port car I guess 3/8's maybe.
The return I believe is 1/4. Guessing on sizes but all factory.

I have vented the non-vent cap with 2 drilled 3/16 holes. It is now throwing fuel out the fuel door. lol

The canister you were talking about with the carbon, it hasn't been hooked up for 4 yrs, and the line stayed open all that time. Still have the can but MSD box was put there during the install of the pro-charger.

I talked with the guy the specializes in 3rd gens, hes the one that installed the motor 4yrs ago. I and him believe that I have too small of a return line, and discussed that the hose would be good at 1/2'' in size all the way to the tank. I can see the flex hose that is factory on the tank, do you think if I run the new line the full lenght and hook to the factory flexline going into the tank cause the fuel to still over heat and air-rate the fuel.

I'm trying to be an *** and not drop the fuel tank, but I want it right. you know! Was going to change fuel tank to a 24 gallon tank from fuel safe. Too much money they want but it is certified fuel cell.