Hello,

I have been cruising these forums for several years and really haven't posted much. I can usually find my answers with the search. However, I wanted some input on this fuel tank. I am about to buy this 68 with an LS conversion (still learning about LS swaps) and wanted to know what you guys thought about the way this tank was done. It seems safe enough, I believe the pump is in the tank. I am going to verify the pump location and give the car a few more good inspections before I commit to it. I have also attached a picture of the engine bay. I will let you know what exact engine it is when I find out.

Is there anything else (LS/fuel wise) that I should be on the lookout for before a purchase? Thanks in advance for all your wisdom!:)

if it's cheap enough. Those hardware store fittings with 90 degree elbows are very restrictive. Probably work but not the right way to plumb the car. I would definitely replace them.

The black spray paint job underneath always is a negative to me, but that's me. Cut off tailpipes, just looks a bit hacked. If you can buy it right and have no problems fixing the issues then it may be a good project.

What would be the best way to replace the fittings? Would I need to redo the entire setup or just run some better lines/connections?

Replacing a couple of fittings is no big deal.If you can put a fuel pressure gauge on the car and make sure the pressure dosn't drop when you nail it will tell you if the system is adequet.How does the car run?It's not perfect but I have seen worse.The car should have a bulk head behind the rear seat to seperate the tank from the inside of the car to be safe.How is the rest of the car and how much are you paying?If the motor is like a stock 4.8 or 5.3 then the fuel system is not as critical as a done LS6 or stroker.If you can pay a local mechanic to go over the car,it may save you a lot of cash and heart aches down the road.Don't be afraid to invest a $100 or so, to pay for an inspection.
Good luck.

Agreed that the brass fittings should be replaced with some good AN fittings and hose for better flow and safety. I can't tell if the fuel tank has a later model fuel module or if it is just an in-tank pump with a sump although it looks like a module with internal regulator since the return line is looped right back. If it is a fuel module, then I would say it is ok but if it is just an in-tank pump then the sump on the tank not be right and could cause some fuel starvation issues which is always bad for an EFI car. Test drive the car with a 1/4 tank of fuel on a long sustained curve while accellerating and see if it cuts out. If it does then you might consider doing something else for a fuel tank.

As for the engine, if it is a 4.8 then that sux. If it is a 5.3 or LS1 or LS6, thats good. If it is an LQ9 or LS2, even better. HTH

Thanks for all the input! I will definitely replace those fittings and install a firewall. I decided to purchase the car. The fuel pump is definitely in the tank and the gas gauge isn't working at the moment. Can anyone tell what type of sending unit that is on there? I am trying to figure out what exactly I need to do to get the gas gauge working. I have read several posts about converting the ohm rating but I don't know where to start as I don't really know what type I have :D.

I don't know if this helps but there is a purple wire coiled up and not running to anything on the top of the tank.

Purple wire is for fuel level sensor.

I took it for a spin on the freeway to see how she ran. After about 2 min at a sustained 70mph I got some bad cutout in power and had to get off the road. I tried it on the streets and it seems fine at a slower speed. I tried the freeway one more time and right when it started cutting out I let off the gas and pulled into the shoulder. It sputtered hard for a few moments and then died. Does this sound like fuel starvation caused by the fuel lines you gentlemen mentioned earlier?

I took it for a spin on the freeway to see how she ran. After about 2 min at a sustained 70mph I got some bad cutout in power and had to get off the road. I tried it on the streets and it seems fine at a slower speed. I tried the freeway one more time and right when it started cutting out I let off the gas and pulled into the shoulder. It sputtered hard for a few moments and then died. Does this sound like fuel starvation caused by the fuel lines you gentlemen mentioned earlier?

I doubt that the fuel lines or fittings could be causing a fuel starvation issue at highway loads but what sounds more likely to me is that you may have a tank venting issue. If the tank is not properly vented it will starve the engine of fuel. A suction or negative pressure will build in the tank at higher loads and the fuel pump cannot overcome this thus starving the engine. You then slow down to low speeds, the tank takes in a little air and the fuel flow increases enough to support the lower load. Try drilling a 1/4" hole in the gas cap (take it off first of course) and go for another spin. If the problem goes away then you know you have a venting issue and all it cost you is a new gas cap. HTH

The gas cap looks like it is in the trunk. If so you probably don't want to vent it to the trunk. One of those lines coming from the sending unit is probably a vent line going somewhere. Look at the whole system before doing any work. You will probably find a lot of things you can improve on.
Not having a fuel gauge that works really sucks with the efi. Your cut out problem may just be from a near empty tank. I would get all of those lines that are running by the tank up and out of the way.
I'd be concerned about the location of the ECU also. I don't think the OEM ECU's are designed to be located in the engine compartment. Too hot and eventually too wet.
You may have to relocate it to the interior.
Congratulations on your buy. Lets see some photos of the whole car.
Squido

I wouldnt worry too much about the ECU being under the hood. Yours looks like it has pretty substantial cooling fins. If you want to know for sure, try to determine what kind of vehicle it came from, and where it is mounted in that vehicle. That would tell you for sure. I know some TPI Vettes back in the early 90s had engine bay mounted ECUs and so does my '08 Cobalt SS.

With that said, as swcash points out, other ECUs are not designed for such an environment.

-Dave

as above, loosen your gas cap and see if it still does it. I had a problem with a friends car where the fuel filter that came with the system was a carb type, super restrictive. It would be fine idling and cruising at low speeds but any harder throttle or higher speeds would act like it was out of gas (it was because of the filter). Took me a bit to figure out as it was a brand new EZ EFI system with their filter. I did speak to their rep at SEMA and he agreed that the filter was an issue, but they still came with them in the kit. :sad:

Does the pump get louder when this occurs?

GM has been putting their ECU's in the engine compartment since the late 90's. The components used are of the highest quality and can operate in the harshest environments from the hottest dessert to sub zero winters. The circuit boards are coated to protect against moisture and chemicals and the cases are sealed with o-rings as is each wire terminal. This is some serious hardware. Short of mounting the ECU directly on the headers, I doubt you could damage it no matter how hard you tried. It is cheaper for GM to spend the extra money on the components to mount the ECU in the Engine compartment than it is for them to spend the money to extend over 100 copper wires to put the ECU in the passenger compartment. Copper is expensive.

Thanks for all the help. It turns out I was getting a code for the coolant temp that was shutting the engine down. :p I fixed the electric fan relay and POOF no problems since. I appreciate all the input on the fuel system. I am going to redo the fuel lines and make them a little more out of the way when I get some free time. After some digging I have figured out the the ECU and LS1 are from a 98 Camaro Z28. The previous owner didn't have the AIT sensor or camshaft position sensor hooked up. They also had codes that have since been cleared. I look forward to learning all about this car!!!!! Thanks again for the help.