Firebird Fuel Pump Replacement: "Trap Door" Method
FormulaForce
03-16-2012, 10:23 PM
Some weeks ago I posted a thread (you can see it in this section, about 2 down from this thread) asking about an alternate method of replacing the fuel pump in my 1995 Formula. This is often referred to as the "trap door" method, and involves cutting through the sheet metal of the rear hatch area (over the fuel tank) and reaching the pump that way. The only other method (actually, the RIGHT way to do it) involves lowering the rear axle, removing the rear exhaust, and removing the entire fuel tank. Expensive to have done by a mechanic, and very labor intensive.
I closed out that thread because I thought I had the car sold, but the deal soured and I ended up going through the procedure anyway just to get it running. I had no money to hire someone for the traditional method. If you are considering performing this procedure, PLEASE READ THIS THREAD!
First, there are a number of videos you can see on the internet that explain how to do this. They are quite informative. You have to remove the rear carpeting and trace lines to cut out a panel roughly 7 1/4 inches wide X 12 inches long, and you have to cut out an additional small area in the left front section to access the fuel line disconnects. I'm not going to get into the specifics, just give you my advice, and a stern warning that you'd better be damned careful if you try this.
You'll notice that the videos never show you the actual cutting of the panel. There's a reason for that: the amount of sparks is insane. I tried it with a dremel tool with reinforced cutting disks. It won't even come close to cutting through. The only other tool I had was a 4 1/2 inch angle grinder with a cutting disk. It worked alright, but I wish someone had been there to video me in the failing daylight, in my driveway in the back seat, with this powerful machine spitting enough sparks over the interior to catch my hair on fire. That was the scariest part: the sparks, and your going to have them with any cutting disk. If you can get an air nibbler that can handle that thickness of steel, do it. Now, I couldn't figure out how to get the gas out of the tank without a running fuel pump, because you cannot siphon it out. So I'm doing this with 7 gallons of gas in the tank. This was, without a doubt, one of the scariest experiences of my life. The cuts were rough because I was working alone, and the sparks were so bad I couldn't see my marks. Anyway, I got the panel cut out. There were a few places where I had actually gouged the fuel tank skin with the disk (You have 1 inch maximum clearance between the 2 surfaces) and that was scary. I highly recommend having a helper during this, or a machine with an adjustable cutting depth. Disconnecting the fuel lines is an absolute nightmare. There are 2 low pressure "return" lines that just have regular rubber hose connecting them, but there are also 2 high-pressure "out" lines that are in that little extra section that you have to cut, and they are insanely difficult to disconnect. I got the lines disconnected, but I couldn't figure out how to disconnect the electrical plug, so I just left it connected and worked around it. The wiring isn't very long and made things very difficult. The fuel pump/sender assembly is about 2 feet long and is a nightmare of wiring and hoses. The actual pump is on the very bottom. I found that the plastic electrical plug that connects to the pump was completely charred and crumbled into nothing when I touched it. The last few inches of wire going to the pump were melted and missing. I don't know how that could happen in the middle of a fuel tank, but it did. So, I had to cut out the electrical harness from the assembly, repair and solder it directly to the new OEM pump, and patch it back into the assembly. Now, if you think getting the pump out is fun, try putting it back in. It doesn't want to go back in. It took me a solid 30 minutes of twisting the assembly, scraping steel on steel with gallons of fuel staring me in my face, to get it back in. The sending unit float is a big part of the problem. Anyway, I got it in and locked it down with the 5 nuts. Connecting the hoses is a little easier, but not by much.
The next scary part was turning the key and hoping the pump didn't spark and blow me away. You can bet I made sure the seat was all the way back so I could roll out and a fire extinguisher right outside.
The car started right up. There were no leaks from the hose connections. The next day, I got a nice piece of steel sheet metal from Home Depot and cut it to size to cover the opening. You have to (or should) drill holes to mount this with gasket sealer, and you have to be careful doing that too.
This is a lot of writing, but I wanted you to know what to expect. It works, but it's dangerous. I can't recommend it. If you try this, have help, lots of light, and above all take your time. I consider myself lucky, and I wouldn't do it again. The problem is, once you start, you are commited to doing it. Good luck.
:banghead:
I closed out that thread because I thought I had the car sold, but the deal soured and I ended up going through the procedure anyway just to get it running. I had no money to hire someone for the traditional method. If you are considering performing this procedure, PLEASE READ THIS THREAD!
First, there are a number of videos you can see on the internet that explain how to do this. They are quite informative. You have to remove the rear carpeting and trace lines to cut out a panel roughly 7 1/4 inches wide X 12 inches long, and you have to cut out an additional small area in the left front section to access the fuel line disconnects. I'm not going to get into the specifics, just give you my advice, and a stern warning that you'd better be damned careful if you try this.
You'll notice that the videos never show you the actual cutting of the panel. There's a reason for that: the amount of sparks is insane. I tried it with a dremel tool with reinforced cutting disks. It won't even come close to cutting through. The only other tool I had was a 4 1/2 inch angle grinder with a cutting disk. It worked alright, but I wish someone had been there to video me in the failing daylight, in my driveway in the back seat, with this powerful machine spitting enough sparks over the interior to catch my hair on fire. That was the scariest part: the sparks, and your going to have them with any cutting disk. If you can get an air nibbler that can handle that thickness of steel, do it. Now, I couldn't figure out how to get the gas out of the tank without a running fuel pump, because you cannot siphon it out. So I'm doing this with 7 gallons of gas in the tank. This was, without a doubt, one of the scariest experiences of my life. The cuts were rough because I was working alone, and the sparks were so bad I couldn't see my marks. Anyway, I got the panel cut out. There were a few places where I had actually gouged the fuel tank skin with the disk (You have 1 inch maximum clearance between the 2 surfaces) and that was scary. I highly recommend having a helper during this, or a machine with an adjustable cutting depth. Disconnecting the fuel lines is an absolute nightmare. There are 2 low pressure "return" lines that just have regular rubber hose connecting them, but there are also 2 high-pressure "out" lines that are in that little extra section that you have to cut, and they are insanely difficult to disconnect. I got the lines disconnected, but I couldn't figure out how to disconnect the electrical plug, so I just left it connected and worked around it. The wiring isn't very long and made things very difficult. The fuel pump/sender assembly is about 2 feet long and is a nightmare of wiring and hoses. The actual pump is on the very bottom. I found that the plastic electrical plug that connects to the pump was completely charred and crumbled into nothing when I touched it. The last few inches of wire going to the pump were melted and missing. I don't know how that could happen in the middle of a fuel tank, but it did. So, I had to cut out the electrical harness from the assembly, repair and solder it directly to the new OEM pump, and patch it back into the assembly. Now, if you think getting the pump out is fun, try putting it back in. It doesn't want to go back in. It took me a solid 30 minutes of twisting the assembly, scraping steel on steel with gallons of fuel staring me in my face, to get it back in. The sending unit float is a big part of the problem. Anyway, I got it in and locked it down with the 5 nuts. Connecting the hoses is a little easier, but not by much.
The next scary part was turning the key and hoping the pump didn't spark and blow me away. You can bet I made sure the seat was all the way back so I could roll out and a fire extinguisher right outside.
The car started right up. There were no leaks from the hose connections. The next day, I got a nice piece of steel sheet metal from Home Depot and cut it to size to cover the opening. You have to (or should) drill holes to mount this with gasket sealer, and you have to be careful doing that too.
This is a lot of writing, but I wanted you to know what to expect. It works, but it's dangerous. I can't recommend it. If you try this, have help, lots of light, and above all take your time. I consider myself lucky, and I wouldn't do it again. The problem is, once you start, you are commited to doing it. Good luck.
:banghead:
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