ok so i did the same thing you did where i cut the hole and everything. i got the fuel pump out and put a new one in. i plugged it in to the harness without putting it back in the fuel tank just to see iif the fuel pump turned on and it didnt. so i took it off the harness and hook it up to a tractor battery to know if there was a fault in the pump itself and it turned on fine. it has to be an elctrical thing somewhere please help

 

check the fuel pump relay or wire in your own relay to the ignition wire as a temp fix

 

I had the same issue- seems the ground wire from the pump goes to the sending unit WHICH HAS TO BE GROUNDED TO THE CAR BY INSTALLING IT. I did that and it 'whirred' fine!

 

So after many many years of driving... any "stress" cracks or other madness from doing and access hole?

 

Holy thread bump batman!

 

Haha yep. After reading all the smack talking I had to know if anyone really experienced and issues by cutting the access door.

 

No problems, worked great. No regrets

 

No issues at at all with the access door

 

Figured I might as well keep the tradition of this thread going.

Had a fuel pump replaced about 5 years ago and they did an access panel. Fast forward to now and I need to replace the pump again. After peeling everything back, the pic is what I found. They had glued the sheet metal down so much that it's completely mangled now, so I'll have to replace that. Also, notice the rubber hose sections. I've since read in several places (including here) that those aren't the best option so I'm considering replacing them with compression fittings.

When I disconnect those hoses, how much gas should I expect to come out? Really has no place to go and that's the thing that concerns me - gas all over the inside of the car.

Also, I thought I had read that 2 of those lines were 3/8" and 2 were 1/4". These all appear to be 3/8"?

 

I have no signs of stress cracks and Im on my second car with this mod done.Mind you I think the stress cracks will depend heavily on the rest of the chassis and how much power your putting down.

 

Why not keep this thread going.

I did the whole rubber hose thing when I did mine, But I put a bump on the ends of the pressure and return pipes for extra sealing. The pipes are two different sizes (dont remember what off the top of my head).

If you depressurize the system properly (pull fuel pump fuse and try to start the car) you will get only dribbles, if you don't depressurize you will have gas everywhere. My advice would be to get a fuel pressure gauge just to be safe and know for sure that you have drained all the pressure.

 

So sitting there idle for 5 years won't depressurize it?

 

Can you just depressurize on the fuel rail? I opened the gas cap and depressurized the rail and hardly nothing was there. I only had some dribbles as mention before when I cut the lines.

I've replaced my fuel pump on a 3 and 4th gen using this access panel method and it was way easier than dropping the tank. Do I regret it? No - I'm the only one who knows, it not like you can see the repair when it's under the carpet. My replacement pump fail in the 4th gen 5 months after and I was very happy I had the access panel.

Also I learned to buy only the best pumps and replace the fuel filter and stainer screen when you replace. Some pump manufacturers will not warranty them if you don't replace these other components.

I used rivets and brushable non-hardening sealant from Eastwood I had laying around. The rivets only took a few minutes to drill out when I need to get back in there. No biggie.

 

still a great thread...ttt (to the top)

 

Previous owners hack job...but it did allow me to change the pump in like 15 minutes start to finish.

I'm going to put a piece of metal over the entire hole and seam seal it in place

 

Thanks for the pictures!!😊

 

Someone should make a really great thread on how to jump off a bridge... Or how to DIY Brain Surgery! Or maybe... I don't know, cut a giant hole someplace else in the car where it doesn't need a giant hole?

It's funny how the folks stupid enough to take this shortcut are generally also stupid enough to cut corners and do it half assed.

 

*why an auto manufacturer needs to accomodate every possible part repalcement, forever, on all vehicles
I 100% agree with you!

 

GM never cared too much about making repairs difficult. I do so many fuel tank drops in an average month, I can't begin to count them. The cars with access hatches are nice, but then having liquid fuel inside the car when you're swapping a pump isn't awesome either. A drain pan right at the tank opening to catch the dribbling fuel is the best you can do. That and alot of rags. I've done so many GM tanks, probably in the hundreds. The high failure rate of GM's fuel tank pressure sensors makes tank drops common. Really, no tank drop on anything that's not old and rusty is that big of a deal.

I will say that the 3rd gen F-body is probably one of the worst, just because you have to get the rear exhaust completely out of the vehicle to not have it interfere. An air chisel with a tube cutting tip helps alot. Then you have to completely drop the rear axle, detaching everything but the trailing arms and torque arm. Doing the job in a parking lot, without a lift and no air would have to suck. A custom exhaust that comes apart easily just in front of the rear axle would help. Be sure to disconnect the speedo cable so you don't break the speedo drive against the torque arm, and disconnect the brake line from the body so you don't stretch the hose. I've done a couple dozen of this style I guess, between my own and the 3rd and 4th gens I've repaired for customers. The last one I did went pretty quick, in the shop on a lift with air. Of course, I don't use power tools on any collector car, including my own. Just one of my personal rules.

If you search, you'll find my solution to tank drops. I sumped my tank for hard cornering without fuel pressure drop off and have an Aeromotive external pump feeding the engine. It's a simple and bullet proof system. Replacing the pump, if I ever need to, will take about 20 minutes.
When I finish my exhaust, once the new rear axle is installed, I'll use slip joints with tabs and no clamps to attach the rear section so it will come out easily, in case I ever do need to pull the tank.

I'm sorry but I hate the idea of cutting up a floor pan to avoid dropping a fuel tank. Then again, I certainly can't criticize anyone for building their own car their own way. Look at my Frankenstein build. Just be clean and neat about it as much as you can. One thing though concerning the use of rubber hose on the fuel supply line. Be sure to use the high pressure fuel hose clamps. They have a screw and nut instead of the threaded band like a typical hose clamp and they clamp alot tighter. Use two clamps on each hose to tube connection.

 

This is the clamp to use when connecting high pressure hose to tube with or without barb. They are available in a few sizes. This one came from NAPA.

 

What type of snips where those? The green handle one - is that a right handed or something along those lines?

-sc-

 

Threads like this make me throw up a little. I can't believe there's this many lazy sods out there.

 

In my expert opinion, I find the best tool for this job is the McCulloch "Eager Beaver" 2300cc internal combustion saw. It makes the most highly precise and FAST cuts imaginable that make this job a true breeze. I wouldn't even try to do this job again with something as medieval as snips or a pneumatic shear. Best thing ever for splicing the cut fuel hardlines is push to connect fittings. I like to smear a little silly putty on the fittings just for belt and suspenders insurance, but I like to error on the side of caution. When it's done this way, with these tools, it's safer than the factory. I was talking to a few buddies who are engineers at GM, and they agree. They tell me it's how the General should had done it, had they not been controlled by the damn bean counters. Jokes on them, because I fixered that **** right up. Bitches.