F**ck#n fuel pump (again)

There is really never a good time or place to have a car quit and leave you stranded........ So, Friday the 13th, so far the hottest day of the year......I needed to chase batteries for my work truck in my car and it stranded me in front of the parts store DOH!.....It was a very long day.........
The car had given me zero warning and would crank fine but not start....Got it dragged home and checked fuel pressure (zero) with the pump hotwired, so at least I know what to fix......While the tank is out, I have cut a hole in the top of the floor "dome" above the module and the floor dome I cut out of the other car fits over the dome like a glove! I also traced a leak I have when full to the solder joint around the vapor cannister metal line where it goes through the module plate and slopped a tablespoon of Marine -Tex epoxy around it.......I'll post pictures later in the appropriate forum when I get a chance...

Cool, problem solved

At least you knew where to look and how to fix it. the joys of the old car hobby.

Hopefully the parts store that you were in front of, gave you a good deal on a new pump.

Pictures!



The crack around the vent pipe had a lot of fuel staining around it, so I filled around it with white marine-tex epoxy...



this shows the hole I cut from the top of the dome, leaving side walls that position and fit the cover piece I robbed from a donor car...

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look how nice the cover piece sets over the hole and lays flat.... It can't slide around because the walls around the hole fit inside it like a glove...




I snatched all the door seals from the donor wagon and cut and fitted this piece clipped around the inside of the hole..





Look how nicely the hole fits the module with plenty of work space to r&r the pump...Also notice the compression fittings installed in the lines that eliminate the need for a bigger hole...





with the hole cut in the carpet, the seal sticks up far enough to seal to the inside of the cover piece with it st on top of the carpet..... The seat foam holds the cover down snugly enough to seal and there are no fumes..... How do I know?..... Well..... There is still a leak on top of the tank near the left strap rail pocket when the tank is full... I can't smell it inside the car with the doors shut, but I can smell it when I open the door....

desert cars,... gotta love workin on them

Nice Job. Great pics. Tanks for posting them.

Really nice looking job!

One thing I was surprised to see once the tank was in......The tank is pushed up tight against the floor with basically no "air gap" anywhere except in the top of that dome...... Cutting of a hole should not be attempted with the tank in the car

very nice piece of work.

Very nice job on the access panel to the fuel pump! I mean that!
As I‘m just finishing up replacing the pump in my wagon, I’m wondering how it’s possible to get the pump out of the tank with the tank up against the cargo floor. I’d also looked at a post, perhaps six months ago, where the poster showed the correct pattern to make a cutaway under the rear seat to accomplish the same thing.

I was surprised how difficult it is to remove and replace the pump with the tank setting on the bench! To just remove the old one, I had to cut the old and hardened transfer tube (from the pump to the line-out), and then really twist and pull to get the float through the hole. It just makes it, with considerable pressure! Putting the new one in wasn’t much easier, although the transfer line could be pushed to the side, but the float still had to be physically “shoved” though the opening.

I’m wondering how this could work out with the tank up against the floor, with three 18” long steel fuel lines attached to the pump, extending to the front of the tank?

Now that I've looked at the photos, a little more closely, I see the "key " to the whole concept! I originally had not noticed the compression unions, which should make the pump change possible. Great idea! It certainly beats the 'quick disconnect" GM fittings!
I'm thinking that the issue with the electrical harness fitting so tightly between the tank and floor, could be solved by loosening the front strap anchors by 5 to 7 turns or more (they are long bolts) to lower the tank slightly.

paart wrote:

I'm thinking that the issue with the electrical harness fitting so tightly between the tank and floor, could be solved by loosening the front strap anchors by 5 to 7 turns or more (they are long bolts) to lower the tank slightly.

OUCH!-- You just caught something I missed...... Yes, the wiring harness is pressed between the floor and the tank, so I'm gonna hafta put a plug/socket up on top so it will unplug up there as well..... As it is now, I have to take the tank down one more time to find the leak and maybe replace the tank (I have a spare)....

The other recipe for cutting an access hole would work fine if you don't want to use compression fittings on the metal lines, although I think the hole around the module needs to be wider and come back a bit farther like mine so that the pump and float can be twisted and finessed carefully through the opening....

I realize this has been around since last spring, but I thought I would add my 2 cents.

On the newer sender units, with the yellow plastic pump carrier, you can disconnect the float arm from the rheostat/potentiometer arm, and move the float closer to the pump. It facilitates removal from the tank. It is tight for reattaching it in the tank, but can be done.

The vent hose from the top of the tank to the filler neck can crack and leak. You will not see it unless the tank is full, and you have the tank removed from the car. The hose is an odd size (18mm), and you will not be able to find it on the weekend (ask me how I know). You can use a 3/4 inch (19mm) hose, but no one has it in cut lengths. You can not replace the hose with the tank in the car.

The TBI cars do not have the left exhaust pipe, and the tank can be dropped with the filler hose/neck attached. You must remove the gas cap, unbolt the filler neck from the filler door pocket, and remove the grounding strap. It will pull down with the tank. It will be difficult to get out from under the car unless you can raise it substantially. You can access the hoses better if you want to pull it out. Fuel spills are minimized as well.

Provided that you do not trap the wire harness, there is a channel for it that allows it to be pulled through until the connector catches at the intersection of the tank and body.

Thanks for your input, Fred!
One thing I've noticed after dropping the tanks on three of these TBI cars.......Previous mechanics had broken the plastic housing around the tank fill spout on three of these cars, probably by trying to pull the spout away from the tank without removing the four screws up on top.....I know everybody has their own ways, but I remove the fill spout and pull the surge tube (check ball tube) out of the tank and suck all the fuel out before dropping the tank ( the only way to suck the bottom half of the fuel out).... I have replaced that fill spout vent hose on one car, but it's good on mine.... I also thought my leak was going to be the cracked metal tube that I repaired with epoxy, but that did not turn out to be my leak.... When the weather gets cooler, I'm gonna drop the tank, pressurize it with air and soap check it for bubbles.... I know these tanks are unrepairable and that's why I kept the tank from the donor car.....

I love this thread I am in the process of doing the same thing to my 94 RMW, could you please provide where you bought the compression fittings and what sizes and part numbers, also did you extend the fuel lines to allow hook up to the compression fittings. I found some fittings on the internet made by Dorman are these the ones you used? What is the hole diameter you cut? Any info you can provide would be a great help! My tank is out its a perfect time to do this modification. This is the best procedure I have seen bravo! I have 2 long roofs a 94 RMW and a 92 OCC. I live in Tucson AZ and my RMW and OCC are rust free and a real joy to work on! Many thanks Joe

I just bought the compression fittings at a local industrial supply that sells all types of hydraulic plumbing.... I cut the metal lines as close to the module as I felt I could do and have enough line left on the module for the nuts and ferrels to work......I then took the cut and de-burred lines with me to the supply house to fit the ferrels to and determine what size.....The hole I cut in the dome above the module is pretty self explanatory. On the blue cover piece, I drew the same line as the dome cut with a sharpie, so others can see how far the existing sheetmetal goes into the cover piece....ABSOLUTELY DO NOT try to cut a hole with the tank in the car because it fits skin-to-skin against the bottom of the floor!
I'm pretty sure I have cracked a second gas tank, probably because I tightened the straps.... I'm guessing maybe the car has pinch nuts and I wasn't supposed to completely tighten the straps..... I'm going to hafta drop the tank AGAIN!....I'll probably try the JB Plastic weld stuff OR I may need another replacement tank....

Not quite sure I follow how you attached the compression fittingspump tubing. Did you cut off all the GM fitting that are folded onto the tubing? What did you do at the filter, and forward from there?

Have you had any leaks since. I'm about to replumb ALL the fuel lines, and am gathering notes.

I just cut the metal tubes close to the module so they could be did-assembled through the dome hole..... I still kept the full length of the tubes with the factory ends so that all the hoses are the factory stuff..... the compression fittings use two brass ferrels slid onto the tube on either side of the cut, then compressed by the two nuts....NO LEAKS!.......

Found my pics in this thread, which I had forgotten about......