Write-Up: Fuel Pump/Tank Sending Unit Replacement

thanks for the response but according to my gmp service manual
the riv have a different tanks with .6 gallons more than aurora
riv - 76 liter
olds - 73.4 liter

I just want a spare tank on hand to replace mine if poking holes goes badly !

LARRY70GS wrote:

deekster_caddy wrote:

LARRY70GS wrote:

Replacing the tank is a big job. A friend of mine used 4 stainless self tapping screws and washers to hold the pump ring down. he used some sealer, and screwed them into the plastic tank.

great idea. What's the worst you can do - ruin the tank?

Worked like a charm for my friend. In fact he sold the car to a member on this board. Forget who it is. Car was from Monroe, CT, and was black. I want to say it is DEMonte1997 , but I'm not sure.

You are correct, Larry. I bought that car from Bob and after a few years sold it to DeMonte1997. Bob did the repair and it never leaked.

71gsx455-4spd wrote:

LARRY70GS wrote:

deekster_caddy wrote:

LARRY70GS wrote:

Replacing the tank is a big job. A friend of mine used 4 stainless self tapping screws and washers to hold the pump ring down. he used some sealer, and screwed them into the plastic tank.

great idea. What's the worst you can do - ruin the tank?

Worked like a charm for my friend. In fact he sold the car to a member on this board. Forget who it is. Car was from Monroe, CT, and was black. I want to say it is DEMonte1997 , but I'm not sure.

You are correct, Larry. I bought that car from Bob and after a few years sold it to DeMonte1997. Bob did the repair and it never leaked.

Maybe we can get DeMonte1997 to unbolt the inspection cover and take a picture of the repair. A picture is worth a thousand words, and at least some of us will be faced with this fuel tank problem at some point.

I PM'd DeMonte1997 and asked him to look in here.

Taking the inspection cover off now...

Some info on the fuel tank (pic of tank removed) and capacity findings can be found here:

https://rivperformance.editboard.com/t1760-the-gas-tank-fuel-capacity

On second thought...

I'm not sure how the inspection cover is usually configured. This one has 5 bolts. Those are 7mm and come out easy enough. However, it appears the cover itself was RTV'd to the trunk base to form a gasket. It doesn't want to budge. Is this typical? It could be double sided tape... doesn't seem like a normal rubber gasket judging by how it does not give no matter how hard I pull on it.

If someone can chime in in the next hour or so, that would be fantastic. I'll need to button this sucker back up in a bit but I'd like to try and make a final attempt at getting the pics prior.

The cover should not be sealed to the floor. A flat screw driver should peel it right up. There are some pics on page 6.

I think mine had some soft sealer, but it came off. Just have to pry a bit.

I'm not sure what went on with this cover but someone thought it would be prudent to goop it to the trunk. :/ The cover looks like it was pretty warped and then somewhat hammered it flat. Still looks screwed up to me. That might be why it was RTV'd. Not sure if that is necessary..

In short, it would take a large effort to get this damn thing off.

I've played with soft sealer on the inner door insulation and that wasn't any trouble. This stuff does not want to budge.

Oh Well, thanks for trying.

I don't own a Riviera, but I've been considering purchasing one. Is it as simple as lifting up the carpeting in the trunk and looking around the fuel pump to see if that ring is rusted out, or is it more hidden?

Just trying to educate myself on model specific things to watch out for when I'm looking them over.

Yoss wrote:

I don't own a Riviera, but I've been considering purchasing one. Is it as simple as lifting up the carpeting in the trunk and looking around the fuel pump to see if that ring is rusted out, or is it more hidden?

Just trying to educate myself on model specific things to watch out for when I'm looking them over.

Yes. The carpet and the wooden spare tire "cap" has to come out in order to see it. AND, there is an access cap with about eight 7mm screws that also has to be removed.
As for the gas tank, it's not so easy to replace. They damn near built the entire rear suspension around the tank

That's what I hear. I may try to do this as a project now, though I've never 'dropped' a rear suspension before. My buddy found a few gas tanks, but doesn't have the time to give me on doing the job. I'm sure there's a youtube video somewhere probably, and he'll help me to the extent that he can. I figure it's worth a shot, as I love the car. There's nothing too complicated he says, just the probability of alot of rusted bolts - nothing a hacksaw and torch can't handle. Let's see... a torch and a gas tank - doesn't sound like a good combination!

Thanks to all for your input.

Mike

taking a dinner break now..

My lock ring is rusted bad and will not budge. I am trying to tap it with a screw driver and hammer but have only gotten it to move maybe 1mm. It's on there REAL tight and not going anywhere fast.

I just did some searching and there is a tool - a fuel sender spanner wrench J 39765 to get the ring off?

Do i need that or is mine stuck on there unusually well?

Bout to finish dinner and go back out to beat the crap out this thing.

charlieRobinson wrote:

Do i need that or is mine stuck on there unusually well?

Unusually well. Mine came off last year without any real issues. Some just get STUCK.

Took me longer than I thought and I literally had to beat the shit out of the ring but it finally gave up and I got the module out.

So I am about to rig the new pump and I am reading this tutorial from intense (thanks for linking me, psycho) and they dont install the new sock on the newpump Why delete the pump filter?

step7
http://www.intense-racing.com/walbroinstall.shtml

huh. that's weird.  When I did mine I left it on. I had to sort of jam in in, but its been working fine for years.  I guess the theory is no gas should be able to get into the canister without going through the module filter anyway.

If it helps here's the series 1 writeup:
rivperformance.editboard.com/t2918-write-up-walbro-255-lph-fuel-pump-series-i

Its the same process, just no little brass outlet to keep the canister full at all times.

But you can see what crap still gets in the canister.

well, mission complete.. for now at least.

Started it back up and took it for a test drive. Everything seems OK.

I used the stock sleeve with the AEM filter and rubber cap. It fit perfectly.

There was a small black box between the pump and the power lines. The intense write up shows this being reinstalled. I got a new fuel level sensor cause mine was toast and it did not have the black box on it's harness.

I chose to keep the black box and only use the leads to the sensor from the new sensor harness.

bout to deplete all the fuel left in the tank and fill 100% E85 and load this tune.
Got a few fuel filters on hand after i push some corn through the system.

We'll see what happens next..

My tank shows full at all times after I put the car back together. That was odd, I wonder if the battery dying on me a few times and jump starting it might have caused it. Luckily I saved my old sending unit with the bad fuel pump so I'm gonna try and make 1 outta 2 work. I'm hoping its not my gauge that's out

I replaced the fuel level sensor when I did my pump last week. I have been driving over a year with a bad sensor going by mileage as and indicator when to refuel.

It's awesome actually having it work now. It's the little things, ya know?

here's some pix n shit of my install from last weekend before i lapse and never say anything about it again.
The most difficult part of the entire job was getting that lock ring off. That sucked.
Beat the shit out of it with a hammer and chisel for 2 hours straight. I dont mean some taps here and there. I was unleashing rage into the back of the chisel. Had to even soak it in pb blast and let it sit for a minute.


Once I got the module out, the rest of the job was fun.

Anyone know what the black box is in the power line to pump? Didnt look like there was a way to open it or disconnect it. My replacement fuel level gauge harness did not have the box on it but the intense fuel pump write up showed them leaving it on so I left it how it was.

The AEM pump fit perfectly into the stock sleeve and into the module. I used the stock main line too. I followed the intense write up and pried the nipple off the old pump. (that was the 2nd suckiest part of this job) and ran the venturi line back to the pump.


I had a new gasket and lock ring on hand thanks to the wisdom of the internet and many posts warning anyone about to do this job to have them ready.
The new gasket wasnt the same as the old but seems to be just as if not more effective.
got it off rockauto


on 93 I would get about ~75 miles on my first quarter tank. I am currently at the quarter mark with  ~70 miles on E85. Time and tuning will tell how the MPGs ultimately play out but I absolutely love it so far. The smel,l the power, the price. People say it's 30% more consumption and I started my tune that way but my trims were crazy rich. I pulled it back and increased cylinder gain by ~24%. Getting great AFRs and fuel trims and 0KR, of course.

corn for life

charlieRobinson wrote:

I replaced the fuel level sensor when I did my pump last week. I have been driving over a year with a bad sensor going by mileage as and indicator when to refuel.

It's awesome actually having it work now. It's the little things, ya know?

Yo Charlie where did you get the part. I wanna order a new one. I just took out my fuel pump sending unit. My tank shows full all the time. I wish!

got if off ebay. A simple search should yield results.

Gfys- do a simple search on that