1986 Parisienne Wagon Sending Unit ??

Hi Guys,
What is the OEM part number for my '86 Parisienne Wagon sending unit?
Also...Are all sending units for '77-90 full size GM wagons the same part?
A while ago I order what was supposed to be the correct sending unit for my wagon from Rockauto, but they sent me the unit for the sedan, completely different.
Any help would be appreciated.
Thanks, Wayne

 

What type of sending unit?
What engine?

 

Sorry about that... It is the fuel tank sending unit, 307 Olds engine. I installed a beautiful replacement tank, actually made in Canada like the car, but my sending unit is in bad shape, so I definately need a new one or a nice rust free used one.
Thanks.

 

Instead of starting a whole new thread, I'm bringing this one back out of hibernation, since it directly relates to my situation...

MY gas gauge is not reading correctly anymore, and I'd like to attempt replacement of the sending unit myself, to avoid a HUGE labor bill.

I've located on Rock Auto what appears to be the correct unit, for MY Pontiac Safari -
Spectra Premium, # FG14B (or #25002212) - it's specified FOR a wagon, with AC. $33.79 .

(As a method of double-checking, I also looked up a sending unit for an '81 Caprice wagon with a 305 V8 - search returned the same exact part, which is what I suspected.)

I have not ordered it yet.

I've never done this job before......
What I'd like to know is tips and tricks on how to drop the tank and do the job?
Other than a new fuel filter, will I need any additional parts?
I also plan to clean the inside of the tank while it's down.
I plan to have the tank as empty as possible before I drop it - maybe only a gallon or so.

 

Less gas is nice. Have a charged garden hose with fog sprayer set up while you're working on it, JIC. Otherwise, it should be light enough for you to yard it out yourself using a floor jack and a board or two. An extra pair of hands helps, but should not be necessary.

 

Tentative plan in my head is to run it as low as possible, fuel-wise. Then....
- Back it onto my steel ramps to get the back end as high as I can.
- Loosen up the straps
- Get the floor jack and board set up - might even figure out a way to attach the board to the puck on the jack
- Get all the connections disconnected.. (Which brings up a good point. Do I have to disconnect the filler pipe at the fuel door end on the left quarter? I would assume so.....)

Not sure how much of a help the jack is going to be, since the tank is up inside the left quarter and not 'flat', like a sedan's tank would be.

 

I am not familiar with your setup, but most of the time you have to be able to lower the tank a little bit to disconnect the fuel lines and fill port. At that point it is nice to have the floor jack underneath it to support it. It just needs to be able to support the weight. They can be a bit awkward to handle even when they are mostly empty. Shouldn't be an issue with just one person.

Only other thing I might order just to have and they are cheap is a new lock ring and o-ring/gasket. It has been in there for almost 40 years. It might be fine, or not. Sometimes the lock rings are stubborn coming out so it is nice to have a new one at the ready.
https://www.rockauto.com/en/catalog...,1248780,fuel+&+air,fuel+tank+lock+ring,10325

 

Have you done the usual troubleshooting to rule out other, less-of-a-hassle-to-repair, possibilities? Exactly how is the gauge not reading correctly?

And just to verify, you have an '81 Pontiac Safari?

It is? I thought this was only true for the clamshell wagons. If yours is an '81, isn't the tank under the rear floor, pretty much like a sedan? I was looking at the rockauto site just now, and here's the replacement tank they show for an '81 Catalina wagon. The filler neck is on the left rear fender, but the tank itself is flat and underneath.

 

I think jaunty75 is right, the tanks on these cars were redesigned to be in between the frame legs in 1977 compared to in the quarter like the 1976 and earlier cars. That said, get as much gas out of the tank as possible. If you're competent or skilled you can jack the car up, pull the fuel feed line off of the fuel pump at the front, and let it gravity siphon out as well (these cars will drain practically their entire tanks like this).

After that, it's just loosening the straps and lowering the tank.

You should be able to electrically check out the sending unit and the ground strap using a multimeter without having to drop the tank though if you haven't already done so.

 

OK - I'm wrong on the tank location then....... I was figuring that since the rear-facing third seat footwell is there, then the tank had to be somewhere else. I guess it's actually right underneath the third seat bottom cushion then (but on the outside of the car....)

As to the diagnosis - already got that from my mechanic when I ran out of gas a few months ago and thought it was a mechanical problem, since the gauge wasn't on 'empty'. Cost me $100 to find out I was out of gas, and shop told me a sending unit was hard to find, and expensive to replace, so they didn't really want to do the job then. OK with me - I think I can handle it.

 

The reason the tank was in the left rear fender on the clamshell wagons was because the descending tailgate took up the space under the rear floor where the tank normally would have been located.

 

Not that you're required to, but you still haven't answered the most basic question. Exactly what DOES the fuel gauge do that tells you that the sending unit is the problem? When you fill the tank, where does the needle point? What did the shop do to determine that the sending unit is the problem? From what you say, it sounds like the shop wanted to get rid of you as they didn't want to do the job, so how can you trust anything they say? There are things that can cause the gauge to display faulty readings that don't require replacement of the sending unit to fix.

 

The gas gauge had been reading fine all the time I have owned the wagon. Usually got gas when it got real close to the last line. I did run out once, shortly after getting the wagon, so I assumed it to be accurate then. On this latest incident, I'd say the needle was about halfway between 'E' and 1/4 when I ran out, so I'm assuming it has something to do with the float. And if I have to drop the tank to perform whatever 'fix' is needed on the float, I might as well just replace the whole unit for $34... The needle does seem to work properly from 'Full' down to about the 1/4 area, after that, I don't trust it.

 

Dropping the tank is pretty straight forward. You got the right idea. Little gas as possible. Get the jack up there and remove the straps and slowly ease it down, disconnecting filler tube and evap. Tubes and the electric connection as you go. Slow and steady. And keep your mouth closed. Might just need to clean up the contacts from the float to the unit? Especially since you mentioned you never let it get that empty? Kev. Has good advice about getting a new ring for the tank. On newer vehicles that only sell a pump assembly for $120 they are nice enough to include a new ring. Now back to you Wayne. Sorry, I have no idea where to find one but I think someone else was on the hunt for the same and had to visit the yard? Good luck. Maybe a post in the classified.

 

Thank you for your answer. All I gotta say is, boy oh boy, you are demanding. These gauges were never the paragons of accuracy when new. The fact that you could trust it down to the E line was a testament to its unusual accuracy. The fact that you ran out of gas once when it was reading 1/8 is hardly a reason to condemn it. As long as it reads full when you fill it, how about just filling the tank when it gets to 1/4, instead of going to hell and back to drop the tank and replace the sending unit? I'd say the odds are no better than 50-50 that your new sending unit will provide any greater accuracy than your current one. You may go through all the trouble of replacement only to discover that the tanks runs dry when the gauge reads 1/8 just like it did before.

I've had occasion to drop two gas tanks in my life, once on my '67 Delta 88 back in 2009 and the other more recently on my '78 Toronado. In the former case, it was to actually replace the sending unit, which wasn't working at all. In the latter case, it was to replace the tank itself, which was rusty and thin in spots, and since I had the tank down, anyway, I put in a new sending unit. The two experiences went off ok, but both have told me that dropping fuel tanks is not something I want to do in my driveway on a regular basis.

If I were you, I'd forget about replacing the sending unit, I'd fill the tank when it gets to 1/4, and I'd get on with my life.