CUTLASS 3 port fuel gage parts alert + Gas gage wonky- Prolly going to have to drop the tank on the 87

69hurstolds

Geezer
Supporting Member
Jan 2, 2006
5,641
113
So- the 87 442 has been exhibiting some strange fuel gage issues lately. Nothing major, but every now and again it flutters a bit toward FULL and then stabilizes out. I checked the ground and there's no way moisture could get to it, I don't think with all that Rusty Jones bullcrap on it, but then again, I can't rule out the top side of the tank. It sure is acting like a bad ground, intermittently. Not a hard job, but just a general PITA.

Also, the car doesn't move a whole lot as of Covid, so I have a sneaky suspicion, even with the Sta-bil fuel additive the old fuel that's in it is trashed. I have been keeping it mostly full, but then, I haven't put new gas in it for over a year, heck, maybe longer. Starts and runs ok, but I've been a bad car parent lately. Fresh gas sure ain't going to hurt things.

In preparation for the tank drop, I'm going to, at a minimum, replace the sock and the sender O-ring and retainer metal ring with GM parts, obviously. I do have a few complete Delco senders in the box if I need to use one, but if it doesn't need replacing, I'm not going to replace it. I have the stuff in my stash but went ahead and ordered some replacements anyway.

The plan is to drop the tank, see what's up with the sender- could be a dirty rheostat, bad ground, or bad sender connector on the top of the tank, or worst case a bad sender altogether. I don't know for sure. When it goes back together, run a couple of Lucas fuel system cleaner bottles through and then change the fuel filter. That's the plan.

When I drop it I'll be able to check it and see. I can clean the sender rheostat and check all the wiring connections while I'm in there, inspect the tank for debris/rust, and any other mung that is hanging out in there. I'll likely clean the tank while it's out as a might-as-well.

Just to let you know, while the ring and gaskets are readily available, the sending units are not. There are aftermarket ones from Dorman and such, but the Delco ones are HTF. And worse yet, the sock strainers used to just fall out of the sky. Now they're discontinued and very hard to find now. I did manage to scare one up from gmpartsgiant.com though. So we'll see.

(carbureted) P/N's you may need if you decide to do yours someday-
25001613 - 3 port sending unit in tank. 25001612 is the 2 port unit. These comes with the sock and ground wiring pre-assembled.
3893116 superseded to 22515965 - rubber o-ring gasket for sealing sending unit to tank. They're 12.81 list price from GM!!! You can stop by a parts store and check their EPDM O-rings and match one up for a buck or two, I'm betting if strapped for cash. I'm too lazy to do all that, though. Lazy has a price. Newer ones have three tabs on the inner side for alignment assist, but you don't have to have those.
25124032- cam locking ring for sending unit. Found one for a couple bucks on ebay under a superseded number.
ACDelco #TS1000 aka GM#5651702 - Filter, sending unit. This is the new sock.

And if you need other crap for an 84-88 G47 Cutlass-
22525300 - gas cap, no handle, flat top plastic
22531616- Need 2, Nut, Front fuel tank strap bolt
11508331- need 2, Bolt, Front fuel tank strap
11508301- need 2, Bolt, REAR fuel tank strap
11500760- need 2, Nut, REAR fuel tank strap bolt
557935- Need 2, Strap, Fuel Tank
22510103- Tank, Fuel, G-47, carbureted

All in all, without the sender, I'm replacing everything I anticipate for about $35.00. If I need to use the new sender unit...yikes. It was $43.55 list back in 1987. ($102.65 in today's dollars)
 
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84 W40

Master Mechanic
Dec 9, 2009
417
93
Since you have all the parts you need your head of the game. I had replaced a sender unit 6 years ago for a friend with a 86 442 that had a similar issue your having.
The ground wire checked ok and it did have some rust on it cleaned it still ok. So I had him purchase a new sending unit before dropping the tank don't remember what brand it was but its still working. Pulled the original unit out did some testing and found two problems, the float would stick in the full or half full position never seen that but anything is possible, when testing the sender with an OHM meter it was working fine until I touched the metal shunt wire that has a plastic sleeving that connects to the rheostat to the plate that the wire connects too. It would start reading higher than normal, bad connection do to some rust. I do still have that sending unit and will take a picture of it.
 

84 W40

Master Mechanic
Dec 9, 2009
417
93
I did find that sender unit in a box that the new one came in. It was replaced with a Spectra FG08A.
The circle area was the problem, you can see rust around the push lock washer.
20210709_210952.jpg
 
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69hurstolds

Geezer
Supporting Member
Thread starter
Jan 2, 2006
5,641
113
Thanks for the tips.

Interestingly, someone else told me to check that push nut for corrosion as well. I'll definitely be posting up whatever issues I find. I have the replacement parts as necessary, so I'm pretty confident at some point, throwing enough money/parts at it, I can fix it. If all that checks out, it's probably not a bad thing cleaning out the tank after 34 years, but even if I have to go into the gage panel, I got some NOS gage pods for it if I need them. Still smells like a ground issue, but we shall see.
 
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