Guest Stan Leslie Posted July 21, 2010 Share Posted July 21, 2010 Recently took Reatta out of storage for summer. Had parked car last fall with about 5/8 full tank with Sta-bil added. Decided to run tank down to low fuel before refilling to burn off most of the old fuel. After refilling, gage read about 3/4. Within a few minutes it read full. Stayed on full for about 140 miles, then dropped down to about 3/4, then down to about 1/2 in next 30-40 miles. Seems to be working normally below 3/4. I refilled and observed about the same (currently at 1/2). I assume corrosion is the culprit. Happen to talk to a 90 Reatta owner last week at MIS and he said his was permanently stuck on Full. Just curious, since I assume this in not an uncommon problem. Is the corrosion/sticking an issue with the float and float arm or is it an issue with only the sending unit rheostat being corroded? Any body have or had similar problem? I assume only real solution is dropping the tank. Link to comment Share on other sites More sharing options...
Jim Posted July 21, 2010 Share Posted July 21, 2010 Stan,It is a little common for Reattas that have been stored to have that problem. Just drive the car and the problem should go away. I experienced the same problem once myself. I bought a slightly damaged convertible that had been sitting for a while. I repaired it and drove it to the BCA meet in Plano TX. When I started out I had gauge problems but by the time I got home the gauge worked fine and the current owner has never had any more problems.Jim Link to comment Share on other sites More sharing options...
Guest Stan Leslie Posted July 21, 2010 Share Posted July 21, 2010 I will assume that repeated cycling is what may fix it, therefore maybe I will start refilling at 1/2 tank to speed up the process. Link to comment Share on other sites More sharing options...
Guest NEMO Posted July 21, 2010 Share Posted July 21, 2010 Always fill the car when it is no lower then half, It keeps fresh gas in there and you never know when the power is out due to a storm, gas pumps do not work. Link to comment Share on other sites More sharing options...
padgett Posted July 21, 2010 Share Posted July 21, 2010 Is common in any GM car that sits for a while. Keeping full helps. Link to comment Share on other sites More sharing options...
Barney Eaton Posted July 22, 2010 Share Posted July 22, 2010 I am not sure why or if the Reatta is more troublesome in this area than other cars. The unit in the tank is pretty simple (and fragile), there is a wrap of wire that a contact rides on as the float arm moves with the gas level. What probably happens.. the wire wrap is getting a film on it and until the float arm moves up and down enough to wipe it clean, you get a false reading..... which will usually be empty. The sending unit I last worked on did not have a problem with the coil or wire but a bad common connection at the pivit point of the wiper. That is a thin copper/brass part that was very brittle and it disentragated when we started working on it. That problem was easily solved with a piece of flexable wire soldered inplace.Maybe the solution is to rock the car while in storage .... this would cause the gas to move the float arm and keep the contacts clean. Link to comment Share on other sites More sharing options...
Vincent Vega Posted July 22, 2010 Share Posted July 22, 2010 I had a similar problem with my '97 Aurora. It was really annoying because of the DIC chiming in when the sending unit thought the gas was really low. Luckily they incorporated an access panel inside the trunk to remove the sender/pump without dropping the tank. The very fragile "fingers" on the sender had worn down and didn't maintain constant contact. Try a can of seafoam or something else to help clean up any gunk in there. The only other option is to drop the tank and inspect/R&R it. Link to comment Share on other sites More sharing options...
padgett Posted July 22, 2010 Share Posted July 22, 2010 I have always been surprised that GM used exposed windings and a wiper for the fuel level, near as I can tell the design dates back to the '30s. Rocking will not move it much, use and storing with a full tank is the only thing that keeps them working properly.Possibly draining completely and filling with nitrogen might work long term, suspect it is air and moisture that does it though varnish won't help. Link to comment Share on other sites More sharing options...
charlie1 Posted July 22, 2010 Share Posted July 22, 2010 Had mine replaced in 89 Riviera. Replaced fuel pump while tank was lowered. Used OEM pump. All is well! Link to comment Share on other sites More sharing options...
Guest Stan Leslie Posted July 22, 2010 Share Posted July 22, 2010 I will keep refilling the tank at 1/2 to speed up the cycling of the sending unit and see if it might cure itself as Jim Finn suggested. I reset the trip odo. at refill as backup for now. No access panel here. Dropping the tank is a pain but not that bad. However, if it comes to that, I will likely replace the fuel pump while it's down. Due to the weight of the float arm, I tend to think it is the wirewound resistor (sending unit) that is coated with something on the upper half. Will park it full next time, as I usually have. Link to comment Share on other sites More sharing options...
charlie1 Posted July 22, 2010 Share Posted July 22, 2010 Hope you do not have to drop tank. As info they replaced hoses while tank was lowered.Good Luck! Link to comment Share on other sites More sharing options...
padgett Posted July 23, 2010 Share Posted July 23, 2010 Picnic compared to Fiero - five hoses in the end of the tank & no way to siphon. Might think about adding a drain if you drop the tank. Link to comment Share on other sites More sharing options...
Vincent Vega Posted July 23, 2010 Share Posted July 23, 2010 Green connector under the hood will power the pump. Disconnect fuel line and direct to gas can. Jumper wire from connector to battery. Tank will drain. Link to comment Share on other sites More sharing options...
padgett Posted July 23, 2010 Share Posted July 23, 2010 I had been wondering about that technique. Do you measure the rate in GPM or GPH ? Link to comment Share on other sites More sharing options...
Vincent Vega Posted July 23, 2010 Share Posted July 23, 2010 It goes pretty fast. I don't know the flow rate. Worked quite well when I had to junk the '90 LeSabre with a full tank. Link to comment Share on other sites More sharing options...
Barney Eaton Posted July 23, 2010 Share Posted July 23, 2010 I attempted to take some better pictures of the in-tank gage parts.The tan part has the resistance coil that the wiper touches as the float goes up and down. Notice the condition, contamination etc on this part.The other shot is the gage showing the position of the float. Also note the tan part with the resistance coil mounts on the unit with two screws. It that part of your gage is bad, it is easy (once it is out of the tank) to replace it with one from another unit.Also note that the electrical connection is made by the spring that the screw goes through.There are lots of possible failure points on these units....it is supprising they even work. Link to comment Share on other sites More sharing options...
Guest Stan Leslie Posted July 23, 2010 Share Posted July 23, 2010 It does seem to be repairing itself. Today it started reading less than full after 125 miles - droped to between 3/4 and 7/8. Refilled at a little below 3/4. Registered one square below full for a few minutes then went to full. Maybe thre or four more fillups will do it. Link to comment Share on other sites More sharing options...
MJMBrooks Posted June 25, 2018 Share Posted June 25, 2018 Hi. I'm having similiar problems with a car that just came out of a twelve year storage. I dropped the tank, removed the sender to find that the plastic float arm has too much end play not allowing all contacts to touch their corresponding surfaces at the same time. It appears that the only way to access the contacts would be to remove the heat staked areas to allow removal and subsequent disassembly of the sender contact pieces. My question is, has anyone had success with attempting this or should I cannibalize another sender for it's mechanism such as a more commonly available new assembly? Link to comment Share on other sites More sharing options...
Barney Eaton Posted June 25, 2018 Share Posted June 25, 2018 Even if you find another unit to replace yours, you will need to remove/trim those plastic rivets. I just cut them off and use small screws in their place. Sometimes the problem is the wiper shown in the picture.......it is made of very thin brass...the leg sticking out on the right is the wiper that touches the winding to change the gage reading. It may need to be cleaned and bent (carefully) to make good contact. On each side of the post that is sticking up are spring wipers that go to ground. The thin wire I added (shown in this picture) is soldered to the copper base and the coiling of the wire is to allow the arm to move freely..... the other end of the wire is soldered to ground and that solve that contact problem Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now