Fuel sender

[mlapp]

I have what I believe is a bad fuel sender on 2 cars ('77 and '85), as the fuel guage only works intermittently on both cars. Is there a fix for the sender, or is replacement the only answer?

mlapp@lapptech.com

[ipacketeer]

I remember reading a post on the subject, some one had written about how to clean the contacts on the sender, if you do a search you may come up with and answer. Good luck.

[Howard M]

Very easy to remove and service by carefully cleaning the contact wires. Remove the sender from the tank and remove the nut at the bottom of the can. Slide can away and the service to be done will be obvious.

[notmytarga]

I cleaned mine up five years ago and never got a reliable level indication. The float bottomed out on the contact for the little empty warning light - when that was only off during left turns I knew I was closest to empty. My wires were clean and intact but still the gauge read inconsistently. I think I remember using a multimeter to asses the smoothness of the resistence feedback - I remember it was smoother than the gauge told me.

So what did I do - I waited five years and recently bought a new sender. Five minute install. It works better. But I did have problems with it after manipulating wires around the ignition switch - then it improved. This tells me two things - I may have a good used sender and that the gauge needs to be checked for good electrical contacts, probably a grounding issue. Opening the sender up and cleaning it up is easy and worthwhile as well.

[Long Nose]

I actually had the same question, since my fuel guage doesn't work at all.

I was not sure if it was the sender or the guage. Is there a way you can tell if the sender is OK? Would the guage work intermittently if the sender was haywire?

[joefrantz]

I did some work on my fuel sender recently and thought it would be a good add-on for this thread.

I’m re-assembling my car after a fairly lengthy restoration. When I pulled the fuel sender out of storage I noticed a ding in the tube. I wanted to be sure that the ding wouldn’t impede the float movement, so I disassembled the sender to check things out.




Those two black things in the first picture used to be the float. It is usually one piece and encloses the trolley that runs along the wires and rod above it in the picture. I’m not sure if the ding and the broken float were caused by the same thing, but the ding is definitely deep enough to get in the way, and the float is history.

I bought a used sender, but since the cover plate on my original was in nicer condition and carries a date ( 2.73) appropriate to the car, I wanted to keep the main part of my sender and swap in the float and undamaged tube from the replacement.



Easier said than done. I couldn’t figure out how to separate the float from the trolley. The float actually looks like it’s cast around the trolley. Since I already had one broken float, I didn’t want to force the issue, so to speak. I decided to swap my original cover plate onto the new sender.

The cover plate is held in place by three posts molded into the white plastic disk under it. The posts are “mushroomed” to hold it in place like a rivet. I remember attaching wheels to plastic model planes as a kid using a similar technique. Put the wheel on the axle and hit it with a hot screw driver to mushroom the axle.

There is a lot of excess play in the posts, so by carefully grinding off the mushrooms with a Dremel drum sanding bit, I could remove the cover plate from the replacement sender, and substitute the original dated one from my car. There is still plenty of post left to “re-mushroom” it with a hot screwdriver.



After cleaning everything up, it’s tough to detect the change. Notice the 2.73 date on the left.



Back in the new tube.



Installed in the tank.

[RoninLB]