I’ve had my ‘50 Rocket 88 cabrio for about 16 months now. After 6 months or so of ownership the fuel gauge started reading irratically. Eventually it just stayed on empty. Checked the terminals on the gauge and all seemed OK. Today I dropped the fuel tank and took out the sender unit and the problem showed itself:

Crack in the float on the left hand side.

I cleaned the unit up and could see it more clearly.



I drilled a 1mm hole at each end of the crack to stop it getting worse having decided to solder the float”




However, no point in soldering the float to then find the resistor in the sender is not good so tested that:



3.7 Ohms in the empty position


33.1 Ohms in the full position

I’m sure I read on a post that the variation for my vehicle should be 30 Ohms (Could someone chime in and confirm please) in which case all looks good. Tomorrow I will solder the float and update.

 

Yes, 0-30 ohms for the sender. After you solder it make sure its water tight and floats.

 

OldsMcDonald, that is some nice work!

A 75 year old American Olds runnin all over the UK! Bet you get some curious looks.

 

Here it is soldered up - not pretty but waterproof so good to go.




I do get some interesting looks - usually very appreciative. I definitely puts smiles on peoples faces and the young lady that I took to her prom couldn’t stop smiling!

 

Let us know how the fuel gauge works when you reassemble it.

Smiles per gallon.

 

How did you test it? If it was me, knowing what a PITA it is to get a tank out, I would get a quart (liter) can and fill it 3/4 full of paint thinner or similar and submerse that float completely overnight to make sure it isn’t taking on any fluid.

 

Thanks OLdGreenPaint, that’s a really good idea. Held it under water for a couple of minutes with no bubbles but I’ll give it 24 hours in a bucket of thinners and see what happens.
The tank was really easy to remove - I should add that, although I have no history, the car had 1,200 miles on when I bought it 16 months ago and now has about 2,000 on it. The underneath is near immaculate, no rust - not even on the bolts so either the mileage is genuine or it has had a complete renovation. I don’t know what colour the tank would have been originally but my tank is silver and has no stone chips or rust.
My next problem is the charging system. Rebuilt generator, replacement voltage regulator but it doesn’t appear to be charging. Picking up a new battery at the weekend and then i will start investigating it I’m not skilled in electrics.
Picture of the outside”

 

That car is just a real piece of artwork. I was hoping I would see a picture. Thanks!

The lightning rod on the end of front fender is so cool.

 

Had to stop by again this morning and just look at that car again. What a BEAUTY!

 

That's a parking aid, not a lightning rod. To the op, before setting off the parts cannon, get a meter out and measure the battery voltage both with the engine off and running.

 

I followed OGP’s advice and sure enough 16 hours submerged in thinners identified another crack as in the photo below:



Once again I soldered it up:



And once again it took on liquid after soaking. I could have gone on soldering but then I had a bit of an epiphany - due to the wife finding this available in the UK for £20:



The white section is some kind of sealed foam so will not suffer from pin holes and it fits the sender unit perfect - as below. It’s from a Ford V8 apparently. Checked resistance and exactly the same so it gets fitted tomorrow with the new battery.

 

Nice work Olds Mac. Water has a lot of surface tension and gasoline and paint thinners will get into cracks that water sometimes will not. I just worked on the sender in my 72 Cutlass and it is a mean ornery job to remove the tank and work on it. Easily a full day if you have to drain the tank. So since I don’t know the tank setup for your car, I just didn’t want you to have to do it twice. Sounds like the tank is easier to get to than my car?

Also, regarding lightning rod, no offense intended. Just easier for me to describe it that way rather than saying That chrome rod thingy attached to front bumper. It does look a lot like the rods on top of Iowa barns though.

So you are driving and parking with the left side next to curb? That parking aid doesn’t work so well in the UK then? Just look out your window instead?

Glad you found a good way to fix it.

 

Make sure that it is compatible with ethanol fuel before you put it into the tank.

 

Thank you for your advice - really helpful. No offence taken on the rod - I’ve actually taken it off - I was never going to use, mainly because I’m too short to see it As you say, it’s on the wrong side for the UK. I’m careful and leave plenty of clearance between the tyre and the kerb.

 

That is an excellent suggestion - thank you. I’ll soak it in fuel before I put it in the tank.

 

Off topic, but I have to ask, do you have ethanol blends in the UK?

 

We get the choice of two - one with 5% ethanol and one with 10%. I use the 5% (it seems OK with the new float) and put in a lead replacement additive. My 48 Plymouth had hardened valves but I don’t think the Oldsmobile does?

Fuel tank goes back in today

 

Fuel tank already to go in and tested once again just to make sure:




Correct fuel gauge reading:



Now to look at the charging. I get 6.18v at the (brand new) battery with and without the engine running. I have it on a smart charger at the moment.

 

I just had to chime in and comment on your car.It's gorgeous.Love it.