I know I read this somewhere else in this forum, but now I can't find it. Anyway, here's my situation. The gauge used to work, although I don't know how accurate, but it used to move down as the car used up fuel. For the past 2 fill ups, it has stayed full for at least 100 miles, and I know that's bogus. The first time, I hit a pothole and the guage started to work again. This time, no such luck. I am sure its going to get to 1/4 tank and work, but I don't want to wait for that. What's the solution to this problem? Everything else in the cluster works fine

 

Your fuel pump and sending unit are all together in your fuel tank and easily lift out with the filler neck from the top at gas cap. You just disconnect battery first then remove the fuel lid and rubber splash boot to reveal the fuel lines and wire harnesses that need to be unhooked. Unhook them and remove the screws and lift the pump and sender unit with float out with the filler neck.


It sounds like your float is sticking because of the "pot hole" thing you spoke of. You may can just clean up and lubricate the float action and replace it. If that doesn't work, it may be time for a new pump and sender.

Good luck and let us know how you do.

 

Thanks! Which part gets the lube? I am assuming is the pivot where the float joins the rest of the assembly, correct?

 

That is correct and use a light penetrating petroleum based lube and work the arm back and forth to get it in. Then clean up any excess because the assembly is going back into your gasoline.

 

Do you have any recommendations for lube?

 

Well honestly, not really, but for that application I would think WD40 would be ok. Just make sure it's petrolleum based and I think you'll be ok.

 

I agree...also, make sure the float is not catching on the edge of the white plastic "housing"...probably it isn't, but worth checking while it is out...

 

I emailed you the tech article to repair your sending unit in MS Word format with pics.

The senders are outrageously priced, and 99% of them can be fixed.

Simple repair.

 

Here's the forum's tech tip on it.

Fuel sender

Which upon further review I see was written by Frizlefrak! Good job!

 

Thanks.....I'm still getting quite a few requests for the tech article with pics, so I need to get off my lazy butt and post the thread with pics again. Can't seem to locate it in the archives anymore. Plus I need to update it with the correct resistance values from the Helms.

When my sending unit went south, it stayed on full for the first 200 miles or so, then dropped immediately to about 1/4, where it would stay until the car quit running.

I was lucky enough to have Mike88Z51 teach me the procedure and suggest I write the article A $15 gasket and 1 hour later, and it works just fine. I gasp every time I see what a new sending unit costs. When you take one apart and see how simple they are, you will too.

 

I agree about the costs of the new units. I saw one in a catalog going for $479! Ridiculous. Used ones on eBay are starting at $200 as well. I'll pick up the gasket and a new boot, mine is cracked, and do the repair this weekend, right after I check to see if my heater control valve is shot (defroster problem).

By the way, has anyone installed that longer drain hose kit they sell? I am wondering if its worth picking up as well.

 

OK, I figured I'd share this.

I called the local Corvette guy near me looking for a new filler neck gasket in preparation for the repair. He asks me what was wrong, so I tell him that the gauge is stuck in the Full position until it gets low enough, blah, blah, blah. He tells me he sees this all the time and all I have to do is bend the float back a little bit toward the rear of the car and it will solve the problem. He mentioned that air gets trapped around or in the bladder in the tank and that's what the float gets stuck on. Has anyone heard this? Just curious.

 

I took mine apart yesterday, same basic problems. What I found is that there was a light corrosion on most everything in the tank, not rust but a light brown corrosion that wipes off fairly easily. Anyway there is a wiper arm that touches a wire resistor to transmit different resistance to the gage. When the float is up(tank full) the arm touches the resistor at maximum resistance. When the arm is down(empty tank) the arm touches the risistor near zero ohms. The arm and resistor where easily cleaned with a pencil eraser. There are two tiny wipers that keep the electrical contact as the arm and float move up and down and these along with the plate they contact need cleaning too. Be very carefull as these wipers are very delicate and easily bent and broken, I broke one last night trying to bend it back after I bent it. I still have one good wiper and I took a bit of the housing and bent it as a second wiper and even though its a rig when I siphon fuel out and into the tank it works. I figure if it goes bad then I'll worry about replacing it, after all it won't strand me on the road somewhere. If it goes bad the sender will send max resistance and the gage will read full so I'll know if it messes up.

On ebay you can find the whole assembly from $50 to $100. I called the dealer and they want over $1000

I don't see anywhere were this assembly would need any type of lubrication.....

 

We need to find out where we can purchase these sendors with the wiring windings on them. I took mine apart, and the wires had been broken. ?

I don't know how they go that way, but the contact that runs across the windings was clean and shiny, and I played with the little banana shaped piece of metal with the wires wraped around it, with no luck.

Does anyone know how to find these parts? I bet they would cost a whole whopping $3 or something cheap as water. There's nothing to it.

Thanks

D Moss

 

Hmmmm..I may be confusing it with the one om my S10 but If memory serves me (it's been a good while) mine had some crusty stuff where the metal float rod meets the plastic part that rotates. Thats what I cleaned and lubed on top of and down behind. Mine was sticky and I cleaned and loosened it up and made sure it moved freely and it has worked great since.

 

skateparkdave, sounds like the S-10 IS different.

The cheapest place I've found a new unit is at Ecklers and it comes with the filler but without the pump for around $360. I agree that we should be able to get just the sensor parts but I don't see anyone carrying them.

 

Would this be for a C5 as well? My husband bought me a C5 for xmas and on a 2 hour trip to north bay my fuel tank abruptly went to empty and the check guage illuminated with a low fuel message. We are trying Chevron gas and running some techron through it now and seeing if this will for go the problem if not I am trying to get a heads up on how to change out the right and left sending units as Chevy has quoted us about $500 for both. Thanks for any help you can give.

 

Sounds like there's a difference in design for the C5. On the C4 the gage reads full if there's no contact in the sender and you're reading empty. Also the C4 only has one sender in the center of the tank. It's easy to pull out of the C4 just expensive to get new parts. The C5 sounds very diifferent. $500 for both installed doesn't sound too bad...

 

I remember reading a reader's letter regarding the C5 gas gauge in this month's Corvette Fever. It might help.

 

Try a HALF QUART of:
A) ACETONE
B) Toluene
C) Paint Thinner
in a full tank of gas.

There's a good chance this will fix it. Did mine.

If not then you can take it out and clean the sending unit as described above.

Shell had some gas for awhile that caused a small resistance to develop in the sending units (sulphur) that would adversely affect the gauge reading.
Funny, right afterwards they came out with a whole series of commercials about how "CLEAN" their gasoline was.
I haven't seen one of those commercials in awhile. They must think there's been enough 'damage control'.