Hi guyz. i got a question. Before my 1986 IROC-Z broke down in 2002, the fuel gage meter was working. Just recently I got my Camaro up and going. The only problem is that every once in a while I got to fill up my tank because I dont know when my tank is almost empty. At fist the gage stayed all the way up and beyond full, now it stays at halfways. I remember that when I replaced the fuel pump 7 months ago, my uncle removed the sending unit and the floater swung a full 180 degrees open. So can it be that sending unit broke due to the half way swing, or can the fuel gage be bad? I know that the gage sort of works because when I turn the key to on, the needle moves slightly, but never correctly (as in it barely moves at halfway even when the tank is full).

 

Here’s how to test the fuel gage.

Remove the sender wire going to the gage.

Use a potentiometer with a value of 90Ω or the closest you can find.

Connect one end the potentiometer to the gage from the location you removed the sender.

Connect the wiper of the potentiometer to ground.

Turn the key to RUN.

Slowly adjust the p from 0Ω to 90Ω.

If the gage is bad it will exhibit the problem you have.

If the gage is good it will display a smooth transition from end of it’s range to the other.

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Happy Racing!

 

Okay. Ill do just that. thanks bro.

 

i went to Radio Shack and I found a lot of potentiometers. Do you have a suggestion of which one I should get? Also can I disconnect the harnes at the rear of the Camaro, nest to the tank and have some one in the seat to see if there is any fluctuation while doing the test?

 

Don't mean to stalk you Chevy86 Iroc-Z !!! Just happened upon this post

So, I'd like to help. I deal with a lot of fuel-contaminated tanks at work.
I'm not sure if this will be any help to you as you haven't given much info on your resurrection.
Your car sat for a long time. Did you use fuel stabilizer while it was stored? And it only lasts for maybe 1-1.5 yrs max without running it.
Did your tank smell rank when you decided to get it running again?
Varnished fuel can do all kinds of things to steel and galvnized stuff.

You asked about the 180 degree thing. If you wrap a sender past it's 'stays' it's OK. If you bent the 'stays' you can just bend them back, but I doubt you bent them, they're tough. They just stop your gauge from wrapping too far. What's more important is whether or not the fuel in your tank is bad.
Untreated fuel can rot steel, even galvanized surfaces. It will plug stuff.
So, getting past that, it may have caused your sending unit to stick in the spot it was at when you parked the car, or close to it as the fuel evaporated, and the float arm is now stuck to the support rod and reading "X".
When a sender is going or is bad, the gauge can jump around, eg; read sometimes full for awhile then go to near empty then read OK 'till empty or any combination.

Hate to say it but, if your gauge is not moving at all and your car sat a long time, do what was suggested to test your OHMs. If that shows no results, you may need to drop your tank and deal with the uglies.
If that is your issue and you don't have access to a shop who strips and restores tanks for a decent price, replace it and the sender new. Don't mess around, unless you're poor like me !!!!

 

Actually, my tank had a large hole in it. So there was no fuel in there for about 7 years. I found my Camaro in a junkyard (after being stolen and then illegally sold to the junkyard) and I guess in the processing yard, they punched a hole into it to drain the gas. Prior to the engine break down in 2003, the gage was working fine. But now it fluctuates very little when I turn on the IROC, but it never moves from it 1/2 tank mark.

 

Quote:

Originally Posted by Chevy86 IROC-Z

i went to Radio Shack and I found a lot of potentiometers. Do you have a suggestion of which one I should get? Also can I disconnect the harnes at the rear of the Camaro, nest to the tank and have some one in the seat to see if there is any fluctuation while doing the test?

The closest to 90Ω they list is a 25Ω rheostat part number 271-265.

Sometimes RadioShack has non-advertised items.

However if they only have the 25Ω rheostats you can put 4 in series to render 100Ω.

Yes, you can disconnect the sender wire at the tank end to test the gage with the rheostat.

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Happy Racing!

 

Okay. I did see one that is rated at 100K Ω. So is this the right one? Also how would I hook it up? Sorry for asking to many questions. I'm not familiar with circuitry.

 

100k is 1000 (one thousand) times more resistance than 100, and you are looking for 90 according to Nina.

You want something like this:
http://search.digikey.com/scripts/Dk...me=392JB101-ND

 

Okay guys, I recorded the issue with my fuel gage. Hopefully you'll get a better understanding of the issue at hand. Thanks for watching.

http://www.youtube.com/watch?v=kDfATT_qprU

 

I watched your U-Tube without sound (there is no sound on this terminal at my shop) and saw the gage go to about half way, then you pushed it back to empty.

It’s doing what you said in post 1.

Once you perform the test as described in post 2 you’ll know the answer.

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Happy Racing!

 

Ok. Ill perform the test that you told me about. Thanks NINA.

 

if you unplug the fuel guage float sending unit wire from the sender unit the needle should go past full with the key off.

SHOULD*

 

So if the gauge jumps passed full, what is bad? The sending unit?