[bocomo1969]

Hey all - sorry for the silly question. Working on a 69 Chevelle complete restore. We are putting it back together again.

New gas tank new sending unit and new fuel line.

Is there a rubber/other connecting piece between the sending unit and the main fuel line?

It's been so long since we took it apart I can't remember any more.

Thanks and more silly questions sure to come

 

[jbarberggd]

Yes, depending on application, use rubber fuel hoses with clamps. I just did mine this last weekend and I attached the hoses (3/8" & 1/4" return about 8" long) to the sender before I installed the tank and then cut them to length to attach to the fuel lines. They were attached to original fuel lines.

 

[larrygk]

X2, yes.
Also have you tested the sender unit outside the tank (and inside it for that matter)? If not let us know....it can be the culprit of hours of misery. Can give you tips from first hand experience.

 

[bocomo1969]

X2, yes.
Also have you tested the sender unit outside the tank (and inside it for that matter)? If not let us know....it can be the culprit of hours of misery. Can give you tips from first hand experience.

No I have not. Please fill me in.

 

[larrygk]

Ok so here goes: Just because it is new does not mean it works. Where di you buy it?
When I say "works" the float may not float and you don't want to button everything up and then find out it doesn't as it is a pain in the butt to take the tank down, etc. So here are some tests to run. I am not expert but went thru this exact scenario. For the purpose of this discussion let us assume your wiring is correct. If if isn't that is another discussion:

1) On the bench put a multi-meter to both terminals on the sender to measure ohms. If it is in the tank take it back out. It's worth it. with the sender float hanging down (as if the tank was empty) you should measure 0 ohms. Now move it up and (I think you have a 69?) it should smoothly rise the ohms from 0 to 90 (empty to full). So at 1/2 way you should see around 45 ohms. If it does not then it is bad.

2) If that passes punch a hole in a piece of cardboard big enough for the base of the sender to fit into. If you can find a container...say a Tupperware thing deep enough where the float hangs into that but doesn't touch the bottom that is like your test gas tank. Rest the cardboard piece on top of the container just as the sender would be hanging in the tank so to speak. Now pour gas into it slowly and see if the float rises smoothly and without delay. Don't use water as water is denser than gas.

3) If that works and the ohms are still rising as you are doing this you are in good shape....but that assumes your wiring to grounds and to the gauge are good. Also make SURE you have a clean ground from sender to chassis and chassis to side tab of the tank.

Let me know if that works. If not then your sender is no good. I have gone through 2 new ones with the vendor swearing they have never had returns.

 

[larrygk]

Also I have not said anything about the potential of a bad gas gauge yet as I am leaving that until after you do (if you choose) the above test on the sender.

 

[bocomo1969]

Excellent - thanks. Great information.

I bought the tank and sender from Summit. Both are goodmark. I'll let you know how it goes.

 

[bocomo1969]

Got the multi meter but I am having a hard time figuring out what you mean by "both terminals on the sending unit"?

 

[larrygk]

So there is a short gold color post (sender wire terminal) and the ground tab on the side. Those are the 2 terminals....sender and ground.

 

[bocomo1969]

Thanks for the reply. I had it figured out shortly after the post. The sending unit measures on the money. 0 when it is all the way down and 90 at the top of rise.

I'll do the gas/tupperware test tomorrow.

 

[bocomo1969]

I have installed the tank but the Dash gauge is not working properly. In fact it sits on 6:00 and then moves counter clock wise to about the 3:00 position. It does this regardless if the sending wire is plugged in or not.

Pugging in the multi-meter to the sending wire and grounding on the trunk gives me about 17 on the OHM which makes sense as there is probably about 4 gallons of gas in the tank.

Any hints on how to begin the trouble shooting? I am not against dropping the tank again though I am hoping that would be the last step.