fuel sending unit

Topic: fuel sending unit (Read 4166 times) previous topic - next topic

fuel sending unit

Reply #15 – January 04, 2009, 07:21:28 PM

Did you check to see if the wire with the float was bent the same as the other one before installing it? It might be throwing of your reading.

fuel sending unit

Reply #16 – January 05, 2009, 12:41:55 AM

plug the sender into the harness and manually opperate it and watch the guage.

Im a little lost on this thread so i gotta catch up. you have another post on this issue and ill check there as well.

If your wiper arm contact is worn, it may be skipping over creating an open circuit. Open would equal zero ohms.

as for the float arm being bent,, the odds are slim unless little hoodlums got ahold of it and were playing with it like my boys when they were little.

I would love to have a traced out two line drawing of the actual bend so i can fix mine. the angle of that wire is calibrated and means the world to a proper reading guage.

what are the odds someone (hint hint) could post up the actual angle of the float arm?

fuel sending unit

Reply #17 – January 05, 2009, 08:01:29 AM

Digi
first one is 60 deg.
2nd one is 130 deg.

buttstuffog
first one is 50 deg.
2nd one is 140 deg.
starting and stopping levels are the same.
as long as you use that formula. It should be OK
I'll get a pic later tonight

jpc647
This may be the reason for your tank reading.
You should check to make sure both of your senders start and stop at the same place. I'm not sure if a sender from an 18 gal. tank is the same as one from a 22 gal. tank, or where the diff in tanks are.
also
I should have told you to clean the contacts in the sender before putting it back together. I had to do that in mine, because it sat for so long without being used past the 1/2 mark. I wasn't getting a good reading.
I just took a pencil eraser and shined up the entire board in the unit. the rheostat will get a build up on it where the arm hasn't traveled in a while.

fuel sending unit

Reply #18 – January 05, 2009, 01:16:44 PM

Alright well before I put the sending unit in the tank I moved the float up and down and the gauge seemed to move accordingly. The gauge look a few seconds to catch up to the sending unit.

Now that its been put in the tank it doesn't seem to work. I added 5 gallons and it barely moved to the red line on "E". I figured oh well the tank was almost dry and I thought maybe it could have a reserve section and it doesn't register on the gauge.I have since added 10 more gallons to the tank, which should bring it up pretty close to 3/4 and its barely about the 1/8 mark. It seems to teeter between the line right next to the red 8 and the second green mark.

Any ideas why this is happening? It seems the last few days I'm being bombarded with electrical stuff. First this them my temp gauge is acting wierd.

I've already swapped cluster thinking that might be it. Any input?

fuel sending unit

Reply #19 – January 05, 2009, 02:20:35 PM

What does the tester read at the dash when checking the fuel sender?
sounds like you have a wiring problem between front and back possible a broken wire if your not getting a full signal at the dash.

fuel sending unit

Reply #20 – January 05, 2009, 03:06:51 PM

Alright I got 46.8 Ohms at the cluster. I tested the y/w white in the drivers side plug and grounded it to the steering column. This should be somewhere close to half a tank, maybe a little more. But it barely moves past 1/8. I have two gauge clusters, swapped them out again, and they read the same thing. I don't think its a gauge, and im bashing my head into walls tot trying to determine what is wrong here.

fuel sending unit

Reply #21 – January 05, 2009, 05:36:22 PM

Should be about right for a half tank.
Did you test the gauge using the paper clip to se it it pegs the gauge?
I'm thinking your gauge problems are somehow tied together with the other problems you posted.
I guess you can also use your meter as a temp gas gauge if this car is a DD. Just attach it with alligator clips till we find a solution. You know the full and empty ranges at least
We don't want you runnin out of gas by accident.

fuel sending unit

Reply #22 – January 05, 2009, 07:14:00 PM

To test the guage, insert a paper clip in the connector (C491)
turn on key
gas needle will peg if its good
gas needle will peg if its a conventional cluster
gas needle will go to empty if its a digital cluster sender

Those were the instructions. I'm not really sure what that means. Isn't the gauge not going to plug in because of the paper clip?

fuel sending unit

Reply #23 – January 05, 2009, 07:31:48 PM

If that's the connector at the sender, the paperclip in the connector will make the gauge think that it's filled to the top in your car. just use the paperclip to jump the wires, instead of the sender connector..
If the gauge doesn't peg, the problem is after the sender.
There's probably another connector at the dash you can test the same way after you test the other one.

Did that make any sense?

fuel sending unit

Reply #24 – January 06, 2009, 02:38:23 PM

yeah that makes sense.

I was thinking about this last night and came up with a possible solution. I know the sending unit worked when i plugged it in, I tested in outside the tank and watched the gauge. Either it is getting bound up in the tank on something(not likely) or I was thinking if there is a crimped or squashed wire under the tank, maybe my multitester can pick up the 48.6 ohms at the cluster plug but maybe its faint and the gauge isn't strong enough for the cluster to pick up. This maybe be dumb, but im running out of other ideas.

fuel sending unit

Reply #25 – January 06, 2009, 05:19:40 PM

It would have to be a broken wire somewhere where you plugged it in I bet. You could try jiggling wires while someone watches the gauge or meter, or your going to have to start testing your wires.
you could always run a new wire and be done with it too.
do those wires run inside the car under the carpet?

fuel sending unit

Reply #26 – January 06, 2009, 05:57:47 PM

The EVTM says the wires run under the floor, I checked the corresponding ground and it seemed okay. The problem is most lilkely going to lie at the sending unit or at the gauges. I would imagine its not the cluster because i have two and they both are reading the same thing.

Could maybe something on the tank be grounding out? I mean its a new reprouction tank, but I just can't figure out why im getting a correct reading at the gauge plugs but the gauge doesn't display correctly.

There are 15 gallons in the car maybe a little more, it should be more than 1/8 or a tank. I put the car on the hill in my yard and it moved a little bit towards the 1/4 mark.

Also, look above at the picture I attached of the sending unit. On the left side of the picture the metal strip seems worn/dirty or something. Is this normal? Could this be the problem?

fuel sending unit

Reply #27 – January 06, 2009, 06:16:45 PM

If your getting the correct reading at the gauge plugs, then the problem has to after that. mabe the connector is the problem.

It worked fine, until it went into the car

did you use the paper clip to test it?

fuel sending unit

Reply #28 – January 06, 2009, 06:22:41 PM

which ones am i testing. C491 is in the trunk. But there are two plugs going into one. there are 4 little pins. Am I just jumping the yellow and white wire and the black one? Like completing the circuit for the sending unit without plugging it in?

fuel sending unit

Reply #29 – January 06, 2009, 06:42:33 PM

Sorry I ask dumb questions sometimes. I jumped the wired with a paper clip, the two pins from the sender side of plug c491. The gauge pegged. Way beyone full. What does this mean? That would mean the gauge works, and the sending unit appears to be sending the correct voltage, now I'll honestly say I'm confused.