I just flipped the resistor plate over to the unused side when I replaced my pump. The car had sat for 8 or so years beforehand so I'm not sure if it worked or not in the first place, but it works pretty well now. I run out of gas on the notch just before the E so I suppose its good enough.
Could you just adjust the gauge in the car if you ran out around 3 notches? Instead of dropping the tank?
That does work after a sort, if you just want the low end of the gauge to be closer. Benefit of taking out the tank is you can restore even operation across the range of the entire resistor, and get both the low and high end readings close to spec.
I also ran out of gas when i first got my car. A mechanic told me to use some gas treatment to clean the sending unit. Since then i have discoverd this...
GM Fuel System Treatment PLUS, designed to clean the fuel sending Unit from corrosion and fuel system deposits for 2006 and Prior All GM Cars and Trucks.
[This message has been edited by 88GT.FASTBACK (edited 12-26-2009).]
GM Fuel System Treatment PLUS, designed to clean the fuel sending Unit from corrosion and fuel system deposits for 2006 and Prior All GM Cars and Trucks.
Do you get this at the dealership? Is it available anywhere else?
That does work after a sort, if you just want the low end of the gauge to be closer. Benefit of taking out the tank is you can restore even operation across the range of the entire resistor, and get both the low and high end readings close to spec.
So even if i pulled the needle at full since its over full by like 1/8 of an inch and put it at full that wouldnt work? I figured it would since when I fill it it would read right on full instead of over and when I was down by empty it would be almost out instead of being out around 3notches
and Also interested in that fuel treatment stuff, does it actually work?
Here's a thought, when you have the sending unit out to repair it, just as well go ahead and replace the fuel pump too, kill two birds with one stone and might just save you from dropping the tank anytime to soon
Though the sender was different on my '87 GT, this guide gave me enough confidence to tackle the task when I replaced my fuel pump yesterday. On the '87, there's a metal cover with 3 tabs bent over it to capture the assembly and float arm. Some scrubbing with electrical contact cleaner helped the sender read pretty well over the full range, about 3 ohms high on at empty and full. Once I get some more gas in the tank, we'll see if this was the magic bullet to fixing my stuck fuel gauge.
When I adjusted my 88 sender to get to 0 I did what I had read on a post somewhere and soldered the bottom wrap or two of the wire to short them out. That way you get all the way to 0 ohms. Gage has been prefect for years...
I was thinking the same thing. I saw this a year or so ago, have the tank to my Formula out and wanted to do this before i put it back in. It took me an hour or so to find THIS thread. I found several others but because this starts of with "how to" it was a real beotch to find using search.
What I don't understand is you are calibrating the guage for an empty tank and I don't think it is possible to run the tank empty so it seems like you would still have a reading on the guage when the fuel level is too low for the pump to run. I understand that may not be an issue if you're running out while the guage reads 1/4 or so (like mine), but it seems like there should be a dimension for the float to be at when the guage reads "E" so you still have a half gallon or so of reserve.....or is the minimum travel for the float already slightly higher than the pickup point of the pump?
I am thinking of using the pump to remove as much fuel as possible from the tank, measuring the quantity of fuel left in the tank and then add a half gallon or so set the minimum Ohms level
[This message has been edited by jazz4cash (edited 10-16-2010).]
When I first opened up the tank, the lowest "empty" position of the float was in fact noticeably below the pickup level of the fuel pump. I bent the arm however so now the Empty position is somewhat above the bottom of the pump.
What I don't understand is you are calibrating the guage for an empty tank and I don't think it is possible to run the tank empty so it seems like you would still have a reading on the guage when the fuel level is too low for the pump to run. I understand that may not be an issue if you're running out while the guage reads 1/4 or so (like mine), but it seems like there should be a dimension for the float to be at when the guage reads "E" so you still have a half gallon or so of reserve.....or is the minimum travel for the float already slightly higher than the pickup point of the pump?
I am thinking of using the pump to remove as much fuel as possible from the tank, measuring the quantity of fuel left in the tank and then add a half gallon or so set the minimum Ohms level
Let me guess. You're one of those guys who sets their watch ahead 5 minutes so your not late right?
[This message has been edited by phonedawgz (edited 10-17-2010).]
Also the gas doesn't pour out of the tank as easy as one would expect. Not sure why you would measure how much gas is in the tank after the pick up stopped picking it up anyway. Just add the x amount of gas you want left when it hits empty and calibrate the gauge.
[This message has been edited by phonedawgz (edited 10-17-2010).]
Let me guess. You're one of those guys who sets their watch ahead 5 minutes so your not late right?
No...you're wrong. Fuel gages are typically calibrated to have bit of fuel still in the tank when the gage reads "E". Just the opposite of what our cars do.
Also the gas doesn't pour out of the tank as easy as one would expect. Not sure why you would measure how much gas is in the tank after the pick up stopped picking it up anyway. Just add the x amount of gas you want left when it hits empty and calibrate the gauge.
Yeah, you're right there's no need to measure the remaining fuel except I would be planning to get ALL the old nasty stuff out of the tank, so then I WOULD need to know the minimum quantity required for the pump to run before adding a reserve quantity and calibrating to that.
I have fixed several fuel sending units by soaking them in vinegar. After leaving in vinegar for over a day, pull it out rinse it off and let it dry. They read pretty well after that.
But if I had the choice, I'd like to know exactly where E is really. For example E is exactly on the empty side of the empty mark. So I actually know where the car will run out of gas. Say I was running late for work and I had to make the desision of do I really need to stop for gas, or can I make it.
quote
Originally posted by jazz4cash:
No...you're wrong. Fuel gages are typically calibrated to have bit of fuel still in the tank when the gage reads "E". Just the opposite of what our cars do.
Hello all I toke my sending unit apart today (87 gt) and as i was cleaning the wire coil i pulled the wire off the pop rivet. What can i do to fix this? I was thinking about getting some contact cleaner and trying to solder the thin wire back to the pop rivet. thank you for your help
I'm not sure that's a solderable wire. You might have to pop rivet it back in place
Yes, Resistance (Likely Nichrome) wire can't be soldered far as I know...
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
can i use a universe sender-unit and mount it to the sending unit i have now as long as it is a 0-90 ohm unit what I'm thinking is getting one off ebay or get one from a old nova and popping off the part that i need and attaching it to my sending unit thank you
A special note, if your going to use all original stuff, check to see the plastic pieces are fastened still and not deteriorating, I got mine and it had enough meat to still salvage, also, because of the plastic deteriorating the float was able to slide out just enough so that it wasnt making contact to send a signal to the gauge. I bent the sender's mounting position in such a way that its held in pretty well...
I did this last week with good results. Got it to read between 2-99ohms. Something I found out is that those two torx screws with the spring action are also used to fine tune the resistance reading at the extremes. When you adjust them it changes the contact at the edges and will help you get closer to 0 and 100. At least it did in my case.
I thought my gauge stopped working at a quarter tank. Come to find out my needle on my gauge was BARELY touching enough on the dial to stop it at a quarter tank. I filled up the tank, pulled the needle off and dremeled it down around the base so that it wouldn't touch the outer edge. It works perfectly now. When I put the needle back on I made sure that the needle sat right on F (full) so when it got down to E (empty) I knew it wasn't lieing to me. It works good now.
After putting a can of sea foam in my tank because of buying a car that had been setting , the fuel gauge has started working partially. the previous owner said it didn't at all. is seems like every tank of fuel it gets a little better. did the sea foam do it? idk maybe
After putting a can of sea foam in my tank because of buying a car that had been setting , the fuel gauge has started working partially. the previous owner said it didn't at all. is seems like every tank of fuel it gets a little better. did the sea foam do it? idk maybe
Anything that gets the crud out of the tank is gonna get caughtup somewhere else! Don't forget to change out your fuel filter maybe a week after doing any chemical cleaning inside the tank with something like Sea Foam. This way you will not have a clogged filter and a stalled car.
the sea foam wasnt done for crud in the tank( new tank and pump installed two years ago) , but just to keep injectors clean as one year old gas is burnt
Excellent timing; I'm replacing my fuel pump this weekend and this article is just what I need! I think those 3 or 4 times I ran the tank BONE dry took years off the old pump... Gas runs out at about 3/8 according to the gauge.
Nice write up and job on the fix. I will have to go this when I get a change. A good way to clean the contacts is a pencil eraser or pink eraser, they take off the oxide but don't abrade the surface especially a concern for plated surfaces, these are not so it wouldn’t hurt much in this case. Also it looks like from your pictures of the resistor which is wire wound, if you adjust the number of coils that are between your contact points you can change the resistance, the more wire wraps between contacts the more resistance. Not sure how it works but I would guess the slider contact (connected to the float) should touch the first wire from the contact at the top of the resistor to get close to 0 ohms. I would suspect adjusting this would give you the 0 ohm, adjusting the number of wraps from the contact to the full position of the float would give you the 90 ohms. If I know the size of the wire and what it is made out of, along with the dimensions of the resistor, I could calculate the number of wraps for 90 ohms.
Nice write up and job on the fix. I will have to go this when I get a change. A good way to clean the contacts is a pencil eraser or pink eraser, they take off the oxide but don't abrade the surface especially a concern for plated surfaces, these are not so it wouldn’t hurt much in this case. Also it looks like from your pictures of the resistor which is wire wound, if you adjust the number of coils that are between your contact points you can change the resistance, the more wire wraps between contacts the more resistance. Not sure how it works but I would guess the slider contact (connected to the float) should touch the first wire from the contact at the top of the resistor to get close to 0 ohms. I would suspect adjusting this would give you the 0 ohm, adjusting the number of wraps from the contact to the full position of the float would give you the 90 ohms. If I know the size of the wire and what it is made out of, along with the dimensions of the resistor, I could calculate the number of wraps for 90 ohms.
Nice write up and job on the fix. I will have to go this when I get a change. A good way to clean the contacts is a pencil eraser or pink eraser, they take off the oxide but don't abrade the surface especially a concern for plated surfaces, these are not so it wouldn’t hurt much in this case. Also it looks like from your pictures of the resistor which is wire wound, if you adjust the number of coils that are between your contact points you can change the resistance, the more wire wraps between contacts the more resistance. Not sure how it works but I would guess the slider contact (connected to the float) should touch the first wire from the contact at the top of the resistor to get close to 0 ohms. I would suspect adjusting this would give you the 0 ohm, adjusting the number of wraps from the contact to the full position of the float would give you the 90 ohms. If I know the size of the wire and what it is made out of, along with the dimensions of the resistor, I could calculate the number of wraps for 90 ohms.
Couldnt you count the wraps and divide it out? Say, 100 wraps giving 100 ohms, a wrong reading, would tell you to take 10 wraps off, giving you 90 ohms. Correct, or is it too simplistic?
How do you get a thread moved to the How To?
[This message has been edited by Stainless1911 (edited 10-06-2012).]
