9 replies to this topic

[Eds.mini.lulu]

Having some issues with the fuel gauge reading correctly.

So I have a 93 carb mini, with Nippon siekki clocks.

The fuel gauge isn't reading correctly.
So here's what I've checked.

I connected the 2 wires at the sender together. The tank read full.

I then took the sender out the vehicle with the wires connected I moved the sender. When I moved the sender to full position. The gauge only read 3/4 full. And then returned to empty when sender dropped back down. Does this point to a Dodgy sender or will this be the voltage regulator?

I have also done some voltage checks at the sender and also continuity checks both seemed ok.

Any help with this will be greatly appreciated.

Also mention the sender unit is only maybe a year or so old.

Thanks in advance.
Ed

[cal844]

Bad sender, test your new one before you fit it

[Eds.mini.lulu]

Ok, that's annoying. I think I may have previously bought the wrong one as I have a 1993 late carb mini. And the 2 that are available are either pre injection or injection from 1992. I have emailed mini Soares's for advise as well.

[Eds.mini.lulu]

Also adding I have done some resistance testing on the sender unit.

I set my multimeter to 200ohms(highest it goes)
When full the sender was reading around 15-20ohms did fluctuate. (I reckon I have about half maybe just under a tank, and my fuel gauge is reading just above empty)

When testing for empty was difficult to get a reading would fluctuate alot highest reading was about 180ohms but then the reading would just say -1. Is that because it has gone beyond the range of my multimeter?

Also tested the resistance with the sender back in the car. Resistance was reading about 75-90. With this reading I would expect the gauge to be reading higher.

Is this all still pointing to a Dodgy sender unit?

Tia.

Ed

[cal844]

Also adding I have done some resistance testing on the sender unit.

I set my multimeter to 200ohms(highest it goes)
When full the sender was reading around 15-20ohms did fluctuate. (I reckon I have about half maybe just under a tank, and my fuel gauge is reading just above empty)

When testing for empty was difficult to get a reading would fluctuate alot highest reading was about 180ohms but then the reading would just say -1. Is that because it has gone beyond the range of my multimeter?

Also tested the resistance with the sender back in the car. Resistance was reading about 75-90. With this reading I would expect the gauge to be reading higher.

Is this all still pointing to a Dodgy sender unit?

Tia.

Ed

The -1 is either open circuit OR the meter isn't rated enough.

I'd still say that your looking at a faulty sender. Siphon the fuel, remove the sender and test the sender manually whilst observing the guage. Ensure you have the wiring on the sender before you turn the ignition

Edited by cal844, 06 April 2020 - 04:28 PM.

[Eds.mini.lulu]

Also adding I have done some resistance testing on the sender unit.

I set my multimeter to 200ohms(highest it goes)
When full the sender was reading around 15-20ohms did fluctuate. (I reckon I have about half maybe just under a tank, and my fuel gauge is reading just above empty)

When testing for empty was difficult to get a reading would fluctuate alot highest reading was about 180ohms but then the reading would just say -1. Is that because it has gone beyond the range of my multimeter?

Also tested the resistance with the sender back in the car. Resistance was reading about 75-90. With this reading I would expect the gauge to be reading higher.

Is this all still pointing to a Dodgy sender unit?

Tia.

Ed

The -1 is either open circuit OR the meter isn't rated enough.

I'd still say that your looking at a faulty sender. Siphon the fuel, remove the sender and test the sender manually whilst observing the guage. Ensure you have the wiring on the sender before you turn the ignition

Hi yeah I had removed the sender to check it. I checked how much fuel I had before I removed the sender.

When testing it manually in its highest position it still only read 3/4 full.

Just annoying as the sender isn't even a year old.

Thanks for the help,
Looks like I'll have to get a new sender. I mentioned to minispares I only bought it last June so here's hoping they're feeling nice and let me swap it.

[Spider]

The Sender's do have some adjustment in them.

 

If you look at the back side from the arm side of the sender, you'll see on the other side of the arm, there's a small brass looking slot screw head.

 

By holding the arm and moving this, it changes the the position of the Arm relative to the resistor in the sender.

 

If the sender is a few years old, you might need to make the initial move using some pliers just to 'free' it  up, though, they are normally stiff.

 

If you have a Mulitimeter, check the resistance. At Full it should be 33 ohms. Empty is 250 ohms.

< Edit;- This is the adjuster here (thanks to Matt Read for putting me on to this a few years back)

 >

Edited by Moke Spider, 12 May 2020 - 08:26 PM.

[Eds.mini.lulu]

The Sender's do have some adjustment in them.
 
If you look at the back side from the arm side of the sender, you'll see on the other side of the arm, there's a small brass looking slot screw head.
 
By holding the arm and moving this, it changes the the position of the Arm relative to the resistor in the sender.
 
If the sender is a few years old, you might need to make the initial move using some pliers just to 'free' it  up, though, they are normally stiff.
 
If you have a Mulitimeter, check the resistance. At Full it should be 33 ohms. Empty is 250 ohms.

< Edit;- This is the adjuster here (thanks to Matt Read for putting me on to this a few years back)



 >

Thanks for the advice
Played with the screw and got it reading better. Cheers.

[dunkyb]

I got a new fuel sender for my MPi mini from minispares - On max it seems to read 250ohms and min 15ohms.  Can't see how to adjust it, as the little adjuster only seems to move the arm and won't turn without

moving the arm? (Don't want to force it, will practice on the old one once out the car!)

 

When plugged into the car's wiring, the new sender still shows a few mm less than the 'full' line on the gauge, but a lot better than the old sender anyhow... Would be nice to get it spot on!!

[Spider]

I got a new fuel sender for my MPi mini from minispares - On max it seems to read 250ohms and min 15ohms.  Can't see how to adjust it, as the little adjuster only seems to move the arm and won't turn without

moving the arm? (Don't want to force it, will practice on the old one once out the car!)

 

When plugged into the car's wiring, the new sender still shows a few mm less than the 'full' line on the gauge, but a lot better than the old sender anyhow... Would be nice to get it spot on!!

 

These are tight, it's just a friction connection and I do stress, they are tight !  I did suggest ^ that you may need a pair of pliers to get i to start moving and you need to hold the arm !!

 

I'd say though, this may not need adjusting in your case. The arm may need a little bending as it can foul on the filler neck on it's way up. Try it with the sender out of the tank to see if it sends the gauge up to full.

 

The Smiths Gauges were also adjustable. I'm not sure if the Japanese gauges have this.