1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Fuel Level Connector

Thread Tools
 
Search this Thread
 
Old Mar 21, 2015 | 11:56 AM
  #1  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Fuel Level Connector

As you can see the connector has corrosion and this is before I cleaned it up pretty good. The corrosion changes the resistance going to the fuel gauge giving me different responses of the fuel level. After I cleaned it up it went back to what it use to be for a while but after I washed my car last night and spraying that area it went back to changing levels and dropping below empty in a matter of minutes.
Attached Thumbnails Fuel Level Connector-image-992439930.jpg  
Reply
Old Mar 21, 2015 | 11:59 AM
  #2  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
These pictures were taken in less than 10 minutes. This was last night.
Attached Thumbnails Fuel Level Connector-image-1852594976.jpg   Fuel Level Connector-image-2393713723.jpg   Fuel Level Connector-image-1837331802.jpg  
Reply
Old Mar 23, 2015 | 06:36 AM
  #3  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Anybody know how to clean this connector up or have the same issue as me before?
Reply
Old Mar 23, 2015 | 10:01 AM
  #4  
DivinDriver's Avatar
1st-Class Engine Janitor
Tenured Member 10 Years
iTrader: (15)
 
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
There's supposed to be a plastic inner fender piece between the wheel well and the tank/sensor. Likely you'd have less trouble with this if that piece was where it's supposed to be.
Reply
Old Mar 23, 2015 | 10:40 AM
  #5  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Originally Posted by DivinDriver
There's supposed to be a plastic inner fender piece between the wheel well and the tank/sensor. Likely you'd have less trouble with this if that piece was where it's supposed to be.
Well damnnn.
Reply
Old Mar 23, 2015 | 12:06 PM
  #6  
t_g_farrell's Avatar
Waffles - hmmm good
Tenured Member: 20 Years
Community Favorite
iTrader: (1)
 
Joined: Jul 2004
Posts: 9,250
Likes: 464
From: Lake Wylie, N.C.
Also, the sensor gets its reference for ground through the round base that it mounts to. Over
time the contact between the base and outside part of the sensor that connects to the base for
that ground gets weak, so the resistance goes up. The way the gauge works is the higher the
resistance value, the more towards empty the needle points.

You can fix this without remove the sensor from the tank. You need to ground the base of the
sensor to the round base that bolts the sensor assembly into the tank. I did this by running a
wire from the sensor base and putting it under one of the mounting screws.
Reply
Old Mar 23, 2015 | 08:12 PM
  #7  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
I'll try to whip something up so it works on Wednesday, thanks.
Reply
Old Mar 24, 2015 | 03:13 PM
  #8  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Originally Posted by t_g_farrell
Also, the sensor gets its reference for ground through the round base that it mounts to. Over time the contact between the base and outside part of the sensor that connects to the base for that ground gets weak, so the resistance goes up. The way the gauge works is the higher the resistance value, the more towards empty the needle points. You can fix this without remove the sensor from the tank. You need to ground the base of the sensor to the round base that bolts the sensor assembly into the tank. I did this by running a wire from the sensor base and putting it under one of the mounting screws.
Could you get a picture of this setup, if possible?
Reply
Old Mar 25, 2015 | 10:34 AM
  #9  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Found out it was a bad ground, had the same idea that you had and did the same thing but ran outta time to finish it.
Reply
Old Mar 26, 2015 | 03:29 PM
  #10  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Well got it all working, but two things, it tells my my real fuel amount when the key is turned with the dash lights on but when I start the car the gauge drops down about 1/4 tank of what the real fuel amount is and the fuel light stay on and blinks (from fuel moving around?) Maybe it'll fix itself or something lol but I got it all working just there is a bug to it. Anybody have ideas of what this little bug could be?
Attached Thumbnails Fuel Level Connector-img_0626.jpg   Fuel Level Connector-img_0625.jpg   Fuel Level Connector-img_0627.jpg   Fuel Level Connector-img_0628.jpg   Fuel Level Connector-img_0631.jpg  


Last edited by Jere Urso; Mar 26, 2015 at 08:30 PM.
Reply
Old Mar 26, 2015 | 04:36 PM
  #11  
j9fd3s's Avatar
Moderator
Community Builder
Liked
Loved
Community Favorite
iTrader: (3)
 
Joined: Mar 2001
Posts: 31,833
Likes: 3,232
From: https://www2.mazda.com/en/100th/
250 Connectors
Reply
Old Mar 27, 2015 | 04:35 PM
  #12  
DivinDriver's Avatar
1st-Class Engine Janitor
Tenured Member 10 Years
iTrader: (15)
 
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
Here's the panel you're missing, for future reference:


Here's where it goes:
Name:  20150327_121414.jpg
Views: 67
Size:  263.0 KB
Reply
Old Mar 27, 2015 | 07:40 PM
  #13  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Originally Posted by DivinDriver
Here's the panel you're missing, for future reference: Here's where it goes:
Thanks.
My fuel light still stay stays on and now my gauge reads the same with the key on and when the car is started but I have a full tank and the fuel light stays on.
Reply
Old Mar 29, 2015 | 09:03 PM
  #14  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Well, found out that my ground caused parasitic load and my battery is now low and won't start my car so I threw it on the charger. Disconnected my ground until I figure out what's going on. Does anybody know how this fuel sending unit is wired or ever looked at the inside of it to help me out because I need it.
Reply
Old Mar 29, 2015 | 09:08 PM
  #15  
woodmv's Avatar
Village Idiot
Tenured Member: 10 Years
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Nov 2010
Posts: 1,088
Likes: 13
From: SE VA
DivingDriver did a write up on modifying an FB fuel sending unit to work on an SA. It's around here somewhere and is a good read with lots of pics and specs
Reply
Old Mar 29, 2015 | 09:12 PM
  #16  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Originally Posted by woodmv
DivingDriver did a write up on modifying an FB fuel sending unit to work on an SA. It's around here somewhere and is a good read with lots of pics and specs
Can you send me the link I'm on my phone and can't find it.
Reply
Old Mar 29, 2015 | 09:21 PM
  #17  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
But at the same time this doesn't make sense because if it was causing parasitic load wouldn't the gauge be reading with the key off?

Last edited by Jere Urso; Mar 29, 2015 at 09:34 PM.
Reply
Old Mar 30, 2015 | 10:35 AM
  #18  
woodmv's Avatar
Village Idiot
Tenured Member: 10 Years
Liked
Loved
Community Favorite
iTrader: (8)
 
Joined: Nov 2010
Posts: 1,088
Likes: 13
From: SE VA
Its in the archives section:

https://www.rx7club.com/1st-gen-arch...sender-786986/
Reply
Old Mar 30, 2015 | 11:07 AM
  #19  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
So while reading that, my ground wire has to be ground to the rivet in the middle of the baseplate and its not. That must be the reason it's all screwy, now I gotta figure how to get a good attachment of my ground on that corroded rivet.
Reply
Old Mar 30, 2015 | 03:42 PM
  #20  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Does anybody know if this is correct?
Reply
Old Mar 30, 2015 | 05:16 PM
  #21  
DivinDriver's Avatar
1st-Class Engine Janitor
Tenured Member 10 Years
iTrader: (15)
 
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
Originally Posted by Jere Urso
Can you send me the link I'm on my phone and can't find it.
https://www.rx7club.com/1st-gen-arch...sender-786986/
Reply
Old Mar 31, 2015 | 07:58 AM
  #22  
t_g_farrell's Avatar
Waffles - hmmm good
Tenured Member: 20 Years
Community Favorite
iTrader: (1)
 
Joined: Jul 2004
Posts: 9,250
Likes: 464
From: Lake Wylie, N.C.
Originally Posted by Jere Urso
So while reading that, my ground wire has to be ground to the rivet in the middle of the baseplate and its not. That must be the reason it's all screwy, now I gotta figure how to get a good attachment of my ground on that corroded rivet.
Yep, this is what I was referring to. I think I might have soldered it on there. Can't
remember now and then tucked the other end under one of the screws holding
the assembly to the tank.
Reply
Old Apr 8, 2015 | 09:27 AM
  #23  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Well, now its actually all working, after cleaning the copper contact where the old ground broke off I basically just dumped solder between the two connections to make sure it wouldn't break free. After I took this picture I heat shrunk electrical tape over the connection. If corrosion ever eats your ground for your fuel level sender, this is something you could do.
Attached Thumbnails Fuel Level Connector-flvlsndr.jpg  

Last edited by Jere Urso; Apr 8, 2015 at 09:31 AM.
Reply
Old Apr 15, 2015 | 10:00 AM
  #24  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Would the low fuel light come up if the gauge doesn't work? If the light illuminates with the others before starting means the connection is good? The ground must not be good enough because the gauge on the dash just quit working after a week of working lol Such a pain.
Reply
Old Apr 17, 2015 | 09:33 AM
  #25  
Jere Urso's Avatar
Thread Starter
Full Member
 
Joined: Sep 2014
Posts: 223
Likes: 1
From: A
Anybody know? I've been looking at schematics of the wiring but it doesn't really show the fuel level sender very good.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
Jul 1, 2023 04:40 PM
Skeese
Adaptronic Engine Mgmt - AUS
65
Mar 28, 2017 03:30 PM
86rxNa
2nd Generation Specific (1986-1992)
2
Aug 11, 2015 11:51 AM




All times are GMT -5. The time now is 03:51 AM.