fuel sending unit test.
Thread Starter
Racer
Joined: Sep 2006
Posts: 446
Likes: 1
From: Punta Gorda Florida
fuel sending unit test.
I just pulled the fuel pump assembly, for two reasons. 1. I feel the fuel pump is not performing properly. 2. To check the fuel level sender.
1. the pump's socket was hanging by a couple threads....
2. I have the sending unit out (
) I can't remember off hand the proper way to do the ohms test.
Thanks in Advance
1. the pump's socket was hanging by a couple threads....
2. I have the sending unit out (
) I can't remember off hand the proper way to do the ohms test. Thanks in Advance
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
I just pulled the fuel pump assembly, for two reasons. 1. I feel the fuel pump is not performing properly. 2. To check the fuel level sender.
1. the pump's socket was hanging by a couple threads....
2. I have the sending unit out () I can't remember off hand the proper way to do the ohms test.
Thanks in Advance
1. the pump's socket was hanging by a couple threads....
2. I have the sending unit out (
) I can't remember off hand the proper way to do the ohms test. Thanks in Advance
Thread Starter
Racer
Joined: Sep 2006
Posts: 446
Likes: 1
From: Punta Gorda Florida
I've been trying to ohm it, I tried to clean it with brake clean... what a joke. For some reason I'm not registering when the arm moves?? everything looked good when I took it apart.
Which setting do I use?
And where do I place the ends of the multi-meter??
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
The Ohms setting.....the one with the omega sign.
The leads are fairly straight forward....you can check it right at the sender. Put one lead of the meter on the slider(contact bar and the other on one on the ends where the wire terminates to the coil wraps...or one wire should be purple and the other one black that feeds the sender.....stick a meter on each of these colored wires and move the float up and down to check for ohm changes at various positions....should be 0 ohms empty and 90 ohms full. Ensure that the transition is smooth when you move the float. Don't forget that there is a connector at the tank also...this maybe a reason for the pump and sender not to work as well....the pump and the sender share a common ground wire.
Le Mans Master
Joined: Jul 2007
Posts: 5,043
Likes: 8
From: Tampa Florida
Not a good idea to use brake cleaner plastic...it will weaken it or cause it to fracture. Ensure your using your meter correctly....look it up online with google if you have to. I you still can't get a reading from the sender use a very fine sand paper or finger nail file and very lightly sand the face of the sender's coil wraps(were the float bar contact strikes it) and the face of the contact bar....only do 3 strokes or so. Then try to take another reading.
Melting Slicks
Joined: Apr 2002
Posts: 2,118
Likes: 0
From: St. Charles, MO Route 66 Corvette Club
A tip for you on the cleaning process....DO NOT WIPE IN THE DIRECTION AS THE SENSOR ARM MOVES. Instead, wipe in the direction of the wire as it is wrapped around the insulator. Failure to do this properly can trash the sender unit.
I recently removed the pump assembly from my 89 and found that I could not clean the connections to achieve the proper resistance readings. I had to buy a new unit (everything but the pump itself) and found a new OEM for about $200. My fuel gauge is now working properly.
If anyone has a need for the old unit, it is free except for shipping.
I recently removed the pump assembly from my 89 and found that I could not clean the connections to achieve the proper resistance readings. I had to buy a new unit (everything but the pump itself) and found a new OEM for about $200. My fuel gauge is now working properly.
If anyone has a need for the old unit, it is free except for shipping.
Thread Starter
Racer
Joined: Sep 2006
Posts: 446
Likes: 1
From: Punta Gorda Florida
I have multiple Ohms settings, But I got it figured out after a few choice words and a visit from the girlfriend. 
Well, live and learn... I'll cross my fingers on this.
The sender works, it hung up at 1/4 tank but a little "cleaning" (no brake clean this time) and now it works perfectly.
There was a HUGE gain from this little endeavor!!
-Better throttle response
-Increase in muscular exhaust note
-Smooth Idle/cruising
-Quicker startup
-Not to mention the ability to shred 315's at will. (Previously it'd hook with no tire spin, and a brake stand could only be done with a/c off.)
This has to be the best, thing I've done so far for my baby.
The sender works, it hung up at 1/4 tank but a little "cleaning" (no brake clean this time) and now it works perfectly.
There was a HUGE gain from this little endeavor!!
-Better throttle response
-Increase in muscular exhaust note
-Smooth Idle/cruising
-Quicker startup
-Not to mention the ability to shred 315's at will. (Previously it'd hook with no tire spin, and a brake stand could only be done with a/c off.)
This has to be the best, thing I've done so far for my baby.
