So I've been trying to figure out if my gauge or sending unit is bad in my 87 IROC. The gauge always reads a little above a quarter tank and doesn't move. I unplugged the body plug under the rear axle and turned the key on. The gauge read passed full. I then shorted out the tan and black at the body connector and turned the key on and the gauge still reads passed full. Does not read empty. I checked the OHM's on the purple and black wire at the plug going to the sending unit in the tank and that reads a constant 35.3 OHM's and not showing an open circuit. The fuel pump had been changed in the passed. Is it possible the float is caught on something or is the gauge bad?


UPDATE 2/28/2017: I had posted that I shorted the ground and tan wire at the body together for the gauge which I did see someones post on that. That was incorrect since that is the wire for the pump. I have since tested the purple wire at the body and with no plug the gauge reads full and with the ground shorted to the purple wire it shows empty. So this weekend I will be pulling my fuel tank and looking at the sending unit since the gauge is showing as working.

 

The problem I had with my 1984 Z28 was that the gauge would sit past full all of the time. After pulling the instrument cluster I noticed that one of the contacts where the wiring harness plugs into the cluster had gotten pushed back and wasn't making full contact. Fixed that and the gauge is working.

 

Hey, Can anyone help me out? I changed my fuel pump and sending unit in my 88 TA and the gas gauge reads empty. The tank is full. Even when I unplug the unit and turn the key on it still reads empty.

 

I have a similar issue. 85 iroc z guel gauge not reading. Installed a new fuel sender and still nothing. I believe the harness on the fuel sender where you plug into..is bad. Dont know what the hell its called. If anyone knows what it is please let me know.

 

Sounds exactly like the problem I had with my Z28, are all of the plug connections making contact?

 

[QUOTE=twentyyearwait;6387027]Sounds exactly like the problem I had with my Z28, are all of the plug connections making contact?[/QUOT

Im not sure. This car is an iroc z...but the previous owner butchered the hell out of it. I found a new pigtail connector on ebay for $15.
i installed a new fuel sending unit with some modifications. Ill try to explain this. Previous owner had a fuel pump (the one that bolts to the block. I have an external fuel pump now from holley bc my engine is carb. So the previous owner had the sending unit modified with no orignal fuel pump... Just a rubber fuel hose attached to a J piece copper tubing to a fuel strainer. I copied the idea and slightly modified it...with a rubber fuel line and strainer. I turned on my fuel pump and it still works but my gauge is not reading at all. I cleaned my fuel gauge with a wire brush and still nothing.

 

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