Running through fuel level senders

[borgoth]

My fuel level sender in my 84 Carrera stopped working a couple of weeks ago. Not normally that surprising for a 22 year old car with 207k, except I replaced the sender Jan 05 (not working when I bought the car). Even more surprising, I was looking through the receipts from the PO and the fuel sender was replaced by a reputable local VA shop in mid-2004!

The way the sender stopped working this time was weird. I was driving on the highway for about 150 miles and noticed that the gauge hadn't moved. I pulled in to get gas, and when I unscrewed the filler cap there was a major hissing of pressure release (not sure if it were under vacuum or pressure). I filled up the tank and the gauge was working again. Got back on the road and maybe four or five times over the next hour and a half/ 100 miles I had sudden momentary power loss events, sort of a blip, usually when I hit an expansion bump or something. The power loss hasn't happened since (almost a month and a 900 mile high-speed trip back from the midwest to home on the east coast later), but the next day was the last time my fuel gauge worked.

I'm thinking something odd is going on with the fuel system (duh!), but no clue what. The fuel filter was replaced by the PO in mid 04, same time as the fuel sender, 12k ago.

Thoughts?

[nhromyak]

My guess would be too many amps are going through the sender, and/or gauges. That's a weird one.

Maybe check the fuses and see if they are all at the factory spec for fuses and what they should be according to either the cover or the book.

Oh-well, at least you got a bump.

Good luck.

[Jim Sims]

I suspect you simply have a loose connection somewhere and there may have been nothing wrong with any of the senders that were replaced. Given that replacing them appeared to fix the problem and the movement from pressure release or filling the tank resulted in a restoration of function I would closely examine the wiring harness connector that attaches to the sender.

The other loss of power sounds like another loose/bad major connection somewhere - start looking at the battery, then alternator and grounds.

Note on fuses: an incorrect fuse (higher rating than specified) will allow excessive current to flow but will not cause excessive current to flow. Excessive current flow requires a short or malfunctioning component in the circuit the fuse is protecting or too high of a system voltage.

[Early_S_Man]

Is there any possibility of gasohol in your tank??? Much higher tendency to absorb water ...

Most true sender failures are associated with corrosion on the slidewire, and gasohol can certainly provide the extra moisture to accelerate the corrosion process!