1996 850 GLT Wagon Gas Gauge Never Reads Full

[454cid]

If it is not raining tomorrow, (starting to feel like I need webbed toes/fingers, and gills),

We had rain in MI for a few days, but now it's just really windy. It's holding up my spray painting!

I will pull the air filter box and see if the flapper between the hot air and cold air intake is FUBAR.
I replaced the Air Mass unit maybe 5 years back, and it seems like that is working O.K.

Isn't the GLT a low pressure turbo? ... or was that only on the later cars like my 99 S70? If you have a turbo, you won't have the flapper. I got rid of the flapper on my naturally aspirated 850 by switching to a lower air box from a turbo car.

The flapper in my 96 850 would hang out between both positions, and didn't affect starting at all.

[NotAnElectronicsGuy]

Here is an oddity... and thinking/hoping this *could" have been the problem all along. If I do not need to crawl into the gas tank- so to speak- or mess around with wires, floats, and etc., I will be very happy.

So, my rear springs were crapped out, badly, and the car was very low in the back, like 3,5" or so. Low enough that I bumped my head on the hatch.door when it was open, and I am only 5' 5"!

Got new heavy duty springs with thode rubber bushing on the top installed, and the rear end is noticeably higher. I will go fill up tomorrow [Monday] , and see where the gas gauge goes to.

Will let y'all know!

[NotAnElectronicsGuy]

Just for grins, where is your voltage level
hanging out when the car is running.
I’ve never heard of low system voltage
causing that particular problem, but
it’s always a good thing to consider
with electrical problems.

Voltage output from alternator checks proper level, (and a new battery, too).

[NotAnElectronicsGuy]

Well, the replacement springs getting the back of the Volvo to where it should be did change the position of the gas gauge needle a little bit.

When we were done replacing them, the needle went to 12 gallons. When I filled the tank it took 6.3 gallons, and the needle still read what I am guessing would be about 2.5~3 gallons below the 18 gallon level.

This means the gauge is correct at 12, low at full, (sticking there, maybe?), and when it goes down again on a highway driving trip this weekend, we will see what it looks like when I re-fill it on return on Monday.

And it looks like I am going to have to crawl into the gas tank, so to speak, and see what I can find there, after all.