'83 Fuel Tank Capacity

[starryknite]

Hi guys,

Per the driver's manual on page 53, it states that the fuel capacity should be 66 liters. That comes out to 17.4 gallons.

It also says that the warning light comes on when about 9 liter (1.98 Imp. gals.) of fuel remaining.

Even with the gas light on, I only put in about 12-13 gallons at best. That means Im missing about 2 gallons. Dirt in the tank?

Is this enough cause to remove and inspector the tank?

[guru944]

I would drain the Gas Tank and service the In Tank screen/filter, fuel Lines, to Fuel pump, and Fuel filter.
Consider Flushing the tank out to remove any buildup in there. Tank would not require removal to accomplish this....
Keep us posted...Later...

[Pauld_94S2]

Hi!

Pickup a 5 gal plastic gas can; Harbor Freight or Home Depot.
Fill up the gas can with exactly 5 gallons of gas and drive your 944 until you run out of gas.
Pour the 5 gallons in and go to a gas station, fill up the tank.

Add them together and see how much you put in.
My guess is the sending unit is way off.

[smudo]

Originally Posted by Pauld_94S2

Hi!

Pickup a 5 gal plastic gas can; Harbor Freight or Home Depot.
Fill up the gas can with exactly 5 gallons of gas and drive your 944 until you run out of gas.
Pour the 5 gallons in and go to a gas station, fill up the tank.

Add them together and see how much you put in.
My guess is the sending unit is way off.

If there is dirt in the bottom of the tank, you may force it to go trough the fuel system by doing that. The fuel system of 944 is not so sensitive as of the modern cars but still it may not be good.

[Freaky]

Do you realize how much dirt it would take to displace 2 gallons of fuel? The dirt/sludge would be so deep in the tank that the fuel pickup would be blocked.

We are talking pounds of dirt, someone would have had to literally pour dirt that much dirt into the tank.

Remember that the tank outlet is in the BOTTOM corner of the tank. I had a similar problem with my 951, it has a 21.1 gallon tank, but when I fueled up, for some reason, the pump at gas stations would click off at about 18-19 gallons. I could fill it the rest of the way if I took it easy and slowly pumped in more gas.

It turned out to be the gas tank vent system was blocked. Cleaned the expansion tank, shut-off valve and vacuum valve and everything is fine now.

Your car has 2 expansion tanks, one located in the right rear of the cargo compartment, under the cover over the tank filler tube, and one located on the top of the fuel tank, you also have a shut-off valve and a ventilation valve (also under the filler tube cover), if any of these are blocked (or the lines) the fuel tank can't vent air pressure when filling, the automatic shut-off on the service station pump will trigger.

[guru944]

Your vent may be malfunctioning as "Freaky" suggests.
Water is also heavier than gasoline and it will begin separating from your fuel in any container beginning or after~ 28-30 days.
I suspect Water and dirt in your tank as well. That is why i suggested a complete drain and flush.
I did mine in the driveway, on the ground with a hydraulic floor jack and jack stands and some tools.
also verify your tank vent/evap system is working properly.
Later...

[Rasta Monsta]

Originally Posted by smudo

If there is dirt in the bottom of the tank, you may force it to go trough the fuel system by doing that.

Lolz. Pickup is at the bottom of the tank, where the "dirt" would likely be even when full.

[pfarah]

Starry,

Your fuel sending unit may be acting up. It's easy to remove the unit and clean the internal wires, just be careful as they are quite thin. Also, install a new gasket when re-installing the sender to avoid potential leaks. My 84 had the same issue upon purchase but works great since the maintenance; Clarks Garage has the tutorial.

[John_AZ]

1. Read the tutorial and clean the fuel tank sender.
Fuel Level Sender Cleaning

WARNING! Be extremely careful with the thin silver wire. I use a pair of Q tips wet with fuel injection cleaner and gently slide down the wire to clean. I do not touch the copper contacts that slide on the silver wire.
New senders are about $169.99??

Get a new fuel tank sender seal.

Get a new tank drain screen and seal.
Get a new hose from the tank to the pump.
Change your fuel filter.

The early 944 tank is the same as the 924S.

J_AZ

[Tom944]

I had a similar problem. It was quickly solved by cleaning the grounds behind the gauges.

[starryknite]

Thanks guys for all the advise. Its always appreciated.

Ill post an update when all the parts arrive