Fuel quantity indication problems.

[ramon]

(Please see my intro in Cobalt page.)

So, my first squawk with this new to me 2006 Cobalt LS.

My fuel quantity indications have started to act up. When I fill up or top up gas, the initial indication on the needle and digital display seem to concur with each other.

As I drive away, almost within a few minutes, both start to show a lower level than what I jut put in and the endurance seems to drop accordingly.

This is obviously (or I should think) a sender issue.

My question is, is the sender in the tank or does this system use an external fuel totalizer and send this information electronically to the displays? or does the sender do all this?

I'm thinking it's pretty simple system and there is only a sender in the tank and that is my issue.

Unless someone has experienced this and can tell me otherwise.

Thanks.

 

[YelloEye]

Re: transmission rev

The sender is in the tank. What kind if mileage are you getting per tank? The fuel level gauge is notorious for dropping right after start, on a freeway drive if I flip the ignition it will show up to 1/4th higher than before.

 

[bluebaltz]

wow! mine does this lol! well, it drops to 7/8th after the first mile away from topping off the tank. at first i though i'm loosing fuel on the road but no lol

 

[YelloEye]

wow! mine does this lol! well, it drops to 7/8th after the first mile away from topping off the tank. at first i though i'm loosing fuel on the road but no lol

Does it go back up after cycling the ignition? Mine has never had that issue, but then I top mine off to the next dollar.

 

[bluebaltz]

Does it go back up after cycling the ignition? Mine has never had that issue, but then I top mine off to the next dollar.

no, not that i recall, i think it just 'sticks' at about 7/8th until it actually passes 7/8th in the tank & then it reads normally. (But imma fill up agin soon so i'll pay attention)

i've been curious on how the DIC remaining mileage is calculated... wondered if it used data from the sender...

 

[YelloEye]

I assume remaining mileage is an equation involving your average fuel economy and the amount of fuel the sender reports. You can test that by looking at the value on flat ground, then park it on an angle and cycle the ignition.

 

[bluebaltz]

does it calculate avg mpg from estimating fuel flow by the injector cycles? or is there an actual flow meter?

 

[YelloEye]

I think it's injector cycles and duty rate, don't quote me though. I can check my service books later when I have more battery.

 

[bluebaltz]

I think it's injector cycles and duty rate, don't quote me though. I can check my service books later when I have more battery.

awesome! i'd love to know! i hate relying on computers calculations when i don't know what they are getting data from...

 

[YelloEye]

Knew i forgot something, yesterday got busy and I forgot to check that. I'll try to remember today.