screwy fuel gauge, is it sending unit?

[donlightbody]

88 BII 2.9 4x 5sp. 23 gal tank, the gauge slowly works its way to empty in about 200mi, going slightly under E then back to just above E around 300 mi and back below around 320 well, at 200mi, I still have over a half tank. Can usually get around 500mi. Is this more likely to be a guage or sending unit issue? I'm thinking sending unit... Had her for about 13 yrs now and it's always been strange, but it used to go below empty after 70-80 mi, then back close to accurate around 100-120
:tease:

[martin]

It certainly sounds like the sender.

[RobbieD]

Based on the description, the sending unit would be my first quess, too.

[donlightbody]

Thanks guys, that's what I was thinking. Guess she gets a new sending unit.

[Jspafford]

Wait, you get 500 miles to a tank. What MPG does that average out too? I average 21-24MPG. But I always fill up at about 320 miles. Hrmm.

[donlightbody]

yep, I ran it dry a few years ago to drop the tank and change the boost fuel pump and had 497mi when she ran out. That's only 21.6 avg. I've seen 27mpg on a highway trip. With a 23 gal tank we can go go go. Sounds like your sending unit might be bad too.

[Lowrange2]

yep, I ran it dry a few years ago to drop the tank and change the boost fuel pump and had 497mi when she ran out. That's only 21.6 avg. I've seen 27mpg on a highway trip. With a 23 gal tank we can go go go. Sounds like your sending unit might be bad too.

I'm having fun with my fuel gauge in my 88 Ranger now... maybe this is the case. I recently took the bed off to replace the pump in the tank and re installed the bed, drove straight to the gas station and put about 10 gallons in the tank. The gauge worked fine and went straight to 3/4 tank. Then I drove it till it went down to empty. After that I pput 10 bucks back into it and the gauge hasn't moved yet. I've put gas in it several times and it won't move! I wonder whats up.

[Lowrange2]

Wow... 3 days with no response... Whats the ohm range supposed to be coming from the sender?

[martin]

Depending on the year of the truck the sender is either 75 ohms or 150 ohms.