Hey everyone, I did some searching and wasnt able to locate a similar problem to what I have been dealing with. My 88 Bronco, When full the gauge will read at 1/4 tank...As I drive, the gauge will move towards the Full side lol...But at the Full mark, it is exactly at 1/2 tank lol. It been like that since we got rid of the Factory fuel pumps and now using an in-line aftermarket one. My Bronc is an 88, 351w, C6...not F.Ied anymore...when I bought her she was half-!@sed to carb. it still had the PCM and TFI dist. with a old "boat anchor" 2bbl iron intake. and a gummed up 4bbl carb with adapter plate for the intake. oh and still had both fuel pumps wired in as well( not sure why the cheap pressure reg leaked lol) I rebuilt the carb, intalled a Weiand Stealth aluminum intake, Blue tab module, and a Mr Gasket inline pump, i did run a 84 spec dist w/ vac adv...and vacuum adv didnt work, Ill have MSD with mech when im done putting here back together from the rebuild. but anyway, i didnt wire in the the new fuel pump then, a local shop did. and it runs threw the factory fuel pump relay. I do notice what appears to be a ground wire coming from the top of the tank to the frame..one of the only spots where there is surface rust and there is some slack in the wire as well. I know guages usually dont go bad, but i did put another one in from a JY truck, i matched the part #s up and the price was right and included a free replace warranty. Ive seen alot of ppl having other guage issues and the sending unit is the cause, but my issue is different so i wanted to get some opinions before i go out and replace it. Thanks everyone!!

DD: 84 F250 XL supercab, 420 IH idi, 4spd, 2wd, 175K
My "Baby": 88 Bronco XLT, 358w, built C6, 4.10s, 400hp & 500ft lbs(est.) 55k original miles
Toy: 08 Kawisaki KFX450R, Full DRD pipe

 

Sounds like rhe wires are reversed on the sender. Make sure it has a clean ground too.