Anybody had problems with intermittent fuel gauge? Seems at some below
1/2 a tank, it will sometimes drop to showing near empty, then next time you drive it jumps back up to near 1/2 tank, then gradually go down as fuel is used. Could this just be an intermittent connection on the fuel sender or are we talking changing the fuel level sensor? Was/is this a common problem of this era CV's? thanks, John RWell I've had similar experiences with a 1966 thunderbird, and with a 1983 grand marquis.
The fuel sending unit has a variable resistor basically, and as the float arm moves, the resistence is changed, which is reflected on the fuel gauge. On the t-bird, one of the parts of the resistor that is supposed to make contact with the other was just flat worn out, from moving up and down so much. So actually on that vehicle it reads emtpy.
On the grand marquis, I've actually had two separate issues:
The most recent (which has been a problem for about the past year at least, untill I finally got arround to fixing it a few months ago) was the float had a very very very very small crack in it, which allowed it to become filled with fuel, and therefore always sink, reading empty on the gauge. I finally got arround to replacing that float... costed like 2 bucks for a pair of them at the ford dealership.
The other problem I've had is with the voltate regulator for the fuel gauge system. Now I"m sure it's probably alot different on a 93 crown vic, but I think I had to turn the car on, unplug the voltage regulator board, and plug it back in, or something like that, and clean up the connectors with some alcohol (used edge connectors) while they were unplugged. This seemed to fix it.
I don't know how it works on a 93 though. It could be a voltage regulator issue...or for all I know it's controlled by a computer.
Do you have a shop manual? It seems like this problem ( for my car) was actually discussed in the shop manual.
Good luck,
Nic
Nic, Thanks for ideas, No I do not have a shop manual , but a friend has a '92 Lincoln TC, so it maybe close enough. JR
Robotnik wrote:
Yep, I do that too... only it's more like 180-200 miles for me, if it's all in-town.
Only I finally got the float replaced.... but I still don't trust the gauge enough.
Good ol' odometoer :-D
Nic
Ditto for me on my 91.
I hope you guys are getting better than 300 miles on a tank! Did the new design go with a smaller tank? I routinely get 320+ on a tank with my 302EFI.
BTW, my 91 had the same problems and I fixed it quite easily. The ground connection at the fuel pump gets corroded and can't pass electricity as "clean". The resistance gets all messed up and causes erratic gauge operation. Take off the pressure fit wire and use a BRASS wire brush to clean the threads on the stud. That fixed my problem some 20K miles ago. It's hard to get to, but it can be done without dropping the tank (at least on the 91).
I think I have roughly (or exactly?) the same size fuel tank... 18 US gallons, and mine's an older 302 EFI (1983). In town I get arround 11 mpg. I don't do alot of highway driving... and most of my in town driving is stop and go. Someone here told me I should get a tune up... but as long as I can remember, and from what my dad told me (they bought it in 1985 right before I was born) that's really about what it gets in town, even back then. So either it doesn't really need a tune up in that respect, or it's needed one for 19 years.
Nic
Thanks for the tip, I'll check that connection. As far as mileage, just drove to coast this past weekend, from Durham thru the "I-40" parking lot, then down US 70 to Moorehead area. I got 25.6 mpg on the CV w/
111k miles. BTW, I'm runn> Ditto for me on my 91.MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.