1986 Gas gage problems
Senior User
Joined: Mar 2003
Posts: 288
Likes: 0
From: Northeast Wisconsin
1986 Gas gage problems
The fuel level sending unit is a cheap printed circuit board with a wiper arrangement, similar to the rheostat volume control in a radio, located IN the fuel tank. They are notorious for going to pot. Both of mine on my '87 (front & rear tanks) have intermittent readings. The only way to fix the problem is to install new sending units, which means you have to pull the tank to get at it, as they're installed from the top. I was unable to buy the 50-cent piece I needed, only the entire float & sender assembly.
You'll probably find the only time it works right is when the tank is completely full, as there's been minimal wear at this point on the wiper contacts. All the other contact points on the wiper path have been worn off.
Short of removing the tank(s), just use your trip odometer to tell you when to fill up again. I can get about 250-270 miles on my 19-gallon tank before I have to gas up again. Base yours on what you've been getting for average mileage.
I hope this helps.
You'll probably find the only time it works right is when the tank is completely full, as there's been minimal wear at this point on the wiper contacts. All the other contact points on the wiper path have been worn off.
Short of removing the tank(s), just use your trip odometer to tell you when to fill up again. I can get about 250-270 miles on my 19-gallon tank before I have to gas up again. Base yours on what you've been getting for average mileage.
I hope this helps.
Thread Starter
|
New User
Joined: Mar 2002
Posts: 5
Likes: 0
From: oklahoma usa
1986 Gas gage problems
i got at mirror and looked at the top of the tank and saw the sending unit. I don;t see how I would remove the old sending unit . I dont see any bolts ?
I may just keep using the odometer
I may just keep using the odometer
Senior User
Joined: Mar 2003
Posts: 288
Likes: 0
From: Northeast Wisconsin
1986 Gas gage problems
There are no bolts used. Everything inside the tank (fuel level sensing mechanism, the in-tank low pressure fuel pump, fuel line discharge, and tank vent line are all mounted on a plate which is about 4 or 5 inches in diameter. This plate, along with a large rubber gasket on the tank side, fits onto the tank in a special ring fitting where it locks into place with about a 90-degree twist. You need a drift ("a flat-nosed punch") and a mall hammer to unscrew this plate from its receiver mount. Because it's on top of the tank, rocks, dirt, and moisture (causing rust) make getting this assembly apart somewhat difficult even when the tank has been physically removed from the truck.
If you attempt the repair, run the tank almost dry of gas before removing it from the truck, since each gallon weighs about 8.5 pounds. Use a NON-SPARKING drift made of brass, copper, or wood to disengage the plate. Remember, also, no smoking or open flame around the removed tank, and be careful you don't drag it across the concrete garage floor to make sparks! Obviously, don't use a torch to help loosen the plate from its mount, either!
If you attempt the repair, run the tank almost dry of gas before removing it from the truck, since each gallon weighs about 8.5 pounds. Use a NON-SPARKING drift made of brass, copper, or wood to disengage the plate. Remember, also, no smoking or open flame around the removed tank, and be careful you don't drag it across the concrete garage floor to make sparks! Obviously, don't use a torch to help loosen the plate from its mount, either!
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
1986 Gas gage problems
The non-EFI tank opening is only ~2 3/8", but it's removed just like these pics show.
Thread
Thread Starter
Forum
Replies
Last Post
fordfinatic
Cooling, Heating, Ventilation & A/C
2
May 14, 2006 10:21 PM
jelks
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
2
Feb 8, 2004 08:09 PM
mrcoffee23
1987 - 1996 F150 & Larger F-Series Trucks
3
Mar 5, 2003 10:08 AM
