I have a 1988 7.3L diesel
the water in fuel light keeps coming on and it wont start
i drained the tanks and the lines and the filter and i put fresh fuel in
i even tried unplugging the sensor
help please

 

Moved to proper forum.

 

Which sensor? The on in the water separator? Is it the stock water separator? If so, you should replace that POS and get a Racor. The stock unit tends to leak after you drain it the first time. This leads to bubbles in the fuel and that will keep the engine from starting. How long had it been sitting before the first episode of water? Is it possible you got fuel with water in it from the same place twice?

 

Have you changed the filter recently......is it freezing where you are. Did you put some fuel additiive in the tanks......


"Water In Fuel" Warning Indicator

The "WATER IN FUEL" warning indicator should turn on when the ignition switch is in the START position to indicate proper indicator and sensor function. The indicator will come on if the fuel filter/water separator has a significant amount of water in it. If the indicator comes on during normal engine operation, drain the fuel bowl in the filter as soon as possible. Water in the fuel could cause extensive damage to the fuel injection system.

Significant amount.... .01 of a qt/liter

There is the little wheel on the filter base, fastest and easiest is to place a bowl under the steel drainline, unscrew the wheel, remove the cap on the Schrader valve and push in the valve core. Fuel will drain into the bowl or on the ground if in a gravel area. (do not do the draining over asphalt) close the wheel when water is drained. Start the engine, some air will be in the system for the first few seconds. Drain fuel filter bases every 5000 miles/every oil change.

 

Check for water in bowl of the fuel filter. Drop the bottom of the filter into a clear glass so you can see if you have a water problem or not. Because of the specific gravity difference between water and diesel (0.78 vs 1.0) the water should stay on the bottom of the glass and the diesel fuel should float on top. There may only be a small drop of water at the bottom of the glass as that can be enought to set off the sensor.

If you don't get water consider a Racor replacement Filter Unit with a clear plastic bowl.

Change all the rubber hoses and orings on the injector return line fittings to make sure you are not getting air leaks into the fuel system.

My Water in Fuel light keep coming on occasionally on my 93' EVEN AFTER I had removed the sensors and the factory fuel filter set-up. I eventual just gave up and removed the light bulb as clearly some electrical fault or short was turning the "Water in Fuel" light on and off.

 

i have drained the tanks the lines and the filter
i think it has something to do with the ignition switch or the coil
any ideas

 

there is a recal on the ignition switch back in 1996 for my year of truck
will the still honor it

 

since this is a diesel - are the glow plugs working? this wasn't mentioned. Are you getting fuel to IP? Do you smell fuel at the exhaust? Does it rool over fast or very slowly?

 

since this is a diesel - are the glow plugs working? this wasn't mentioned. Are you getting fuel to IP? Do you smell fuel at the exhaust? Does it roll over fast or very slowly?

 

the ip works and i just checked the glow plugs

 

One thing that you might check is the electrical connection to the Fuel Shutoff Solenoid. I had to clean mine earlier today b/c the truck wouldn't start. The spade plug was covered in oil and it couldn't get power to the solenoid.

 

i dont mean to sound dumb but where is the fuel shutoff soleniod

 

It's the front wire on the injection pump. The pump is dead center on top of the engine - right in front of the air cleaner housing. The second wire is the high idle solenoid. Feel free to clean both connections while you're at it.

 

hey thanks ill try that
ill let you know how it goes

 

The fuel shutoff is the first electrical connector on the injection pump