Water in Fuel Light, what does it mean?

[Oldhenry1]

Searched this, results are all over the map. I'm new to the 7.3IDI(and Diesels period). My new to me truck (1991 7.3IDI 4x4) has the Water in fuel Light on. It wasn't on when I got it about a month ago. What does it mean? What should I check/replace? It's winter here in the Real Washington(not the one with all the hot air) but it doesn't really get very cold here(below freezing lately). I'm looking for a place to start looking. Any help would be greatly appreciated.

 

[riotwarrior]

What does the Water in fuel light mean?

Generally speaking it means there is water in the fuel. It is a sensor on bottom of filter cap.

I would suggest replacing filter if you do not know age of it. If you do knkw age of it maybe open the drain on bottom...the proverbial knurled knob...it is to drain out water..tighten it up drive see if light goes out.

If not perhaps replace fuel filter and when doing so clean out the base cap well a d ensure no crud or water is left in it.

JM7.3CW

 

[icanfixall]

Welcome to the forum. Water In Fuel light means mostly there is some water in the fuel and the sensor found at the bottom of the fuel filter is telling you this but.. Sometimes this can be a wrong reading too. We do have a thumb screw under the bottom of the filter for draining off some water or fuel. Your filter may still have the small drain tube running down the side of the filter mount bracket. If its gone no problem. Just reach under and unscrew the brass thumb screw till the fluid drains off. You might want to collect it just to see if really water is in there. If it is wet with water you really need to find out where the water came from. Did you use a different filling station or use a farm fuel tank. Just try to figure out where the water came from. Mine would come on when it rained round here. Then drive it a few miles to make some heat under the hood and the light goes out. Best bet is to read up on changing a fuel filter. My advice is when changing the filter make sure you fill the new filter with auto trans fluid or diesel. But make sure you only pour in in thru the outside small holes around the edge of the filter. DO NOT POUR IT DOWN THE BIG EASY CENTER HOLE. Doing that your dirt will not be filtered out and ruining your injection pump is a big probability.

 

[crash-harris]

Also check the wire on the sensor. Like riot said, on the bottom of the fuel filter. If it's not there, find it and see if it's grounding somewhere. It looks like the push on connector on the top of the fender mounted starter relay that sends a signal from the ignition. It's just a slightly larger version. When I bought my truck the light had been on since the previous owner bought it. Someone had grounded it when they replaced the engine. Follow the wire and see if it's worn anywhere or contacting a grounding point. The sensor works by grounding through the water if it enters the fuel filter. If the wire isn't grounded out anywhere, do what riot said. If you don't know when the fuel filter was changed last, do yourself a favor and replace it. My injectors may had lasted longer had I done that sooner.

 

[lotzagoodstuff]

Welcome to the forum.

You should have a bleeder on the bottom of the filter. If you don't have a tube attached to the bleeder, I would suggest running a hose or tube to someplace easy/convenient and occasionally (like right now due to the Water In Fuel light being on) pulling off about one clear beer bottle (you could use a clear jar, but I always have a beer bottle handy) of fuel and taking a look at it. If your truck sat, or you got water/algae/rust/any other foreign matter in your fuel tank, you'll get to take a look at it.

You should also start paying attention to where you are buying fuel. I lived in the Real Washington, and I got a tank of fuel that had one full beer bottle of water in it. Shut my truck down like the turning the key off. It's hard to prove where/how it got in there, but I never bought fuel from that location ever again.

If you happen to change your fuel filter during this WIF investigation, do a quick search and follow the directions (engine hot and AFT or dieselkleen in the filter, don't crank the starter too much).

Good luck and again welcome to the forum.

 

[Oldhenry1]

I drained the filter without taking it off. What came out was the color of Prestone antifreeze. Smelled like Fuel, felt like Fuel, looked like Antifreeze(kinda weird). I think there is a new filter in my future. The Light is still on(but dimmer than it was). The fuel in the tanks is the fuel that was onboard when I bought the truck. Almost full in front and nearly empty in the rear tank. I try and start it every day or two since it's below freezing these days. I use Seafoam in my gas stuff but not sure about the Diesel angle no matter what the label says.
Thank you everyone for your help. I will keep you posted on the results.
Oldhenry1, out for now.

 

[79jasper]

Any chance you kept what you drained out?
Some diesel is slightly yellowish.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[Oldhenry1]

I did keep it, it's more green than yellow. Almost the color of Prestone Antifreeze but a thinner color green, you can see through it. I drove the truck today to fuel up the nearly empty rear tank. Only about 5 miles or so. The Water in Fuel light is now out. Besides the spin on filter above the intake, is there another fuel filter in the system? Down on the frame maybe?

 

[OLDBULL8]

Welcome to the OB.
There are several different types of filter used. One is a spin on with a drain **** on the bottom, another is a spin on with no drain at all, in that case, sometimes a water filter is used and mounted who knows where, on your 91 the OEM has a spin on filter that's replaceable and has lower cup that screws onto the filter with a drain on it. See pic. This type of filter can have dirt around the sensor that will trigger the WIF light.

 

[Oldhenry1]

What I have on mine is a Wix spin on with a solid plastic thumbscrew drain on the bottom of it. With the color of the stuff that came out of it, it's definitely time for replacement. I'd like to replace any other filters in the system. Can anyone recommend a good maintenance manual? My truck is a 1991 SC 4x4.

 

[icanfixall]

When you talk to a counter person about this filter just tell them what year truck and what type of filter you have. Of course its a spin on but it dose not have the separate spin on bottom piece. I will find the piece pictured above by old bull 8.
I realize this is expensive but you only need the bottom piece and the water in fuel sensor plus the drain valve pictured at the bottom of this ebay item. You do not need the heater. The top housing or the large threaded piece the filter spins on. Best to find this piece on many wrecking yard engines that are diesel idi ford engines. You can even take this off of a van and it will work.
http://www.ebay.com/itm/OEM-Genuine...ash=item35d88b0aa7:g:VKYAAOSwZ1lWeCWb&vxp=mtr

 

[crash-harris]

WIX 33417 is a spin on with just a drain, no sensor port.
WIX 33805 is a spin on with a drain and a sensor port.
WIX 33617 is a spin on with drain and sensor port, but sensor port is for 7/16-20 sensor.

I grabbed a Hastings FF1039SP when I ordered my junk from Rock Auto.

Someone had done away with the bottom part of the fuel filter bowl before I got the truck. Had a WIX 33417 on it...and the sensor wire grounded to the alternator bracket

 

[Hydro-idi]

Don't mean to hijack thread, but will the wix 33417 screw onto the 6.9 fuel filter header?

 

[OLDBULL8]

http://www.ebay.com/itm/OEM-Genuine-...lWeCWb&vxp=mtr

WOW, the price for that.

I've got one just like new for sale for a 1/4 of that. Pictured in post #9, which includes a new Racor filter.
I'll even delete the heater if wanted with the 1/2" NPT plug.