Fuel heater is probably bad. It could be loose or just bad seal, but that is unlikely to just start leaking there. Usually after having messed with it and accidentally leaving it loose is when that happens. If you see it coming out right where the wires are- definitely bad.
So, while you have it out of the truck to replace the heated, this is the time to replace the 3 rubber fuel lines going from the ffm (fuel filter manager). All diesel now days has alcohol in it (ethanol/ methanol). It didn’t used to when these trucks were built and the fuel line doesn’t stand up to it. And the amount of the alcohol is being increased in many areas. So don’t just buy regular fuel line. Get sae30r9. I suggest new hose clamps at same time.
Next things to consider:
Many learned that larger size line and fittings from the ffm to the ip helps the truck run better, especially because of the under powered lift pumps we have. This is known as the FTB mod (Feed The Beast). Drilling and tapping the ffm, 3/8” line going out to match incoming and the fitting on the ip (injection pump). If you dont want to drill and tap yourself, there is a ready made kit with brand new ffm including new heater and filter. This isn’t needed, but can be an improvement.
Heater:
FTB fittings and hose kit:
Complete ffm with FTB done already:
leroydiesel.com
Next thing to consider in this area is a fuel pressure gauge. Read why before dismissal. This might have you not buy any of the above parts.
A new injection pump will cost you about $2,000 if you diy AND have the computer to time the new one, or you have to buy that also.
There are 3 reasons an injection pump die -
1.worn out at 250,000 mile range.
2.Water/ fuel bugs in the fuel- can happen anytime.
3.low incoming fuel pressure.
On the water: used to be if your water in fuel light came on, you would drain it, then second time drain and replace filter- but with the alcohol in the fuel now- drain and replace filter every time now. There are better water separators available.
The factory style lift pumps are not great, but the great ones cost a ton of money. Some like Fass have an amazing water filter that will hold a lot more water than than the tiny amount ours will, has a better filter, better pump, and a screw in better heater as an option. If you are not afraid to invest in the truck because you know you will stick with a diesel long term- this is a better option.
This fits the buy once/cry on e lifestyle rather than replacing the cheaper ones every hear or so, or the medium price ones every 5-6 years.
The pressure. Your incoming fuel pressure should be 8-14 psi. Leroy sells an affordable tap fitting that goes on top of the ffm if you stay that route. It measures fuel pressure coming into the filter. This is an ok option and way better than nothing. I prefer using a metal T fitting at the ip that you can attach the gauge to via sending unit or metal line.
You need to buy the gauge itself and mount in the dash so you can see it while driving. In diagnostics in the shops, we have to run the gauge against the windshield under the wiper blade to see it gets ok pressure while under hard acceleration, so just under the hood gauge doesn’t help. I used to use mechanical gauge with a metal fuel line feeding it- but now would recommend an electric unit for ease and safety.
You will spend a couple hundred bucks doing this probably. But knowing you are distressing the expensive injection pump before you ruin it is huge. Also, at some point in the future you will have engine troubles. There are 2 things that are always checked first in diagnostics on these. What is the fuel pressure to the ip, and is the return line clear of bubbles and contamination.
The $5 and 5 minute improvement.
That clear line- is the last part of this book of recommendations (for today anyways). Go to any hardware store and get 1/4” clear tubing. It is sold by the foot, usually made of perfectly clear pvc. Get 2 screw style hose clamps to fit it. Cut the line in half, and save one half (out of the sunlight, heat, and cold) to be used in a few years. Replace the existing return line coming out of the front of the ip near the thermostat housing. It is like an upside down ‘U’ shape and is the only 1/4” fuel line at the front of the engine.
This is so you can see fuel flow whenever the key is, watch for debris in The fuel, and for bubbles. Bubbles indicate air is getting in the line and can cause all kinds of crazy running issues.
So if you are driving and ever have anything funky going on- you just look at temp and oil pressure gauges like normal, then at the fuel pressure gauge. If all that is ok- pop the hood and look at the clear line. I can’t begin to tell you how many times in diagnostics the first thing that has to be done is add a fuel pressure gauge and clear line- then drive the truck and watch for it to happen again.
These diesels are old and diagnostics is different than new ones that 99% is done through the computer. Doing these two things- gauge and clear line are well worth it imo.
Let us know how the fix goes and if you have any other questions or issues.
Also once this repair is done- come back to learn what stuff to check to keep it alive longer - especially if you have not read the library info yet.
