So,
I have a whole series of problems that might be all one thing, or just bad luck piling up.
It took me a while to figure out just what was going on (and of course, I could be wrong). I'm running on WVO with a two tank system, and a while back I discovered I had the veg filter on wrong, so I had a big messy leak on the engine, so it took a while for me to figure out that in fact, I have a leak on the stock/diesel side too.

Now that I've removed some of the other possible variables, it seems like I've got a leak from (or near?) the air temp sensor deal -- the sensor that is behind/underneath the fuel injection.
The truck has been running really hot (going uphill in 4wd, as I have to do to get to my house) even with an empty bed.
I also seem to be having trouble with the transmission- that it seems like it's not shifting into 4th as though I have the overdrive off... which could be a whole separate issue, or maybe the air temp thing is screwing things up?

- could fuel be leaking from there, or is it just splashing on there from somewhere else? (it's not a fuel line,btw)
- would replacing that sensor fix the leak?
- could that bad sensor be messing with my shifting?
- am I crazy?

Tys

 

Can you explain that a little better?

The injection pump?

 

Yeah, I'm not understanding what sensor you're referring to. Can you get us a pic?

 

yes, sorry. I'm an idiot. I will get the manual out tomorrow and be more specific.

 

this 'thermistor' is at about 7 o'clock to the fuel filter when looking at it from the driver's side.

my manual says it's installed in the intake manifold... could it even be the source of my leak?

and yes, I checked to see if I screwed on the fuel filter properly. twice. and I have a drain tube on the bottom of my water-in-fuel sensor/separator that goes down past the axel, so I know it's not junk coming from there.

it sort of follows that bad shifting and running hot could be symtoms of the wrong air temps, doesn't it?

Another weird symtom: when it gets real hot, my speedometer starts jumping all over the place, whether I'm going 2 or 25, it bounces from 0 to 50.

Tys

 

It sounds like the fuel heater is leaking, it's right above the fuel filter. It is held on by the stud the filter screws onto. There is a quad-ring sealing it to the cylinder head. If you live in a warm climate, you can get a shorter stud and omit the heater.

Do a search for "fuel heater", lots of reading.

 

I'm with the Cap'n on the leaky fuel heater gasket. Since you are running veggie you need to keep the heater, though.

On the OD/speedo issues: Check to make sure the VSS is tight and that the wiring is in good shape.

 

I did a very scientific test today, where I put some cardboard in next to the engine and turned her on. The leak is coming from the area behind the fuel injection pump... sort of where the brass lines come out. Of course, it's ridiculously hard to see back there, so I'm not sure exactly.

Now, 'rumor' has it that running veg oil is harder on these pumps, so it's not unbelievable that this thing is crapping out... and wouldn't that sort of explain my loss of power (aka seeming like it's straining in 3rd on the highway) and overheating?

If I figured out how to get a wrench down in there, to undo and redo those connections, besides putting air into the system, am I up for any other surprises?

Tys

 

So I was reading some more on here, and found this thread about the speedometer and overdrive issues.

Could this be where my power issues are coming from? god, that would be great. Of course, I ran over to my truck this morning and starting looking through the service manual, I can't find where the connection is between the speedometer and the transmission. where the heck should I be looking? (of course I don't even know if I've got a cable or the electrical deal. The manual says electrical)

Where's this 'speed sensor' that I should replace?

barking up a lot of trees now...
Tys

 

It sounds like the seal between the pump head and the case is leaking. That would explain loss of power.

Your speed sensor is located on the transfer case.