Greetings,

I'm trying to troubleshoot a fuel delivery issue with the truck. It worked fine, until suddenly it didn't. When turning key, the engine does not turn over though the starter works fine. I've replaced the high pressure fuel pump in engine compartment and my next guess would be the fuel level sender in the tank. I wonder though, could this simple component with no parts that I could see that could break, be the cause of a fuel delivery issue?

Any help is appreciated and thank you in advance.

-skrmisz

 

So we know exactly what we have.
What is the 8th digit of your vehicle's VIN ? Is it a "T" or a "U" The T is a 2.9 engine and the U is a 3.0 engine.

How was it determined to be a fuel issue?

 

The 8th of VIN is actually "Y"
In regards to how I determined it was a fuel issue, perhaps I wrongly assumed it is. If I spray starting fluid into the carb, it starts and runs for a second.

 

OK, you are right about the 4.9 L in line 6 cyl , not a V6, but the info I have says it is a 1987 year.
We'll eventually get this right, patience pays.
The 10th digit for a 1986 is "G" , is that what you have? The 10th digit for a 1987 is an "H"
This stuff is all important to have the correct info.

It could have a carburetor, are you sure it is a carb?

Your theory of a fuel system problem makes sense, but how we approach the 2 different possible fuel systems is very much different..

 

OK, it seems we have a carbureted engine.
The fuel pump that is bolted to the side of the engine is the only fuel pump for a carb engine.
If you remove the air cleaner, hold the choke open if it is not warm enough to stay open, look down into the throat of the carb, when you manually work the throttle linkage as if stepping on the gas pedal, you should see a squirt of fuel each time you work the linkage. If you don't see it , either there is no fuel getting to the carb.or the float is stuck preventing fuel from coming in. Are we sure there is sufficient fuel in the tank? If you tap it on the bottom and get a dull sound there is some fuel in there , if a hollow sound , you are out of fuel. The best way to be sure is to add a few gallons , then you know what is in there.
If you still get no fuel up to the carb, remove the line from the carb and crank the engine over a few revolutions .if you get fuel the pump is working . If not, the pump is not working.Some pumps with wear on the pump arm, did not get enough movement to operate the pump correctly. We always manually checked a replacement pump before install to make it was capable of pumping fuel.Lets see what you find so far.

 

Thank you so much Hanky. I have just put 5 gallons of fresh fuel in the tank, so I will try what you suggested to narrow down the problem. I'll update with my findings when I have a resolution. God bless!

 

Yes, 1987 was the first year with fuel injection on a 4.9. I am sure of that.You have a carb and a mechanical fuel pump on your 86.. Most of the time, mechanical fuel pumps will rupture their diaphrams. That will leak fuel out of the pump's weep hole and also into the crankcase, dilluting the oil. That will wipe out the bearings in short order. If your oil smells strongly of gas and could possibly be overfilled, you could have a failed pump.Hopefully, the cam lobe for the fuel pump is not worn down where the pump cannot deliver fuel.
Some things don't make sense here. You either have the year or engine incorrect. There's no high pressure fuel pump on a 1986 4.9 inline six engine.