7.3 idi problem

JackAsserson

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Tank selector valve? These are notorious for failing.
Water separator? Mine is near the brake booster. Not sure if your truck came with one. They are known to fail/leak.
Shower head(s)? These are the fuel pickup ends in the tanks. They can fall apart, or off, and you'll be sucking air if your fuel is starting to get low. Add more fuel and then you'll know.
Running off boat tank again with no problem. The tank is definitely full. The shower head could make sense.. I may just get a 50 gallon tank in the bed and run a line to the pump
 

JackAsserson

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I can run off boat tank to get her going, then swap to factory line and it’ll run fine for awhile, until it gets air
 

JackAsserson

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There is a separator right by the booster with a shader valve on it. I assume that’s the separator at least. I am about to run to the part store and grab something to bypass that selector switch. Any idea what size the feed/return are? Guessing 3/8 and 5/16
Is the fuel tank selector valve still connected?
Is there a water separator present?
 

Old Goat

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Correct, Supply is 3/8" and Return is 5/16" fuel line.
If your year truck has the factory Water separator next to the Brake Booster, and has not been by passed. You can use a double Barb 3/8 fitting and connect the 2 hoses together.


Goat
 

Old Goat

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Sizzle is an excellent descriptor for the sound lol
If it does not sizzle, it could be corrosion where the Cord plugs into the Block Heater.
When I bought the 86 lil over 10 years ago, the Cord was in pretty bad condition.
Bought a new one off E-Bay for $20 or so. Worked perfect.
Put some dialectrical grease on the pins.
Living in the rust belt, the salt does wonders.




Goat
 

Brian VT

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Correct, Supply is 3/8" and Return is 5/16" fuel line.
If your year truck has the factory Water separator next to the Brake Booster, and has not been by passed. You can use a double Barb 3/8 fitting and connect the 2 hoses together.


Goat
Don't try to purge the water separator. If it wasn't leaking before then it likely will if you mess with it. Bypass it. At least until you isolate your problem. My bet is on the fuel tank selector. That was my problem. I've been running on just the front tank since then. I gotta deal with that some day.
 

JackAsserson

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Don't try to purge the water separator. If it wasn't leaking before then it likely will if you mess with it. Bypass it. At least until you isolate your problem. My bet is on the fuel tank selector. That was my problem. I've been running on just the front tank since then. I gotta deal with that some day.
I think you’re right on the money, I looked at it and it looks like it never been replaced, covered in mud. We will find out here shortly
 

JackAsserson

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I’m trying to fix the truck and stick on my ranch to use a couple times a year running to the blinds/ fill feeders. One tank will be fine for that
 

chickenpot

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I’m trying to fix the truck and stick on my ranch to use a couple times a year running to the blinds/ fill feeders. One tank will be fine for that
your best option of deleting the selector valve is to pick one of the good tanks, and run brand new rubber fuel line from the pickup to the lift pump, and from the return tee back to the tank. this will shore up hopefully any air problems. you would be better in the long run if you dropped the desired tank and inspected the pickup and for sludge.
 

JackAsserson

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If this doesn’t work I’m just going to stick a tank in the bed and run it
your best option of deleting the selector valve is to pick one of the good tanks, and run brand new rubber fuel line from the pickup to the lift pump, and from the return tee back to the tank. this will shore up hopefully any air problems. you would be better in the long run if you dropped the desired tank and inspected the pickup and for sludge.
 

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