1988 f350 6.8 idi

JackAsserson

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I believe it’s a 6.9.. not sure.
I was told by previous owner it died while driving (no bog down, quickly shut off)
There’s only one tank, no selector valve. Tried running it from a boat tank, still no fire. I don’t believe it’s an air issue, I bled the injectors, they seem to be getting fuel, but I’m not sure if it’s enough.

I hear a quiet click from one of the solenoids on the IP , the other solenoid (closer to the cab) produced no click. Which one is the FFS? Closer to bumper or cab? And can I run a hot wire to both of them? It’s hot here today , so I don’t think glowplugs are the issue. No smoke coming out of exhaust
 

JackAsserson

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Just noticed this round thing next to the IP with another spade connector on it. Wired into the same harness as the spades on the IP. What is this?
 

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rreegg

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Stock ‘88 is 7.3L. Even if warm out should be worth trying GPs or a block heater if there is one
 

IDIBOBS

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If the injectors are getting fuel then it’s the injectors them selves or the glow plug system. Short of a massive engine failure.
 

JackAsserson

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Stock ‘88 is 7.3L. Even if warm out should be worth trying GPs or a block heater if there is one
Unfortunately no block heater. I don’t hear any clicking from the glow plug relay when turn key on
 

JackAsserson

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Forgot to mention, the fuel pump was bad. Possibly what made the truck stop running to begin with, it’s been sitting right at a year
 

Cubey

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Just noticed this round thing next to the IP with another spade connector on it. Wired into the same harness as the spades on the IP. What is this?
The cylindrical thing with the rod poking out is cold idle advance. These will typically start without that working. I wouldn't worry about that, at all, at least right now. That won't stop it firing up.
 

JackAsserson

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I took off the dirty air filter, stuck rag with very small amount of gas by intake, fired off. Then hooked it up to factory tank w little fresh diesel, it’s running off of it. Idle is rough, shaking a bit, idle is up down not steady, but it isn’t stalling.
 

Cubey

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I took off the dirty air filter, stuck rag with very small amount of gas by intake, fired off. Then hooked it up to factory tank w little fresh diesel, it’s running off of it. Idle is rough, shaking a bit, idle is up down not steady, but it isn’t stalling.
You might try taking out on the highway and give it a good run. Use additive like power service in the diesel. make sure it's over 1/4 full or it may stall on a hill.
 

MtnHaul

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The unsteady idle might be due to air intrusion in the fuel system. Hopefully the air purges and the engine can at least run steady but further investigation may be required. Like Cubey suggested, give it a good "Italian tuneup".
 

IDIBRONCO

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Which one is the FFS? Closer to bumper or cab?
The FSS is the one that's closer to the cab. If you look, the wire that goes to it is a little bigger diameter than the other wire.
And can I run a hot wire to both of them?
Yes you can, but the one closer to the bumper is the timing advance to advance your timing while the engine's cold. You don't want that activated all of the time.
It’s hot here today ,
I'm kind of jealous. It might have gotten up to freezing here today. After a week of 50+, it seems pretty cold even though it's still early February.
Stock ‘88 is 7.3L
Yes it is, but a 6.9 can be put in it's place. You can tell by looking at the engine serial number, but sometimes the 6.9 or 7.3 at the first part of it can be hidden by the IP gear housing. You can also tell by the head bolts. The 6.9s have a 7/16" 12 point head, while the 7.3s have a 1/2" 12 point head.
 

JackAsserson

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The FSS is the one that's closer to the cab. If you look, the wire that goes to it is a little bigger diameter than the other wire.

Yes you can, but the one closer to the bumper is the timing advance to advance your timing while the engine's cold. You don't want that activated all of the time.

I'm kind of jealous. It might have gotten up to freezing here today. After a week of 50+, it seems pretty cold even though it's still early February.

Yes it is, but a 6.9 can be put in it's place. You can tell by looking at the engine serial number, but sometimes the 6.9 or 7.3 at the first part of it can be hidden by the IP gear housing. You can also tell by the head bolts. The 6.9s have a 7/16" 12 point head, while the 7.3s have a 1/2" 12 point head.
I was under the impression the earlier 88s could have a 6.9 but that’s good to hear. I’m going to Italian tune up now
 

JackAsserson

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Update on this truck: becoming a bit of a hassle. Truck shut off on factory tank, I bypassed the selector switch, no change. Dropped the tank, cleaned it, ran an entire new fuel line to the lift pump, looks like the fuel is full of air. I bled everything, hit the schrader valve while cranking for a long time. Wouldn’t start, walked away, came back 20 minutes later , fired right up. Ran for 10 mins, shut off, wont start back up. I don’t see any leaks in the return lines, and I don’t see how a small leak in return could cause that much air intrusion.
 

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