01 f u 550 hard starting, "White Elephant"

5

56cummins

Member
Bought the truck in August off a car lot. 208k miles, crew cab 4wd. It fired up easy, pretty quick, ran good. The exhaust manifolds were not warm to touch, probably run earlier in the day. When October came, the truck was slow to start, runs rough for about 10 minutes, then runs great. Now that it's as cold as a witches tit in a brass bra, the turd won't start for an hour. It seems like the injectors are loosing prime as it sits. Any advice is welcome.

I put a 4.1kw starter on it, it spins like crazy now. It's a DB off amazon.

2 good batteries, the glow plugs pull the volts down to 11.9 before I crank it.

Did an injector buzz test, nothing an untrained ear can discern.

Fuel pump is pushing fuel, new fuel filter in the engine valley. Didn't check psi.

Fresh oil right after I bought it, I was hoping fresh oil would clean up the slow start, rough running. No such luck. Oil is 15w40 Harvest King, black as coal after 20 minutes. I regret not sucking the injector oil sump out.

What are the chances a stiction oil would help this?

Any advice is welcome.
 
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Glow plug solenoid and intake heater solenoid. Wouldn’t hurt to pull valve covers and check continuity on glow plugs. 10-30 for oil in extreme cold or full synthetic 5-40.
 
I know they are pulling amps, but I should check every glow plug.

I'm more concerned with the lack of cylinders in the first 10 minutes of running. My cummins starts on 3 cylinders in 18 degree weather, but is popping on all 6 within 7 seconds.

That's a good idea, check the cranking compression while I check glow plugs.
 
Look into a block heater if you have an outlet for electricity. And yes, check every glow plug. A single failed plug will effect starting. Those 7.3 are cold cold cold blooded.
 
56cummins said:
Bought the truck in August off a car lot. 208k miles, crew cab 4wd. It fired up easy, pretty quick, ran good. The exhaust manifolds were not warm to touch, probably run earlier in the day. When October came, the truck was slow to start, runs rough for about 10 minutes, then runs great. Now that it's as cold as a witches tit in a brass bra, the turd won't start for an hour. It seems like the injectors are loosing prime as it sits. Any advice is welcome.

I put a 4.1kw starter on it, it spins like crazy now. It's a DB off amazon.

2 good batteries, the glow plugs pull the volts down to 11.9 before I crank it.

Did an injector buzz test, nothing an untrained ear can discern.

Fuel pump is pushing fuel, new fuel filter in the engine valley. Didn't check psi.

Fresh oil right after I bought it, I was hoping fresh oil would clean up the slow start, rough running. No such luck. Oil is 15w40 Harvest King, black as coal after 20 minutes. I regret not sucking the injector oil sump out.

What are the chances a stiction oil would help this?

Any advice is welcome.
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Sounds like you're losing prime. Might be at one of those short sections of rubber hose or the fittings on the lift pump. Clean the engine's valley and check for wet spots(that's what she said) after a while. Buy a boat load of cheap 10w-30 diesel oil and change the oil every 500 miles two or three times; it'll look like new inside. Don't bother with changing the filter until you're ready to put the good oil back in. And yes, run thinner oil in cold weather for just about any HEUI fuel system equipped engine.
 
My dad had a 7.3 that got hard to start, then eventually wouldn't start at all. I ended up removing the plug in the high pressure oil pump reservoir and manually filling with oil. It would drain all the oil out after sitting over night.
 
Sub'd.

As a "new" 7.3 owner have realized through interwebs research there are a shitload of o-rings that can leak on that engine causing a multitude of issues.

Check the GPR and glow plugs to ensure they're working correctly. Could also be the EPBV, but I don't think that would affect start up, just running in cold ambient temps - read - white smoke control.
 
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I'm dang sure not a Ford or 7.3L guy, but everyone one of my buddies in OK that have had starting issues have always fought it until they replaced all the glow plugs and solenoid. $.02
 
I've had a couple that I've DD'D and used to pull in the 2.5 classes between Illinois and Indiana. we still have 3 that we use on the farm regularly
Since 2005 i've been replacing glowplugs , GPR, AIH and batteries every 5 years per truck just to help avoid hard starting situations. Some might say its unnecessary but its worked for us. If i know a truck isn't going to be needed for a few weeks and its winter, i'll put the trickle charge on it.

But the winters here in illinois aren't nearly as bad as others.
 
Wire a trickle charger into the block heater plug and mount it under the hood. Then when you plug the block heater in, the batteries get charged at the same time with one cord. If you don't need one, you probably don't need the other. I've always meant to do this and have never got around to it.
 
Update with no wrenching done. Ran the truck yesterday, last run at 9pm. Sat all night at 24°, fired up on the first try at 8am. Started on 6 cylinders, good bit of white smoke. I'm going to check the hpop reservoir next time it sits for a couple days.

Thanks for the help gentlemen.
 
56cummins said:
Update with no wrenching done. Ran the truck yesterday, last run at 9pm. Sat all night at 24°, fired up on the first try at 8am. Started on 6 cylinders, good bit of white smoke. I'm going to check the hpop reservoir next time it sits for a couple days.

Thanks for the help gentlemen.
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Don't forget to account for thermal contraction when you check oil level.
As mentioned above, 5-40 synthetic is a great thing in a HEUI engine that sees cold temps.

Also, I personally have a strict no ether policy on 7.3s. Their bottom end isnt exactly B series cummins like.
 
First thing I would do after covering oil level, base engine oil pressure while cranking(the sensor is in the top of the reservoir so if the reservoir is draining back for whatever reason, faulty check valve, are leak exc, you won’t have base engine oil pressure while cranking), cranking rpm’s in excess of 250rpms, both batteries, connections and grounds ok, glow plug relay connections and operation, glow plugs are all working, on a long crank no start is hook a scan tool to it to see if actual icp aligns with desired. If the ecm is seeing 12v and the engine is cranking above 250rpms, the icp needs to be a minimum of 400psi to start. If you do not have this and you have a good ipr. Then I would make sure the stc fittings aren’t leaking, the fuel line orings aren’t dry rotted and allowing air in loosing prime in the heads, but with those miles, typically there is an injector issue. You can try the oil additives&Maybe get lucky.
 
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we just did the injector shim kit on one that wasn't starting cold. works great now. they had already put new glowplugs and relay in and that didn't fix it.
 
mhuggler said:
Sounds like you're losing prime. Might be at one of those short sections of rubber hose or the fittings on the lift pump. Clean the engine's valley and check for wet spots(that's what she said) after a while. Buy a boat load of cheap 10w-30 diesel oil and change the oil every 500 miles two or three times; it'll look like new inside. Don't bother with changing the filter until you're ready to put the good oil back in. And yes, run thinner oil in cold weather for just about any HEUI fuel system equipped engine.
Click to expand...

mhuggler is on to something there. Check the stems pipes from the HPOP to the oil rails. Very common the seals go bad or the pipe itself cracks on the seem. If thats all good, a injector could be letting pressure by or the HPOP is bleeding back. I can stress this enough, a quality oil filter is necessary for any Ford. NO FRAMS, i have seen too many engines nuked because a Fram filter self destructed and sent paper throughout the engine oil galleies. Fram used to be good but they have sucked recently.
Unrelated to mhuggler, also check to make sure your crank signal is strong. Ohm out the crank sensor and check connections.
 
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