Anyone 7.3l smart?

[WVRigrat05]

Have a friend with a 2001 7.3l 6 speed.


Banks 4", banks wastegate, 100% stock, has 35's and that's it.

When he starts it of a morning, it puffs heavy white smoke and misses, when it warms up it runs fine. No fuel in oil or antifreeze mixing anywhere.

Anyone have an idea what to look at? I'm thinking a sticking injector but I know they run off the HPOP and though it's maybe getting weak.

 

[Bustedknuckles]

Check the glow plugs. If all are good and functioning its injector time.

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[clrussell]

Check the glow plugs. If all are good and functioning its injector time.

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This is where I would go.

 

[WVRigrat05]

Anyway to check glow plugs or injectors with a scan tool like a duramax or no?

 

[clrussell]

Anyway to check glow plugs or injectors with a scan tool like a duramax or no?

You can buzz test the injectors. But that only tells you the circuit is good.


You can amp draw the glow plugs, but it doesn't tell you which one is bad.. they are dinosaurs so you gotta treat em old school.. check the glow plugs with a good old school test light. Not an led one

 

[catman3126]

How many miles? depending on how cold it is when he is starting it outside. if the relay has gone bad a 7.3 will start really hard and smoke or not start at all in the 40 deg range. if just a few glow plugs have went bad then that could be the issue. if its higher miles like 200-250k+ might as well do a set of injectors and glow plugs and a relay. world of difference..

 

[WVRigrat05]

Truck has 215k. We changed the relay in 12' at 135k so it maybe due again.

It's been in the 20-40's here of a morning.

 

[catman3126]

easy to check if the relay is bad. one of the two bigger posts is hot all the time and when you turn the key on the other once should be hot too if not that's it. its bad. I'd start there before you go after GP's

 

[clrussell]

If it's starting in 20-40 degree weather not plugged in the relay is good imo.. most 7.3s won't start at 50 or less with no relay lol.

 

[fast03]

I have heard of the upper oil gallery being clogged and not being exchanged with engine oil... maybe causing a sticking injector because its dirty

 

[WVRigrat05]

Ok, I'll let him know and go from there. He's had it since 2007 and 50k miles and it's been flawless other than leaf springs and front end part here and there.

 

[catman3126]

If it's starting in 20-40 degree weather not plugged in the relay is good imo.. most 7.3s won't start at 50 or less with no relay lol.

That's for sure lol

 

[NC-smokinlmm]

It might be stiction. The HPOP injectors get wierd with cold fuel and oil...

 

[hetzler_l33]

Just an idea for if nothing else works, knew a guy who had trouble with his truck cranking after it sat for a few hours and he replaced his harness that feeds the GPs. That solved his problem but then again I'm not sure if he checked the GPs since they were replaced not too long before that. Like I said, just a backup idea if you try everything else

 

[THEFERMANATOR]

I know the valve cover gaskets gave ALOT of trouble as the wiring harness for the glow plugs and injectors is part of the gasket. Over time the gaskets break down, oil gets into the wires, and breaks the insulation down and the glow plugs lose current.

 

[WVRigrat05]

I told him to check the relay to start. And dump a qt of two stroke oil and 100 gal treatment of fuel cleaner and see what it does and go from there.

I'll let you know what we find out.

 

[kiwilml]

It might be stiction. The HPOP injectors get wierd with cold fuel and oil...

If I remember correctly there was an article in diesel power mag a year or two back about some shop running some special additive in the oil that helped with cold starts.. I think I would try find some more info on this and try that.. Could be the whole problem?

 

[onebaddmaxxx]

Dumping additive in the fuel side isn't going to help the oil side is what has trouble.

The glowplugs can be tested to see if they work properly through the UVCH (under valve cover harness) the outside 2 pins on both sides of plug are for glow plugs. Take a voltmeter ohm between battery ground and each of those pins. Spec is 0-6.0 ohms. Anymore than that they are no good

Buts likely the injectors.

 

[skintback]

If I remember correctly there was an article in diesel power mag a year or two back about some shop running some special additive in the oil that helped with cold starts.. I think I would try find some more info on this and try that.. Could be the whole problem?

REV-X oil treatment

Helps with the morning sickness of the 7.3 and 6.0 helps clean a sticking spool valve in the injectors

 

[gmac32]

i use hot shot's secret stiction eliminator in the oil and hot shot secret diesel extreme in the fuel. The stuff works wonders. It sounds like he could have a couple glow plugs bad but I would still highly recommend the hot shot. I work on fords everyday (not by choice) and adding that stuff really makes a difference.