RUNAWAY! RUNAWAY!

[JLDickmon]

RUNAWAY! RUNAWAY! (UPDATE!!! stoOpId truck!!!)

not RUN AWAY!

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although I am SERIOUSLY thinking about lobbing the Holy Hand Grenade at this thing...

OK... here's the story.

Over the summer a friend blow'd a head gasket on a '95 K3500 4WD stick... so I spent a couple Sundays and a couple more days extracting a broken headbolt yadda yadda yadda...

anyway... fast forward to a week ago.. calls me up, says "I hear a clattering noise and it's running like crap"

and when I get there, it's also dumping loads of black smoke... OK.. rough run + black smoke = fuel injector. Sounds good? OK.

I'm driving it home tonight to my place to do the injector surgery... all of a sudden, this thing is blowing IMMENSE CLOUDS of grey smoke and it's straining HARD against the turbocharger and DOES NOT want to slow down when I release the throttle...

luckily, it's a stick, and the clutch is stronger than the brakes and I get it DOA alongside the road in a cloud of smoke and a hearty HI-HO SILVER...

any guesses?

failed injector caused it?

FI pump is trash (does have known issues)?

pump timing all outta cattywampus?

I drive a SuperDuty, so this is a tad bit foreign...

 

[tonkadoctor]

Runaway is caused by injection pump failure....... or being caught near a broken natural gas line. Only 2 things I've ever seen cause it.

 

[JLDickmon]

that's what I was thinking

thanks for the confirmation.

Injector pumps aren't too bad... only about $1,100. bucks...

 

[chrisk1500]

IP is toast...

 

[JLDickmon]

GM still recommending replacing all 8 injectors when you do a pump?

by the way, this is the same truck from this thread

 

[chrisk1500]

That used to be the case when they had steel rollers in the pump....now they are ceramic....not an issue anymore...

 

[JLDickmon]

I forgot to post the update...
here's what happened
the miss was not an injector as first thought.
one of the bolts holding the rear rocker shaft broke, and it spit a pushrod...
that's what caused the miss

Unfortunatley, I didnt catch this untill I had the new pump on and the new injectors in... out of box, you own them.

the runaway was actually caused by diesel fuel filling up the crankcase and getting sucked back in the intake...

I was surmising that the runaway filled the crankcase with diesel...

gas motor pro, diesel motor rookie.

anyway, all is well now...

 

[JLDickmon]

stoOpId truck (POS)

this POS...
did it again.
only on the other side..
I never saw anything anywhere in any service literature saying rocker arm bolts were one use, or torque-to-yield...
but this stupid thing broke another set of them, only on the right hand bank..
(where you have to remove the turbocharger to get to the injector lines)

***!

Anyone ever had this trouble?

guys, I'm NOT a rookie at engine repair.. I know my way around.
These bolts don't come anywhere near the bottom of the hole, so they can't be bottoming because of a crushed rocker shaft...
They're busting right where the threads engage the head (about four threads down from the shaft),
and they are more or less shearing clean (no twisting)

These bolts are suffering fatigue and need to be replaced at a certian interval (which I don't remember reading),
are torque-to-yield and are one-use (again, don't remember/cant find anything to contrary)

***?

This truck is definately cutting in on my fishing time.

 

[chrisk1500]

They are not TTY. Not sure why they are busting on you....bad luck?

 

[JLDickmon]

....bad luck?

valid explanation when you're talking about me..

has something to do with that big glowing "Born to Lose" tattoo that appears every now and then...

 

[Brimmstone]

Don't feel too bad. I've heard of this happening to a couple of other 6.5s from that era. I've also fixed one myself. From what I've seen and heard the general consensus is the bolts were weak. We pull tested an old one on the truck I fixed and it snapped almost instantly. I don't remember where we got the replacements at but we pull tested one and it held till our little homemade rig broke. As of last night the old horse is still running just fine