1999 454 Vortec misfire issues

[L29Sub]

If deleting the EGR, you've jumped the shark already. Why not carb it? Go simple, very dependable, easy to tune and easy to diagnose and repair if needed.
It'll get good mileage and you can forget about all the "almost perfect" tunes. Save BIG bucks!
You will need a stand alone TCM or manual trans. Any similar year pickup donor will offer manual components. All bolt in.

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[Saab84mw]

Found my misfire issues:

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[PlayingWithTBI]

Glad you found your problem. I don't think a carb would've helped that, LOL.

 

[Saab84mw]

Went by the The engine shop today To check on the progress of the rebuild.
They have finished with a line boring of the block it’s OK the crankshaft needed to be replaced it was too far gone and he also handed me my camshaft which was in a lot worse shape than I originally thought.
And with five bad lobes that would be my running issues.
Earlier concerns from others were an issue with the cam gear or the distributor but it seem to be good.

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[Mangonesailor]

Earlier concerns from others were an issue with the cam gear or the distributor but it seem to be good.

Yes.

You probably would've figured out you had a deeper internal issue sooner if you'd taken a look, but at least now you're getting a fresh motor.

 

[1998crewcab]

What wold cause such damage ? Not enough oil lubricant or failed lifter ?



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[Scott Martin]

Found my misfire issues:

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I'm having the same problem and I was hoping to find an easy solution but this doesn't give me very much hope.. I guess I'll just drive it until she blows up or I can afford to get something else!

 

[Saab84mw]

I'm having the same problem and I was hoping to find an easy solution but this doesn't give me very much hope.. I guess I'll just drive it until she blows up or I can afford to get something else!

I was chasing this issue for about 4 to 5 years and kept throwing parts at it
If I had just taken the intake off down to the lifters I would have noticed the issues.
But as they always say hind sight is most of the time 20-20.
I keep posting so maybe it will help someone else.

 

[Saab84mw]

Getting ready to put the engine back him any suggestions on the type Of Coolant to switch to I was using dex-cool before my engine went.

 

[BeaverBill]

Getting ready to put the engine back him any suggestions on the type Of Coolant to switch to I was using dex-cool before my engine went.

I had similar issues with my 99 Sub 7.4. I limped it into my garage and shut it off, it refused to start after that. It sounded like some wires were crossed when I cranked it. Timing chain and distributor were replaced by a reputable garage 2000 miles back. No codes. I changed the crank position sensor which came out in 3 pieces but no change. I changed out the cam position sensor and nothing changed. The icm was next but that wasn’t it either. Cap and rotor looked good. I then changed the coil. Now I brought the engine to tdc #1 and pulled the cap again, I think I invented some new names for GM’s engineers. Rotor appeared to be pointed somewhere between #1 and #8. It looked like I could turn the distributor far enough to line things up. I did this and installed a new cap for good measure. It started right up. Strange that it ran for a couple thousand, was a bit boggy at times and then quit. Twice the check engine light came on but cleared before I got home and never any codes. Hope this may help someone, it would have saved me some money.