My 454 Rebuild

[Supercharged111]

The black box does not seem to report knock retard.
I don't really want to put the 0411 back in yet as i don't want to introduce more potential problems.
With either ecu on the old engine it did idle perfect and never a miss. Problems started with the new engine and i still suspect a bad cam.
Once the fuel pressure is fixed it's about all that's left. I have checked or replaced about everything else!

A bad cam would have a valvetrain tick to it. The black box does report KR, just a matter of whether or not Torque will play ball with it.

 

[Spareparts]

I might need to mess with it then to see if i can get KR working.
By bad i mean ground wrong.

 

[Supercharged111]

I might need to mess with it then to see if i can get KR working.
By bad i mean ground wrong.

Ahh, well, you could always just map the cam without yanking it. Measure IVO, IVC, EVO, EVC, duration and lift.

 

[Piratehunter]

A bad cam would have a valvetrain tick to it.

please expand on that.
I've got one exhaust valve that sounds out of adjustment, then quiets for a bit after warmed up, then comes back, quiets again. I pumped that cylinder up, took the spring off, looked ok, not broken, put back together and adjusted. same over.
it was doing this prior to me having the intake off. looked at the lobes then, didn't notice anything or wear unusual.

 

[Spareparts]

Most times a bad cam means missing a lobe or more causing loose valve lash.
Sounds like you have a weak lifter.

 

[Supercharged111]

please expand on that.
I've got one exhaust valve that sounds out of adjustment, then quiets for a bit after warmed up, then comes back, quiets again. I pumped that cylinder up, took the spring off, looked ok, not broken, put back together and adjusted. same over.
it was doing this prior to me having the intake off. looked at the lobes then, didn't notice anything or wear unusual.

This was the bad cam I bought my truck with. Couldn't hear the valvetrain over the squeaky belts.

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As you can see, a couple valves had excessive lash.

 

[Mangonesailor]

Can just the pump be replaced. Anyone have the part #?

96/97 Fuel pump replacement tutorial (with bed cut)

This is a tutorial for replacing the fuel pump in a 1996 and 1997 GMT 400. I'm pulling out a Spectre (that I put in while stranded this week) and putting a new Delphi in (replaced under warranty!) First, I did the bed hatch cut per this thread by shelbyt.67 ...

www.gmt400.com

Also, I'm not sure dash command or Torque ever reported KR to me when I had my black box. There USED to be a PID for it, then I think they made some sort of plug-in? Not 100% on that, but around that time is when I got HP tuners.

Which,

would really be a lot more helpful troubleshooting. It'll be a little disheartening because there's a hot-restart issue that comes with that, but it's something in the base tune I've been chasing for a while. Even @BNielsen has the issue, and several others with a base tune from Lextech.

So, I know you're having fuel pressure issues so you're on the right track. One thing that would also be worth checking is the actual IACV counts and see if it's around 40 (that's pretty ideal. I think the book says maybe 35-50). I believe dash command is what I used previously to get that right, but I had a 0411 then as well and it was chasing a p0300 misfire code.

My truck makes maximum vacuum at idle with 18*, because that's what I've tuned it to do. 24 sounds pretty normal, cause it's all about emissions and stuff. Yeah, you're going to only get about 14* when accelerating just like with a vacuum advance dizzy. Engine vacuum drops when you open the throttle, so the vacuum lowers, thus less advance. This is to mitigate spark knock and ping. I think the highest I go in my truck even when it's in power-enrichment is around 17-18, and that's even chucking gas down it's throat. Our intake air charge just gets WAY too hot though to really have a lot of advance and make power low in the RPM range.

The black box (with BB tune) spark table looks like this:

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This is mine, but it doesn't show spark correction for PE mode and IAT and other stuff.

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[Supercharged111]

You need more WOT advance yourself then. While the big blocks don't gobble up timing like a small block, teens is laughable for a stock motor.

 

[L31MaxExpress]

You need more WOT advance yourself then. While the big blocks don't gobble up timing like a small block, teens is laughable for a stock motor.

I tried to put 2* in my buddies 99 K3500 crew cab and it had knock retard, so I pulled it back out.

 

[Supercharged111]

I tried to put 2* in my buddies 99 K3500 crew cab and it had knock retard, so I pulled it back out.

My truck took mid to upper 20s, though with the blower it's less than 10. Seems wrong, but pulls hard.