2003 silverado, 6.0 tvs1900. Starting and driving around normal it drives totally fine. The afr seems good with 14s at idle and under load in the 12s.... Starting under boost it seems to do 5 psi then hesitate/lack of power...the afr is all over the place. The fuel pressures fine and doesn't drop. Then when you let off its back to normal. No codes or lights are on. This all is new within the last few days.

I'll do a data log and send it to blackbear, with what I have I cannot see what's going on.

 

12's in boost sounds bad, mid 11's in boost with regular pump gas is far better and less chance at engine damage. Not sure why blackbear would think that is okay, but I wonder that about a lot of what he does.

Without having the vehicle in front of me or a log file to see it's hard to get at it. Check grounds, plug condition, wire for damage and stuff like that is something I'd do.

 

Under load 12s not boost. Under boost in the 11s yea but now it starts at about 5psi and the power lacks then the afr are all over. Changing from 11s to 10s to 12s. Kind of strange, I'll see what I can come up with.

 

Sounds like a misfiring cylinder.

12s is fine fow low boost, like <3psi or so. At that power you barely have a net gain in power from supercharger sucking power off the crank.

 

Mine does this also, say im cruising along at 35-40 and ease into the throttle it feels flat and I have to almost make it kick down to get it up into boost. Not liking it right now at all!

RT

 

I think you hit it, I'm going to go thru the injector harness now where I put the new ends on. I could of bumped something putting the new tensioner/belt on. I thought tho if it was a miss fire I would get a code. It wouldn't be the tune since it was fine a few days ago.

 

I have noticed on my blower that boost is not really linear with throttle. Lets say if I just stomp the pedal it will make 14psi, but if I gently roll into it by full throttle it will stay around 7-8psi. I think this has to do with the bypass valve spring not being very strong.

 

Mine has been pretty even...the more pedal the more psi, works pretty steady. 1/2 throttle comes out to about 6-7, wot 12-13.....with no slip. I messed with the injector harness before, one wire looked to be coming out of the connector but it was hard to tell. I pushed it in more, i will know in the am if that was the problem.....i hope so, ill just change the pin.

If not Is their a way to test the injector wiring..? Like each one a certain voltage..?

 

You can test the injectors by measuring resistance across them, but the actual voltage is only a few miliseconds long at idle so it would be hard to test that way.

 

What is the timing doing in those situations???