416 won't pull past 5800

[Hemi2slow]

My friend has a 2000 TA with an LS3 stroked to a 416 in it. We're running the car with the 2000 computer. Car has ported L92 heads, custom cam and is on approximately 11.3 compression. The VE table is good and the AFR is 12.98 right up untill 5800, at that point it goes to 19.0, backfires and dies. Its only on 18 degrees of timing. Our tuner couldn't find anything wrong when he tuned it. We've tried a crank relearn and that didn't help. Could there be something in the tune that should be done different for the large motor that maybe we all missed including our tuner? Oh, I believe the car has 42 lb injectors and it has been tuned speed density. Thanks in advance for any suggestions. I'll try to upload the tune tomorrow when I can get internet access with my laptop.

[mrfister77]

You might check the fuel pump (pressure, volume etc.)

[smithers]

Tune? Scan?
what is your injector duty % at?

just a guess... 42's might not be enough, or pump starving as mrfister77 suggests.

[5_Liter_Eater]

MAF Patch?

[Hemi2slow]

Gonna try and get a tune and scan file posted this evening. We had thought that it might be fuel pump starving but its not a gradual loss of power like you'd expect. Its an instantaneous shut off. When we first put it together we had trouble with it only firing on 5 cylinders. The crank sensor waveform was whacked out so we changed the sensor and it went to running on all 8. So we're beginning to think it may be another problem with the crank sensor or reluctor wheel. Thanks for the replies.

[Sherminator]

What does it have for a reluctor wheel, crank sensor(color?) and cam gear(1X or 4X).

[Hemi2slow]

It has a 24 tooth reluctor wheel and a stock ls1 crank sensor. I'm not sure about the cam gear.

[cornerburner27]

Being new to tuning, I unfortunately can't offer any help. But I would very much like to see the tune after the problems are resolved. I am building a 416 stroker for my car as well.

[FastEddy]

This thread is pointless without files! lol