LS engine problem

[cutlassmann]

hello what do it means when your riding around 70mph and punch it and it back fire through the exhaust and it hesitate to pull thanks.

[andrewb70]

hello what do it means when your riding around 70mph and punch it and it back fire through the exhaust and it hesitate to pull thanks.

Sounds like it is lean.

Andrew

[cutlassmann]

the only way to fix it is to hook it up to a dyne?

[andrewb70]

the only way to fix it is to hook it up to a dyne?

No. A good tuner should be able to tune it without a dyno. It sounds like a drivability problem.

Andrew

[cutlassmann]

what should my fuel pressure be since I'm running fuel injection

[andrewb70]

what should my fuel pressure be since I'm running fuel injection

LS fuel systems are designed to operate at 58.5 psi.

Andrew

[cutlassmann]

It's at 60 psi when running

[cutlassmann]

Could this make it run ruff and hesitate burnt wire but not all the way through.

[reschke18]

The burnt wire would cause a miss on that cylinder. Couple things to check: Make sure you don't have any vacuum leaks. Worn out vacuum lines or if one has come loose will cause it to run lean on wide open throttle because the sensors go into open loop on WOT and therefore will not compensate for the extra air. Also, check your fuel flow not just your pressure. You can buy a gauge that has a button on it to flow fuel through the gauge. When idling or with some throttle (in park/neutral of course) you can push the button and flow out fuel into a cup, and it should produce quite a bit rather quickly without affecting the idle quality or a drop in rpm. This can be a more comprehensive fuel system test. One more thing that has happened to me, on early LS motors, the computer cared about the type of fuel you were running. Not sure if later ones do... I had my tuning set for "non oxygenated" aka no ethanol. This was fine until they decided they could put up to 10% ethanol in without telling you at the pump. I tested fuels and knew where I could fill up and not get ethanol. Until one day when I had absolutely no top end power... I mean none. I tested their gas again and found about 5-6% ethanol, which is just enough to make the computer think it is adding enough gas, but we all know you have to add more fuel to make the same efficient power with ethanol. It was running very lean and set SES codes in the computer for running lean and cylinder misfires. So I had to reprogram my computer to accept the "oxygenated" gas, and haven't had the problem since. Hope you fix it!!

[cutlassmann]

It runs great it was that plug thank you for your help!!!