5.3 bogging/stumbling
 

What's up guys ? Been lurking for a minute trying to soak up information, but I'm at a dead end at the moment with my swap. I have a 5.3 with a 670 holley on it and every time I accelerate from a red light or stop and go it stumbles like it wants to die. The carb was sitting up awhile. So, i put in new gaskets, float, accelerator pump, and a bigger squirter (31). I did notice the other day once the car gets warm up it stumbles just a little bit but not to the point I'm going 5 mph waiting for it to go. ????

Stock 5.3/LM7
MSD 6014 LS1 timing selected
TH350

Is it stumbling while getting on the gas hard or gradually getting on the gas? What is you fuel level set at and fuel pressure?

stumbling while gradually getting on the gas like just trying to cruise. I got the regulator set at 6 psi

Its a walbro pump inline.

Do you have a afr gauge? I assume not, but I would recommend one.

I'd make sure that the float level is right first. Do you have a MAP sensor hooked up? Make a reference mark on the balancer for any one of the cylinders and use a timing light just to see if it's advancing properly.

I am currently tuning a stock 5.3 as well, and in order to get it right I had to use the #35 squirter and the blue cam, needs a really aggressive shot, but right now this most likely wouldn't help if you're only gradually accelerating. Does aggressively accelerating make the problem disappear, or get worse?