99 suburban misses and surges after warm up
 

my sub would run fine till she warmed up or sometimes after a restart and then the surging and missing would begin. no codes. 7000 dollar snap-on scanner told me nothing. I had a rebuilt motor. changed the distributor, ecm, the mass air flow sensor, fuel pump, tps, plugs wires, temp sensor and wire, cats and muffler were already new and for my efforts I was rewarded with hiccups and dead cylinders. NOW MY SOLUTION WAS : THE OLD STYLE POPPIT SPIDER INJECTORS WERE GARBAGE.... I installed the newer multiport injection unit and she runs like a dream. my 220000 mile sub runs like a new car again.... hope this helps someone else:).