Mark where the distributor is in relation to the block then slightly loosen the 2 bolts that hold the disributor start the car and warm it up the rotate the distributor clockwise / counter clockwise until it sounds like its running its best then tighten the 2 bolts again. I have a timing gun too but i never use it. If you think you have a sticking valve do a compression test. If you find a cylinder that is low pour a tablespoon of oil into the cylinder through the spark plug hole and re do the commpresion test for the cylinder. If the pressure comes up then you have worn cylinder rings as the oil you poured in helped to seal the rings and increase the pressure. If the pressure remains low then you have worn/stuck valves. You don't have a MAF our cars use an AFM
non-pro shot in the dark... -need to set idle/timing then the tps. ...the TPS is a proven PITA to set. ...make sure the car is fully warmed and the fans are not running when you do the timing. iirc you need to have the jumper wire in and one of the vac lines plugged/capped. -sounds like a timing/tps problem (most likley). if not id go valve issue. (sounds like intake backfire)
So what your saying is the tps can mess with the air and fuel ratio? also timing for distributor is in the middle of the brackets that you can adjust it with from what ive seen in pictures of 3sge's mines in the same spot. i would like to open the timing cover and find the timing using the timing light so ill try and find a manual for it online. ill keep the thread updated with the results.
afm is probably getting an incorrect signal from the "upgrade". this is used in conjunction with all the other sensors to determine timing and a/f ratio. i think youve found the culprit. -iirc i read here that the distance of the afm from the intake manifold also has to be correct to recieve the proper signal. -id get it back to stock via junkyard airbox, re adjust everything. then ditch the hot air intake youve got. -if you want an upgrade just a simple k&n panel filter in the stock box would be better than whats on there. 09 has one and it works great. -warm up your car and stick your hands behind the fans when their running if you want to see how much hot air your engine is breathing with that setup.
