wide open throttle problems. i'm new and im stumped.

[$500hoe]

ok i have a 98 tahoe 350 vortec. it has 167000. now i replaced plug,wires,cap,rotor,coil, fuel and air filter, used acdelco plugs, altenator. now under full throttle it just doesnt want to rev. it acts like a miss but its not. it runs perfect, idles great. 1/2 throttle it runs very smooth. but if i pull out to pass it just doesnt have power. it will do this in park to. if i rev it up it is fine until i open it wide open it doesnt want to rev. now i cleaned everything mass air flow and throttle body. i noticed today when i sprayed throttle body cleaner in the intake tube. it revved great. like i opened it wide open and it didnt miss a beat. no stumble. when i quit a few minutes later it was back to acting up. my gas mileage sucks. like 9 mpg. i get about 230miles out of a full tank. and there are no codes. i have had the beast for about 5 months. and it basically has done this the whole time. please help!!.

 

[99_2door]

does your tahoe have the factory tune in it?

 

[$500hoe]

ya its all stock. i only have a k/n and a flowmaster 40 muffler with stock exhaust. nothing is altered. also it has a new battery too. and when its cold cold it doesnt want to start. you have to crank a few times. esp. in the winter. but once its warmed up it starts on the first hit. or if the battery is just a bit low it will not start. i'm at a loss right now. but i know it will run right cause when i had my 200 amp charger on it while it was running it doesnt studder at all. it will rev the whole rpm range wide open.

 

[retorq]

IAC or TPS??

Does it throw any codes??

When you say you spray cleaner in, rev it and it's OK that makes me think you have an air leak somewhere ...

 

[$500hoe]

nope no codes. i was leaning towards the mass air flow reading off @ w.o.t. or air temp sensor. because the throttle body cleaner made the plastic pipe cold. so the sensors would pick that up. but any other vehicle i've used it on made it run like crap till the cleaner worked thru the system. this motor is spotless and doesnt make a squeek or sound. it idles perefect and there is no hesiation. my only other thing is why would it run good only when i put 200amps from the battery charger. i just found out about the cleaner today. i just want to be sure before i put more money in it. i already did all 4 shocks , inner and outer tie rod and sleeves and 4 universals. and when i bought it the reason i only paid 500 for it was the tranny was out. i put one in it that cost me 150. it shifts and pulls like a dream. plus brakes and rotors and drums too. i have about 1100 tied up into it including the hoe it's self. i just dont want to have to put too much more if i dont have to.

btw i also unplug the mass air flow and ran it down the road. it didnt deem to act up as bad. it just would come to idle abit different. but it actually seem like i had more power. but i could be dreaming it. i want to pull a camper but i cant if i can get on it to make a hill.

 

[steamroller]

Have you checked the fuel pressure? Sounds like a fuel delivery problem to me, probably the fuel pump or the infamous spider poppet injectors acting up