problems with the vortec tpi
okay, here is what i got and what i did:
i have an 87 iroc and i bought it with a tired 305 tpi, that the owner told me was a built 350.(this is back when i really did not know the difference.)
any way the cam went flat and i changed that out with a stock replacement or something i cant remember. while i was in the engine bay i decided to look at the casting numbers just for giggles....and it turned out to be a 305. after running in to many other problems i decided with a little peer pressure to build a motor and swap it in. so i got a 76 350 block and crank, machined them to .40 over and bought an engine rebuild kit accordingly. got the hyperutectic (flat top) pistons among the other stuff. i bought a crane cam (flat tappet) out of jegs for a 350 tpi with the 3.73 rear end( something else i was told i had that i did not, i got the borg warner 9 bolt or something.) any way i put roller rockers and the vortec heads with the sdpc vortec intake manifold. i bought 21 lb injectors for it and all this is in the motor now, i am about to get an adjustable fuel pressure regulator for it. so here are the problems: the car has a tough time starting, i have to try to start it twice and on the second time when it actually starts it runs really rough for a minute and then catches up. i usually let it warm up for a minute or two and then start driving( as it is i only drive it to work and back no where else for now. work is only about a mile or two away.) the car runs like crap for about the first five minutes of driving no matter how long it warms up, and then about half way out of the neighbor hood it sort of kicks in running a whole lot better, but still not that good. then sometimes while driving at about 1000 or less rpm the motor will hesitate then catch up, hesitate then catch up until i give it just a little more gas, also i just got it back from a freind that is really into tpi's he messed with the computor and now it still has all of those same problems plus some. the brakes hardly work( like there is a vacume problem or something) and when i go up a hill i go to give it a little more gas and it is like it has a governor, no matter how much i push the pedal nothing happens very seldomly will it even downshift and when it does it is not much of an improvement... (oh yeah the motor is broken in to it has bout 1000-1500 miles on it back when it ran a touch better, took a long time to get that seeing as how i never drive it, i didnt do any freeway or anything like that nice easy miles.) I need help does anybody have any suggestions or has anyone run into these with this setup?
i have an 87 iroc and i bought it with a tired 305 tpi, that the owner told me was a built 350.(this is back when i really did not know the difference.)
any way the cam went flat and i changed that out with a stock replacement or something i cant remember. while i was in the engine bay i decided to look at the casting numbers just for giggles....and it turned out to be a 305. after running in to many other problems i decided with a little peer pressure to build a motor and swap it in. so i got a 76 350 block and crank, machined them to .40 over and bought an engine rebuild kit accordingly. got the hyperutectic (flat top) pistons among the other stuff. i bought a crane cam (flat tappet) out of jegs for a 350 tpi with the 3.73 rear end( something else i was told i had that i did not, i got the borg warner 9 bolt or something.) any way i put roller rockers and the vortec heads with the sdpc vortec intake manifold. i bought 21 lb injectors for it and all this is in the motor now, i am about to get an adjustable fuel pressure regulator for it. so here are the problems: the car has a tough time starting, i have to try to start it twice and on the second time when it actually starts it runs really rough for a minute and then catches up. i usually let it warm up for a minute or two and then start driving( as it is i only drive it to work and back no where else for now. work is only about a mile or two away.) the car runs like crap for about the first five minutes of driving no matter how long it warms up, and then about half way out of the neighbor hood it sort of kicks in running a whole lot better, but still not that good. then sometimes while driving at about 1000 or less rpm the motor will hesitate then catch up, hesitate then catch up until i give it just a little more gas, also i just got it back from a freind that is really into tpi's he messed with the computor and now it still has all of those same problems plus some. the brakes hardly work( like there is a vacume problem or something) and when i go up a hill i go to give it a little more gas and it is like it has a governor, no matter how much i push the pedal nothing happens very seldomly will it even downshift and when it does it is not much of an improvement... (oh yeah the motor is broken in to it has bout 1000-1500 miles on it back when it ran a touch better, took a long time to get that seeing as how i never drive it, i didnt do any freeway or anything like that nice easy miles.) I need help does anybody have any suggestions or has anyone run into these with this setup?
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