First_Formula

So the bar that goes through my throttle body that the throttle plates are bolted on to had a bunch of play in it, figured i'd get a new throttle body. L03 stock throttle body is 250 dollars new and there isn't one in a junkyard in this whole state. I grabbed a 350 throttle body from a junkyard that had no play and was much smoother opening and closing but looked virtually the same other than the angle the throttle plates sat at during closed.

I put that on my car today (the TB unit came with injectors in it, TPS and the IAC all still in it so i left them all in and plugged them in) Turns out that the 350 throttle body I got is missing one vacuum line on the right side of it but it was plugged on my old throttle body anyway,
But to the point now its idling at 1200 rpms and it's got this weird rev echo bullsh*t going on like if i tap the gas it'll rev up to 1500 go down to 1450 when i let off the gas then then rev to 1650 1700 kind of thing and usually hover there and sometimes slowly hover down.... sometimes..

Anybody have any ideas? Idk what that vacuum line was supposed to be attached to and the only other things i can think of is the new IAC is set for more gas for the bigger 350 motor it came on or the injectors themselves are the 350 60/lb/hr injectors and are spraying more and keeping the idle up but that doesn't explain the ghost rev...

I have no idea guys, please help lol

ex-x-fire

Did you use a new gasket? You can try to switch over the iac. Unhook all linkages from the tbi & see how it idles, maybe one is holding the throttle open.

jim_in_dorris

350 injectors are 10% bigger than 305 injectors (more fuel) so I would not be surprised that you have an idle problem, it will also run rich.

dspencer24

iTrader: (3)

sounds like a vaccume leak, but i dont know that much about tbi, My throttle body had a leak did the same thing, but i think my tps did the same thing, put your tps and iac on there see if that helps

UnderCover89TBI

iTrader: (25)

overfueling could deffinately be a problem

First_Formula

So lets say that im a complete idiot and dropped on of the big O rings for the injectors into my throttle body while i had the plates open... If i start the car will the suction of the exhaust pull it through the piston and out the exhaust or am i looking at ripping the engine down...

Update,
decided to try starting the car anyway and i put the old injectors back in and now they're spraying like absolute crap, just dripping and kind of sloshing. theres a semi cone shaped understructure but mostly just crappy sloshing and it sounds like its putting far too much gas in.... These injectors worked perfectly when i pulled them out yesterday, anybody got any ideas?

henryd3

iTrader: (128)

You might want to check out the fuel pressure regulator. Easiest would be swapping out the one on the new TBI with your old one. May want to replace the diaphragm while you're at it, or that could be the problem on the one on there now. Could also try setting the base idle and IAC as shown in this article from the technical articles section. Lots of good stuff in there
https://www.thirdgen.org/tpimod2 Hope you got another O ring

First_Formula

I got another 0 ring for the injecto yeah, also i switched out for the old fuel pressure regulator and that didn't help any. One injector sprays a mist (I cant tell wether its a fine enough mist or not) but the other one is like i described and its too damn cold out and i don't have a garage to do this is so my patience for fixing it is shortening ever so steadily lol.

Next step is just try all new gaskets and see if that does anything then new injectors.

Thanks for the link to the idle setting thing! I've been trying to find out how to do it lol

henryd3

iTrader: (128)

Well, you can try swapping the connectors on the injectors and see if the problem stays with the injector or the wiring and that would at least tell you if the injector is the problem or not. Not all that much help though...