I swapped out my old TBI with a "rebuilt" unit off ebay.

The new unit seems to work great except when the engine is stone cold if I simply turn the key (don't touch the gas) the engine will start but will usually die or barely run...unless I touch the gas a little, then it seems to come to life and be just fine after that.

I'd like to be able to reach in and start my car without touching the gas pedal and have it start and be normal. What could this be?

I noticed the new Throttle Body had a different arrangement of hose connections on the front. I think I have them hooked up o.k. but the MAP sensor port was in a location that didn't allow me to use the factory-formed vacuum piece so I've use a length of rubber hose.

Any ideas?

 

Kind of sounds like an idle air control problem. but once it starts its fine?

 

could be ur idle control sencor, its a little motor with a screw in type valve, the motor rotates and adjust how much air it allows through the little hole , if its bad then its not opening fast enough for the motor to idle so maybe thats why u need to hold ur gas pedal a little open until the sencor opens up. Remove ur air filter and unscrew the sencor from the TB, and check it out, here in case u dont know wich one is it, its the one circled in red.

 

i agree its probably a IAC issue, but check out this thread; you may just need to make an adjustment to its setup:

https://www.thirdgen.org/forums/tbi/...djustment.html

 

what was the original problem?

is the motor in good tune?(recent plugs,wires,cap,rotor,air & fuel filter and timing set?)

plug in a scanner and get some base readings,tps,cts,iat,iac,etc.

dont just start replacing sensors.

 

Yeah, sounds like you need to set the IAC and base idle. Here's a tech article from the technical articles section( lots of good stuff there) you might check out
https://www.thirdgen.org/tpimod2
Oh, and remove the clip before starting engine

 

Thanks guys for all the ideas.

Yes after I give it a little gas, then it is fine while I'm driving stopping etc. It is just starting and staying running if I start it without touching the gas pedal. Basically it seems I have no high idle.

Without giving it gas it will always start...but barely. It usually stumbles and dies. Sometimes it will stay running but it always seems like it is just on the edge of dying very low rpm. But if I give it a small stab of the gas pedal she roars to life and then purrs like a kitten form that point on. However...never seems to have a high idle...just normal.

The reason I swapped out TBI units is becuase my last TBI idled WAY too high (and had 220k miles on it) I figured since everything else is basically new, including the engine, I might as well put on a freshened throttle body. the seller on ebay said they were tested for fuel pressure etc so I thought it might be a nice upgrade.

However other than eliminating the really high idle at start up, (now it is too low! go figure) I can't really tell any difference from the new throttle body. I might just put the original back on the high idle might have just been a vacuum leak from tb gasket.

 

Much much easier to set the Iac and idle first to see if that fixes it, but hey it's your car

 

You're right, I'll give it a shot. It would be great if this solved the issue and I could keep the newer throttle body.