1991 Seirra 5.7 ltr
Just purchased a 1" spacer and injector spacer and am curious if it's worth installing now or if I should wait to install aftermarket headers and y pipe? I have a aftermarket cat back system but will I see any results with the spacer? Looking for a bit more jam and maybe some gas mileage.

Gord7

There are huge debates about TB spacers. Most agree they don't do anything for you, others swear by them. I have a personal vendetta against those dang Electronic Carburetors (aka TBI), but i don't see why the injector spacer wouldn't do some good, but I haven't heard much about those guys. In my opinion i would hold off on the TB spacer, but go for the inj. spacer, unless anyone else has an opinion on those. I'd like to hear if it helps or not.

(or just ditch the TBI for some "real" fuel injection!! = ) )

if you have an automatic make sure you re-adjust the kickdown cable. some kits come with spacers to raise the throttle/kickdown bracket. i don't know if they help or not. i'm guessing not.

Well, I say since you arleady have them, then why not just install them and tell us how they work!!

I too would like to know if a Throttle Body spacer would help.

good point... put the injector spacer on first and see if there is an improvement and then do the TB spacer. That way you can see just how much each affected the truck.

do one thing at a time and record whether it helps or hurts. i put on a jacobs electronics coil and that made a big improvement, and also wires.

I made my own tbi spacer 1.5" thick installed on a 90 1500c/k with the injector spacer I picked up 2 mile per gallon and 2 tents in the 1/4 mile no BS just fact.

I need someone to tell me why my sons 1992 305 Chevy throttle body fuel injection motor will not idle at a constant speed if the heat sensor is hooked up

when your temp sensor is disconnected your computer sets your cars idle speed. it sounds like your temp sensor is bad. or possibly your throttle position sensor.

Mommasdog, the ECM sets the the idle speed via the Idle Air Control motor on the throttle body. The temp sensor sends a variable voltage signal to the ECM telling it the engine temperature. It then set the idle speed accordingly like a carb does with a choke. Cold engine - high idle, warm engine - lower idle. Toivo is right, the sensor is probably bad. Not expensive and easy to change...