hey guys i have searched for this for about 2 days now and my ? is i have a 90 iroc with the 305 tpi what injector size are they from factory aned what is a good injector size to go to with out hurting the engine i mean with out needing more mods than the basic stuff thanks for your help

 

Welcome to TGO. There's a lot of help and info here, sometimes finding it can be half the battle.. In your quest to learn more about your car and the TPI system, rather than supply you with the answer I'm adding a link to a site you should go to and read up on. There you'll find many answers and lots of useful help aids without lots of .02 cent opinion. Good luck

http://www.chevythunder.com

 

A for "305 TPI injector size" didnt find anything? They're 19lbs injectors. For a stock engine, leave them alone. 19lbs is just fine. You wont need bigger unless you put in nitrous, a blower, or put in a bigger engine.

 

well i thought the 19lb injectors where orange or something mine are black and silver i am trying to find out because my car runs really rough once it warms up it will stall out while driving when you come to a stop light

 

Get an ohm meter and measure the resistance of each injector. They're supposed to be more than 14 ohms when cold or warm. Anything less than 12 ohms when warm and its a bad one.

 

ok thanks i will do that today that could cause it to stall at a stop light right because i also have that problem when it gets warm and then come to a stop sign or stop light if i dont hold the idle up a little then it will stall

 

ok i ohmed the injectors and they all ohmed out at 16.4or 16.5 so i say they are good i checked the plugs and they are all gapped at 35where they should be so what else

 

Did you check them hot ? I just replaced mine yesterday with Ford injectors and wow, what a difference.
The stock ones suck a$$

And 15.8 to 16.6 is the actual spec

 

cold they where ranges from 16.3 to 16.5 but what size injectors did you use and where did you get them from

 

I used 19lb FMS injectors (OE is 19lb in a 305TPI)

 

i take it they just plug right up or do you need a wire harness

 

100% drop in replacement

 

hey do you have the part number for those 19lbs

 

397-M-9593-C302 i think

 

ok thanks i will try them