Well I think I might need new injectors for my 305 but soon(within the next few years) I will be putting in a 350 TPI, and it also needs new injectors. So what I was wondering if I got a set of 21# injectors would these work on both engine setups?

 

I would go for 22's on the 305, and 24's on the 350, the system will work better if the ECM knows what injectors are installed instead of having to fight with the O2 sensor to adjust out the the increase in fuel flow. A slightly larger injector will run cooler because they'll run in less than the 80% max duty cycle, preventing semi-static flow (50% duty cycle) which causes a lean condition.

 

Thats the thing, I dont want to buy 2 sets of injectors. Since my car is running pretty good now do you think the original injectors will get me another 50,000 miles? Or is there no way to tell.

 

Stock injectors are designed to give you at least 50,000 miles. If your injectors are stock, and you have more than 50,000 miles on them then you've already gotten your money's worth.

The following isn't the best way to do it, but it won't cost you any thing except your time. If you're experiencing idle hunt, or stalls this would be a good time to clean the plemum and Throttle Body expecially the EGR passages, do the Minimum Air/TPS/IAC adjustment procedures.

I would pull the plenum off, raise the fuel rails up, put a large jar under each pair of injectors (wide enough to center each injector to allow you to see the spray pattern,) and with the coil to distributor spark wire removed (don't disable the Dizzy because the ECM will disable the injector pulse) disconnect one injector of each pair, crank the engine for exactly 30 seconds, and compare the amount of fuel each injector flowed, then do this to the others, and again compare them all. Do this again only to look at the conical spray pattern, and inspect the fuel for contamination (like water,) if there's no abnormal patterns, or flowrates then you probably can go another 2, or 3 years on them.

 

21's will be fine.

 

Hey. Mkos1980,

My 388 is 6.4L. Your 383 show 3.8L, what did I do wrong? Does 3.8L indicate volume, or something else? If that's your engine volume it must get really good MPG, can you tell what you did to get that combo?

 

lol thats the motor in my Grand Prix. Look one up Its next to my formula lol