injectors from a 86-92

[tamalpro]

do they fit on my Mr-2? those are the 540 right? i think so but im not shure.If so, if i put those injectors on the Mr-2, do i have to tune or something?

[clem]

89-93 turbo mr2's never came with 540 injectors they came with 440!

[tHa kNiGHt FaLL]

you do not increase injectors unless you increase spark. you do not increase spark unless you increase cylinder size. you do not increase cylinder size w/o doing cams...

any single mod doesn't make a difference. do them all at once and your going in the right direction.

toyota knew wha they were doing when they built the motor. you add fuel w/o anything to compensate your computer is going to read rich and adjust its long term fuel trim to compensate. your computer needs to know what size injectors and in an OBD I car its not easy or cheap. includes replacing the PROM or getting a fuel management system.

ultimately the answer to your question is yes... you need to tune and change parts with it.

[meoggi]

you can increase spark without doing anything else. you wount get alot more out of it but you have the potential of getting a more complete burn. why would you want to get a cam? a cam allows more fuel and air into the combustion chamber. why would you want to do that when your not burning everything in there to begin with.

[tHa kNiGHt FaLL]

you wouldn't get shit from increasing spark..... toyota designed the ignition system to burn all the fuel in the chamber. a stock ignition system can handle more than it puts or anyways. you'd be using all you reserve all the time and you'd have no dwell and your coil would wear faster. without more fuel to burn more spark is pointless.

a cam increases air in and air out.
bigger cam meaning duration, slope, and valve overlap = more air in and more out.

an engine is a giant vacuum... it sucks massive amount of air in... and pushes massive amount out. you want performance you increases the amount of air in each intake stroke and match it with the amount leaving. then be able to speed up that process using more fuel and more spark which is needed when more air is being used.

i said if you do it... do it all and at the same time. thats why kids who thinks because they are on a budget they'll do one thing at a time and get to all of it down the road but end up having all kinds of ignition or fuel issues. too much fuel can cause detonation... wrong spark timing or burn angles can cause preignition... all bad for the motor... do it all at once and make sure all the fuel gets burned at the right time.