These are 17.5lbs injectors off a S50. Popular upgrade for your M20 for better higher rev acceleration (5000 RPM +), smoother ride, and still retain great gas mileage!
Easy to install, it should take less than a hour.
"Factory injectors are barely adequate to even feed a stock motor when they're new, chances are they aren't feeding enough fuel above 5500 any more. You will want to upgrade your injectors before doing any other upgrades. Any other worthwhile modification will max out your stock pieces and be theoretically useless. Cheap replacements include stock pieces from an M50/S50 motor (E36 2.5 and 3.0, rated 17.5lb/hr) and Ford V8 (Mustang/Crown Vic/etc, rated 19lb/hr). Either set will do the same thing, but using the M50/S50 ones is a little easier because they are all Design II type, meaning the fuel sprays out of 4 pintles instead of 1. Better atomization."
Easy to install, it should take less than a hour.
"Factory injectors are barely adequate to even feed a stock motor when they're new, chances are they aren't feeding enough fuel above 5500 any more. You will want to upgrade your injectors before doing any other upgrades. Any other worthwhile modification will max out your stock pieces and be theoretically useless. Cheap replacements include stock pieces from an M50/S50 motor (E36 2.5 and 3.0, rated 17.5lb/hr) and Ford V8 (Mustang/Crown Vic/etc, rated 19lb/hr). Either set will do the same thing, but using the M50/S50 ones is a little easier because they are all Design II type, meaning the fuel sprays out of 4 pintles instead of 1. Better atomization."