sounds like its missing a little @ low speed until it sounds like it fouls plug

[fredejo]

1990 240 (SOHC) i've got 170K+ miles on it. it's fine on the highway @ high speed, but starts to miss a little when you are @ low speeds or idle & then gets worse (eventually sounding like a plug has fouled) until i get to higher speeds etc... already replaced plugs/wires/cap/rotor/o2 sensor/fuel filter/ looked for vacum leaks/& cleaned MAF w/ electrical contact cleaner, & cleaned all harness connections i could find. #1 injector is leaking in between the fuel rail & the injector.

1. could the #1 injector be bad & be dumping fuel into the #1 cylinder to the point where the new plug cannot fire b/c of all of the fuel, & then once i get onto the hwy for a minute or so it clears up & runs fine (maybe b/c all of the other injectors are also dumping alot of fuel @ high rpm's so #1 can finally "catch" up w/ the other 3 cylinders & starts to be able to burn the fuel again????????)

2. could the fuel pressure regulator be bad (stuck open @ 43psi @ all times) & be flooding the injectors w/ too much fuel making it run bad @ low speeds/idle, until i get to higher rpm's on the highway & then it seems to clear up. PLEASE HELP, im soooooo tired of messing w/ it i think i might just replace all 4 injectors w/ refurbished venom injectors ($34 each from nopi)