'93 YJ Fuel Injector Control problems
Long time reader, first time poster. I have a '93 YJ 2.5L with a reoccuring issue I cannot seem to solve. I've read alot of posts but still looking for some help or ideas.
My YJ will run pretty good for a few weeks at time and then, while driving, I'll notice a little stumble and not long after that the check engine light will come on. I can continue to drive the Jeep with some lack of power and a stumble through acceleration. Over the course of a few days the issue will get progressively worse to the point that I have to hammer the throttle just to get through the gears. Eventually, when I shut the Jeep off and let it sit for a minute it won't start back up. At that point I disconnect the battery and pull a plug and it will start back up on 3 cylinders (I did the first time while checking for spark). After putting it back together it will run fine for a few weeks then the problem will start all over again. The check engine light throws a "27" code each time which is "fuel injector control". I'm not sure how to check each injector other than pulling the connectors (maybe check the voltage?) which hasn't helped me pinpoint the problem and I don't know how to diagnose a bad ECM. I'm considering pulling the fuel rail and inspecting the injectors and o-rings for obvious visible damage.
I've changed the fuel filter (have good pressure at the rail), plugs, cap and rotors. Cleaned the throttle body, AIC and TPS. Also put on new cat and exhaust.
In the end, I can fix the problem as it occurs to keep driving but I'm stumped on the underlying issue. Thanks in advance for the discussion!!