Any suggestions in regards to use of 703 injectors and dirty plugs?
Eroded plugs, i.e. gap has increased from spec, will effect emissions and power, dirty really doesn't make any difference, but if its really filthy, oily, wet, that indicates other problems that need to be fixed. As well, arguably enough foreign matter coating the plugs could short them instead of the spark jumping, I think they have to be filthy dirty and wet for that to happen.
Keep in mind, the Chrysler EFI (Don't know on the Renix) is adaptive, it will measure how much the A/F ratio when its in closed loop operation and adjust the fuel injector pulse width to get the proper amount of fuel injected into the engine, it stores correction values that also get extrapolated for open loop operation. SO, changing in fuel injectors with a different one should NOT effect it, it should adjust to it in a few dozen miles of driving.
That is why people putting in bigger injectors, find they do NOT inject any more fuel then the OEM injectors. Obviously if you put in smaller injectors, you may need more fuel than they can supply so that would hurt you.
Where the injector can effect emissions, is the spray pattern, that can differ with injectors, and old injectors can clog up and NOT have a good spray pattern. What reduces emissions is the fuel mixing evenly and atomizing well in the cylinder. A good injector will spray the fuel in a fine mist in a cone shape that is perfectly sucked into the intake port. An old dirty injector may spray a couple of streams off in the wrong direction, have the fuel lay on the intake walls and thus won't mix well or atomize well, and thus won't burn as well either, idle can be rough, emissions go up and power goes down. And a new injector that is the wrong type, the spray cone might be off a little and instead of the entire cone of fine mist being sucked into the intake port, half of it sprays on the walls of the intake runner, reducing that best mixing and atomizing in the cylinder. So if you have people telling a particular injector didn't give good results, I'd suspect that as a cause.
I heard, and it could be dead wrong, so confirm it with some one that can confidently tell you, that the Dodge Neon Injectors are cheap, available and work well in the Jeep XJ motors.
A can of injector cleaner added to the fuel tank can't hurt. Chevron Techron seems to be the best, most people swear by it, and there are more than a few that are a joke and don't do anything.
One other thing to keep in mind, use the Octane fuel recommended for you motor. Using higher than recommended octane gets you nothing at all, the thing is about higher octane, it is less volatile, meaning it doesn't evaporate or atomize as well, if your motor was designed for 87 Octane and you're using 93 Octane, that could make a difference in how well the fuel is atomizing and burning completely. In fact its been show in many motors designed for 87 octane and the owners were using 93 octane, they experienced stalling with a cold motor in below freezing weather. (Having said that, the higher octanes usually are a higher quality base stock with different blend of additives, so it wouldn't be shocking to see someone say they smog tested with low octane and high octane and happened to get a better result, that varies greatly with area, engine and all sorts of factors).
arty:
