How can ya tell the difference between a TBI and a MPI engine. I have an '89 4 banger but when I bought it the seller showed me a carfax report saying the engine was replaced. I donno if whoever replaced it put in another 89 4 cyl or if they went with a newer 4 cyl. The difference between the TBI and MPI for me is the addition of performace excessories such as throttle body(and spacer), air intake, avenger supercharger.... Thanks.
P.S. feel free to give me any ideas in getting more power from those 4 angry squirrles under my hood.

TBI has the fuel injectors over the top of the throttle body, and MPI has one injector at the intake runner of each individual cylinder. There are a few things you can do to get a little more out of the squirrels, like exhaust upgrades, throttle body upgrades, and even gearing, but don't expect miracles. The 4 cylinder will put out more horsepower than the old 4.2 six cylinder, but where it is lacking is in the torque department. Torque is not as easy to make as horsepower. Hope you enjoy your new Jeep. Take care...Mike <img src="/forums/images/graemlins/oink.gif" alt="" />

Mike the Mod is really good at breakin' it down. The difference between Throttle body injection and Multi-Port is right there for you. One thing that he might not have made clear is that the only way to get your "four angry squirrels" happy is gonna cost you your nuts. <img src="/forums/images/graemlins/lol.gif" alt="" />
They should never have put a 4 cylinder in a 4-by, IMHO.