jhand

Hey guys,
I need help fast. To start off with I purchased a used 01 Cherokee Sport about a month ago. At the time of purchase, the guy that sold it said the the original 4.0 engine went out and he replaced it with a 4.0 from a 98 model. The engine itself only had 95xxx on it. The body showed 165xxx. The cel was not on and the jeep ran good at the time of purchase. Around 2 days after purchase I got a rough idle and threw a cel code that was P0301, which is a cylinder 1 misfire. I immediately ran seafoam in the fuel and put some in the intake and I put new plugs in it, (the old plugs looked fine, no oil or coolant) and then I cleared the codes and within half an hour of new plugs the code came back. So then I said screw it and put a new coil pack on it, that is when the real problems started. After the new coil pack the cel started flashing and the jeep was acting like it wasn't getting fuel. It would rev up normally in park but with a miss but as soon as I put it in drive it started acting like it wasn't getting fuel, it would struggle to reach high rpms, although it would catch at times and rev high with a horrible miss and sputter. If I was going down the road I would place in neutral, shut off and back on and it would run fine besides a miss when you stop. It only seems to do this when I'm cruising at 1500 rpms or lower. Then I was like screw it high mileage I will start replacing sensors. New TPS. New crankshaft positioning. New oxygen sensor, new cam shaft sensor and none of them helped. So I was like ok I'll put in new upgraded fuel injectors, the upgrades have 4 holes instead of the single hole. Still no good. I'm not losing coolant, my oil is staying up and good. I'm about to lose my mind. I'm going to try to get a compression test done however if it is the block i thought I would be losing coolant or the plugs would show something. I'm at a complete loss. There are times this this happens I do show a multi cylinder misfire. Any suggestions? I will check and make sure that the plug in the coil pack is good and tight. Also I don't know if this makes a difference but during the miss I unplugged #1 injector and no change. Could it be the rail that the injector plugs come from? Help is needed. I purchased this jeep as a go to work vehicle because my dodge trans went out. Please help!