Hi, I'm Masto from Finland. I bought a project car last summer; Jeep Grand Cherokee 4.0 year model 1994, the car did not idle. However, I moved the car by driving to my home yard when the distance was about 20 km. The trip went well when I didn't have to use idle speed. The previous owner had replaced the distributor cover, rotor, spark plugs, ignition coil, crankshaft position sensor, but the idling still limped. I started to examine other sensors, because they were not within the given limits, I only checked the following parts: Map sensor, throttle position sensor, idle air control valve, I also checked the PMC wiring harness with a multimeter, it was fine. Cleaned the ground points of the system. The idle was still limping, the revs cruised, and it didn't take more than a few revs before the engine began to cough. I suspected cylinder compression pressures. In addition, someone from the valve lifter was making a noise. I removed the cylinder head of the engine, sanded the valves and renewed the lifter. I made sure the preload was correct, measured the compression pressures, the result was 10-11.5 bar, so very good. I started the engine, the mechanical sounds were good, no sound from the lifter. But the idle was still not good, the revolutions varied between 500-1200 rpm. I revved up, the engine coughed and died. No longer started. I found a faulty camshaft position sensor to replace. Engine started fine, still bad idle, can't hold revs. At high revs, the engine shut down again, and again the cause was a damaged camshaft sensor. I replaced the oxygen sensor because I found it to be faulty. I thought I had to act now, but the same thing happened again. The camshaft position sensor was damaged again. I am helpless in front of this problem. What breaks a camshaft position sensor? I believe that the problem is not in the supply of gasoline, even though the engine cannot handle the revolutions, gasoline comes from the nozzles. I haven't measured the fuel pump pressure yet. It's winter in Finland, and I don't have a garage at my disposal. But in the spring, the plan was to continue repairing the car. I have measured the voltages of the sensors with a multimeter, the nominal voltage of 8V should go to the camshaft, measured 7.3 V (the engine does not run). I would think that the breakage of the sensor is caused by a voltage spike, but what causes it. Can someone help me? Is the PCM faulty, I've read that capacitors can cause strange faults. In my car, the engine fault light works, the codes work and all the gauges work correctly. Does anyone have experience with a similar problem and could help me with this problem please.I