Zepe63,
You either have a lack of spark or lack of fuel problem. If you have access to an timing light then hook it up and see if it lights when you are cranking. If not then you know for sure you have a bad CPS. If it does light then that does not elimate a bad CPS.
You can try unplugging the CPS from the engine harness, the plug is very close to the temp sensor in the head. You will find it on the driver's side of the block around #6 cylinder. Sometime unplugging and replugging fixes the problem for a short period of time.
You may not have enough fuel, you can test the fuel pressure in the line to see if you are holding pressure and if the pressure if hight enough. There is a check valve in the fuel pump that goes bad. You could have a bad pressure regulator which also is letting the pressure bleed off or not regulating it to the right pressure.
There is a sensor in the distributor which tells the injectors when to fire, this replacement is best accomplished by installing a new/rebuild distributor. This sensor is called the camshaft position sensor. You have to pull the distributor to change the sensor, if you have it out you might as well renew the distributor also so the new/rebuilt distributor is the way to go.
You need to check for spark and fuel. The problem is there no consumer priced tool for us to check out out engines. The Snap-on tool runs $2000 to $2500. My guess is you need to replace the crankshaft position sensor (CPS).
You can get two versions of the CPS at the dealer, the normal and the high altitude. The high alt gives you more advance which means more power. The difference between the two is where the sensor is mounted on the curved piece of steel. The high alt is off center, the normal one is centered. I got more power I could feel out of my 4.0 once I installed the high alt model. NO worry about pinging since the engine has a knock sensor, I think every renix XJ should be running the high alt CPS.
Martin
