hobit

I have a 99 XJ that will not spark(it is the 4.0 liter). To give some back ground on the problem, I got it from a auction, at one point it ran just fine. Then come the day of the sale it would not run. I still got it thinking that it was a quick fix. Looked at it and found out it was not getting fuel. So I replaced the fuel pump, now I am getting fuel just fine. As I looked into it more I found out it was not getting spark. I thought it was the ignition coil, replaced that and still not go. I looked at the wires going to the ignition coil and it did not have power going to it. So I thought there must be short in the line somewhere, when I would unblock the two ground wires that are under the ignition coil I would get 6 volts to the ignition coil. I started following the wire back through the wiring harness, got so far and gave up on that. So I just went over by the air filter and found the wire there and say that it had 5 volts to that point. So I cut into that wire and ran a new on the rest of the way to the coil and now have 5 volts to the coil (I am thinking it only needs 6 and that 5 will be ok, let me know if that is wrong) the jeep will still not start. When I check the ground wire it does not ground out. But before I go through the wiring harness again I went to the same place where I got the power from for the positive side and checked the wire there. It still does not ground out. So I was thinking that the ground is a pulsing ground. So I cranked the engine and checked the ground at the same time and still no ground. I am thinking that ECU is bad, but before I go and buy a one I wanted to see what you guys had to say. I check the ignition switch by turning on the heater and then trying to crank the engine over to see if the heater turned off and it did. Any other ideas on what I can try?
Thanks

TrekkerJmm

Hi and welcome to CF from Tj in NJ. I believe the pulsing ground on that side of the coil is correct but I think your problem may be the CPS (crank Position Sensor) if you do a search on this forum you should find what your looking for...Tj
PS I sent you a PM...