Hey guys. First post here. My sophomore year in high school (2009) a 2002 xg350 was donated to our auto program to work on. It needed headgaskets is what I remember. The class above mine did the headgaskets and a valve job on it. Put it back together and no start. I worked on it the next year and I swapped the cams on it because we figured they mixed them up. It fired and ran for about 2 seconds. Fast forward a few more years to now, a few more kids have worked on it and still no start, still sits in the shop. I'm good friends with the shop teacher still and I go back quite often. A few days ago we got talking about the car and long story short, I bought it for 300 bucks. Shop teacher said he is 90% sure it will start now because he finally put the cams in where they needed to be, Just needed to be put back together. I spent an hour and put it back together and you guessed it. No start. I checked to make sure everything was plugged in and all looks good. Cranks but wont start. No codes that I read, and wont fire on starting fluid. I have no idea where to look now. I'm not sure if it ran when it came in, but I remember hearing something about it needing a crank or cam sensor. I remember replacing one or the other, but that doesn't mean the new one wasn't bad. Crank/cam sensor comes to mind now but wouldn't that throw a code? It's been a few years since I've worked on something like this, I'm used to turning bigger wrenches, so bare with me haha. Can anyone give me a suggestion? Thanks, Kyle.

 

Wow, are you getting spark?

 

Well I've had a few weird problems with it. I was getting spark, but I keep losing it. I actually got it started 2 days ago though. Turns out the throttle body wasn't opening and I wasn't getting air. I pulled the intake off and was checking for spark and it fired up. Scared the crap out of me. But now I lost spark again. When I do have spark I am getting a constant 12 volts at the coils while turning it over, but when no spark it fluctuates like mad. Starts at 12 volts and while turning over it jumps between 3-5 volts. Not enough to spark. What would cause this? I've replaced the ignition failure sensor just to see. And another thing I've noticed it that little black condenser for the coil harness has about had it. Most the wires are broke off. Could that have anything to do with it?

 

I would check voltage going to ign. Failure sensor. Pin 4 pink with blk tracer according to schematic. Is the failure sensor oem or aftermarket? You need to verify battery voltage to see where your losing it. You said have 12 volts at coil at times then 3 to 4 volts. When this happens see if you have the same result going to ign. Failure sensor. The failure sensor gets voltage from under hood fuse box. I have seen burnt terminals on these cars but not on this circuit. You would have to remove fuse box top to take a visual inspection. Also need to check ground wire g11 mounted behing throttle body on firewall. This is ground for ign . Coils and ign. Failure sensor. I tried to copy and paste schematic but won't work. Try these few things and see what you get