This weekend I put a new crate motor in...All went well but now it will not start..It will sit and turn and turn and will not start..

I have replaced coolant temp sensor, CPS, waterpump, ignition coil, new plugs, wires, cap rotor, fan clutch, CCV/Vacuum parts, and I think that's about it.

When I pull a plug and watch it spark I get a single spark and then nothing at all.. Basically the spark is intermittent.. I am at a loss as to what it could be and hoping someone can help.

 

Did you utilize your existing flywheel?

 

Yes I did use the existing flywheel..

Just some added info..This is on a 91 XJ 4.0 engine...

 

With my experience on rebuilding 4.0's...sometimes it takes quite some time for the lifters to pump up...does it sound like you are getting compression? Or is it just free spooling?

 

did you use old electronics or new electronics?

 

Kyle, When you say electronics do you mean sensors? If so I have changes the CPS, Coolant sensors, O2 sensor...I am going to take the starter, alternator and battery down to get tested tomorrow..

89xjgrey, Yeah I thought about that but the motor has been dyno tested and had oil and water ran through it by the shop that built it..Also I have tried and tried to start it..It just keeps turning but never seems to fire up. Has intermittent spark as well..

Now though I get nothing..no turn over or anything...headlights work and that damn annoying buzzer works other then that nothing else works...I have checked all the ground points and they are as they were before swap..I took some good pics so I could compare to be sure..

 

Fuel pressure?

 

Have you looked into the possibility that the cam position sensor may be bad or loose. My timing was off 180 degrees on my crate engine, and my cam position sensor was faulty. Mine is a Renix and may be completely different but that would be my next thing to check.
Good Luck, let us know when you get 'er fired up!

 

I am going to replace the cam position sensor today....We'll see if that works or not..atm though even when I turn the key I get nothing so it won't even turn over now..

 

Nothing in the ignition side controls that. If it won't turn over then you have other problems besides the ignition.
Blue

 

Yeah when I turn the ignition it just doesn't do anything..almost like the starter isn't engaging or something so time to start with that and work my way back to the ignition..

 

Check all your grounds first. The battery ones and the block to body ones. Take a jumper cable and ground it to a motor mount or something substantial and put the other end on the negative post of the battery and see if you get a response when you try to start it. That will tell you if the ground is, in fact, the problem.
Good luck, grounds very often are an XJs biggest headache.
Blue

 

Ok it turns over I had just done something goofy...anyways...Anyone have any idea on how to disassemble the distributor in order to replace the cam position sensor?

 

Pull the cap and rotor and there it sits. Two screws IIRC and out it comes. Reconnect the wire from the new one and put the two hold down screws back. Then re-install the rotor and cap........voila! DONE

 

Wish it was that easy...remove the 2 screws on top and you have another plate ontop of the sensor and don't know how that comes off...