89 XJ help

[Jake Jacobson]

Hey folks my son has a 89 XJ that he is having some ignition problems with. The deal is this thing had overheated and then sat for about 7 years before it was given to him for a build. We're not getting any spark out if it right now. It has a new coil, ignition module and distributor, Power to the coil, nothing off the plug wires at all. The crank sensor also checks out. Just trying to get it running for now and see what we have with this thing. Anybody have any ideas on what to look at from here. Anything you can do to help out on this would be very appreciated.

 

[Bart]

I know it sounds like a broken record, but I'd go back to the CPS and hard wire the connection and see if that helps. I had to do that on a 90 I had.

 

[Jared]

What have you done to it so far? I ask because it may be helpful to know what you've had apart and put back together. When I rebuilt my 89XJ motor, I accidentally hooked the power plug for the electric fan into a sensor plug and fried the computer. It took me SO DANG MUCH WORK to figure that one out.

I'll second the CPS... I'd even swap it with another junkyard CPS to verify it's good. No spark on an old Renix era XJ is typically the CPS. Also test your plug wires, in particular the one from the coil to the cap/rotor.

www.naxja.org has a great OEM tech forum for troubleshooting exactly this type of problem.

 

[phatfoto]

While it wasn't my problem, the CPS can sometimes be good forever, and sometimes just be dead (I changed mine anyway, but the original 200,000 miler was just fine). Have you changed the distributor cap and rotor? I see you don't have spark at the plugs, but what about right off the coil?

 

[Jake Jacobson]

Thanks for the replies. We have replaced the distributor, coil, ECM. I beleive the kid checked the CPs as well, but who know's he's learning on this one. He did end up pulling the motor out last weekend and we're going to tear it down and see what if any damage was done when it overheated. Again thanks