cps question??? help

where exactly is the cam position sensor on an 88 xj with the 4.0 and the aw4? it cranks but it wont start. fuel is good, no spark. there is no power getting to the distributor at the harness plug. all of this worked fine before i put this motor in. i had the coil checked and it was good. any input would be great, i am about to lite this jeep on fire!!!

The big yellow wire at the coil is the power (from the ignition switch and through a few connectors), should be there when the key is in the run position. If there is no power, it´s something upstream and not sensor related.
The small yellow wire is the trigger (pulse), it is controlled by the ECU, with sensor imputs.

when the key is on there is power to the big yellow wire at the coil. but nowhere else. should the power pulse in the small yellow wire when someone is cranking the engine over? because it doesn't.

I'm going to ask a dumb question - but it's valid, because I've done it myself...

"Did you put the crank position sensor in?"

This is important, because it generates the crankshaft timing signal used to generate fuel injection and ignition event timing. If it IS in, make sure it's plugged in. If that's all good, check resistance across the sensor - you're looking for 200 ohms +/- 10%.

The Camshaft position sensor is located inside the distributor, underneath the rotor base plate. Removal of the distributor is required to replace the sensor, but I've not heard of one going bad in the last few years...

5-90

here is the problem with the crankshaft position sensor. when i pulled the old motor out, i forgot to unhook it from the harness. it pulled the plug off the end of the sensor. i cleaned the end of the two wires and spliced them back together. i rechecked the splices and they are good. it could have pulled one of the wires out of the sensor inside of the insulation where you can't see. if that sensor is bad would that cause the no spark problem? that is the only thing i have any doubt about in the whole motor install. everything else went together with out a problem.i appreciate your time with this.

Yep - bad crank sensor = no fuel/no fire. Check with ohmmeter to be sure...

You may have to go farther into the "cable" to see where the break is, or just replace the damn thing outright...

5-90

I ordered a new one today, it will be here day after tomorrow. i'll let you know if that works.

well it was the crankshaft position sensor. when i pulled the old one out, the wire was almost broken off at the sensor. the insulation was brittle and broke easily. i put the new one in and she fired right up! thanks soo much for your help. i noticed we live fairly close to each other. ever go to hollister? let me know, i go about three times a month. thanks again, chris.