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cranks, no spark, new cps - trying to resurrect the dead

ptimhere

NAXJA Forum User
Location
new london, ohio
Ok, this is a little complicated. We have an 01 xj. Blew the motor about a year and a half ago. Late last year, we picked up a motor from a 98 cheap. We managed to get the engines swapped out before work went crazy and winter set in.

Now they we are a little less busy, my son and I are trying to get it running. Our dilemma right now is that we have no spark. We swapped in a cam drive for the distributor so it will work with the 01 harness. We used the toothpick method and set it to TDC #1. So we expect it is good. We've also tried three different cps units (all of which test good on resistance tests).

So, first question, do the O2 sensors need to be hooked up for it to start?

We have not done the exhaust yet because of the difference between the heads and we were planning to just run the exhaust for a 98 and weld in extra bungs for the o2 sensors. Its just not done yet.

Second question, we're not getting any error codes. Is there anything else we might be missing?

It appears all the grounds are connected and there are no loose wires anywhere that aren't already accounted for in other pieces of the install ( previously mentioned o2 sensors and ignition capacitor are the only ones I see).

Any help at all is appreciated.
 
The most common mistake is to get the cam gear 180* out of phase(there are 2 TDC's for cyl #1).
 
I would love for it to be that easy at some point. At the moment, we don't seem to be getting any spark at all. If we pull the coil rail and try to ground a plug when we turn it over, there is no spark there that I can see or hear.
 
I had a 95 XJ 4.0 with a no spark condition recently. Was a faulty cam sensor. Just went dead like a light switch. You have checked 3 cam sensors and you know for sure your 4.0 is timed correctly. The only other thing i can think of that will give you no spark at all is a faulty crank position sensor.
 
Is the sensor OEM Jeep, or aftermarket? As one of our members is fond of pointing out, non-OEM sensors can be a bit of a crapshoot, sometimes they're no good right out of the box.
 
Also, the 00-01 CkPS has a different PN than the 96-99. Could be a lot of things. I am taking this that the engine is cranking over. I have an aftermarket that works. Will replace with MOPAR though.

Fuel, air, spark. So, volts at battery? Volts to PDS? I forgetting the name of the fuse in the PDC. Volts to #10 or #11 in the fuse panel passenger foot well. Check fuel pressure? Check volts to fuel pump? Use NOID light to check Injectors?

Mine issue end up being the electronic ignition switch. I could not find a procedure to test it. So, I replaced it.

The TPS could be a culprit. Talked to a neighbor who services Jeeps etc. Sometimes they do not throw a code. Is your Airbag waring on? For some reason, I was told they TPS and the Airbag clock spring uses the same voltage line. ???

ECM bad ?
 
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