Hi all. Like the title says, after replacing my crank and cam position sensors, I am still having a no start. I have fuel at the rail and pump is priming. I didn’t have my fuel pressure gauge to check psi. My jumper box died so I was unable to check for spark, but everything points to no spark.

 

Test your way to the root cause here.....testing for spark (should be strong snapping BLUE spark) and fuel pressure (49 psi is the bogey here) takes very little time and is critical in pointing you in the right direction. Without knowing the results of those two tests, it's pure guesswork. Start there.

 

will do. Jeep is currently stored 25 miles from my house so it may be up to a week before I’m able to check and report back

 

was able to test fuel pressure at rail. Pump primed to ~48psi with slow drop off. Still haven’t tested for spark

 

Engine management relay HS (often called "ECM relay" or "Main relay") → without it, no power to the computer or coils.

 

the dash and gauges still come up when I go to start. Could this still be the problem?

 

Just tested for spark with plug pulled and grounded. Looks like I have no spark. Going to troll the forums on how to troubleshoot from here. If anyone would like to chime in please do

 

Check your ASD relay

 

swapped it with fuel pump relay previously. Same result

 

There is also an ASD fuse. #19 under the hood on a 98. https://fuse-box.info/jeep/jeep-cher...ses-and-relays

 

I just went through this on my 2000 XJ Cherokee. I had no pump & spark & no codes. Ended up w/ bad ground on fender( right next to bat). I even changed out pump & cleaned tank. I went the whole power chain, fuses, relays. Then I sprayed the bolt cause it wouldn't come loose. that's when it worked w/o fail. I had already bought an ignition switch(last on the power circuit). Figured I'd put it in anyway. That's why I'm here. Got an issue with the shaft between switch & key lockset. Don't want to hijack this thread, I'll start another.

 

Spark: 12 volts from ignition switch to the ASD relay; when the key is first turned on the PCM provides a ground to the ASD relay to energize it, then the ASD relay passes 12 volts to the coil primary side. If no crank sensor signal is generated after a couple of seconds the PCM cuts the ground to the ASD relay (and fuel pump relay too) and that cuts power to the coil (and fuel pump). Key to START and once again the PCM energizes the ASD relay. Now, a critical element is the crank sensor--no signal from the crank sensor and the PCM won't trigger the coil to provide spark.

*Refresh all grounds, disassemble make em shiny and reassemble.
*Test your ignition coil. They can be tested for both primary and secondary resistances with a meter and a manual.
*What brand of cam/crank sensors did you install? No lack of inferior sensors available on the aftermarket.