97 TJ Crank No Start No Spark
Hello all, I know this subject has been beat to death as I spent all yesterday reading posts trying to figure out my Crank No Start problem but I am slightly stumped. Here's the backstory: Jeep died while driving home from work the other day could'nt get it started and I had to get it towed home. It's had a CEL for a little while for the code Incorrect Purge Flow. So Wednesday night I finally switched out the Purge Canister solenoid thinking that would cure the problem. I swapped it out and it started right up like no problem. Thursday morning I'm driving to work and the serpentine belt started to come apart (had been meaning to change it) and I figured I could get where I needed to be and then swap it with the spare I had. Well, while the belt was shredding and spinning around it knocked the vacuum lines of that Purge Solenoid and the engine quickly sputtered and died. Now I have since replaced the serpentine belt and reconnected the vacuum lines and the Jeep just cranks and cranks. I can hear the fuel pump prime when turn the key to run. I checked and no spark at spark plug and no spark from coil to distributor cap. I checked the crank position sensor for resistance and its good. I swapped the ASD relay with both the ac and horn relay and no change. Also verified there's power at the ASD relay plugin from power distribution box. I checked and the coil seems to be getting power but i think i need to check resistance again to verify the coil is good. From what i've read i also need to check cam position sensor on the distributor? Or could i have missed a ground wire somewhere that may have gotten disconnected or something? I have seen suggestions about a bad PCM on other threads but i don't believe that to be the case, all the gauges on the dash work. Also forgot to mention the fuses all look good. Sorry for the long post, I spent all day yesterday trying to track down this issue. Any and all help is greatly appreciated!
Disconnect the plug for the ignition coil and check to see if you're getting 12v at the DG/BK wire and a constantly switching on/off ground at the GY wire while the ignition switch is held in START. No ground? Repair the GY wire from the coil to PCM. Good power and ground? Either the coil or the lead from the coil to distributor is bad. No power at the DG/BK wire? Check for continuity from the DG/BK wire at the coil plug to the ASD relay output (DG/OR) in the PDC -- if you don't have continuity on the power leg, you can further determine where the break is by checking continuity at connector C103 (grey connector just inboard of the PCM) for the DG/BK wire between C103 and the coil plug, and from C103 DG/BK wire to the ASD relay socket DG/OR wire.
2000 TJ SE
2005 LJ Rubicon
Hey thanks for the help! I checked power to the coil both with key on and while starting. That checked normal so I pulled the coil and checked for continuity. It ended up failing and I found multiple cracks on the coil itself. Bought a new one installed it and the Jeep fired right up. Definitely a relief to have it running back to normal.
|crank no start , ignition , no spark|
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