Cam sync issues
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Teching In
Joined: Apr 2018
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Cam sync issues Hey everyone. I dont normally post but ive run into a brick wall. Also keep in mind that ive had this at 3 tuners and they havent been able to figure it out or finish the tune completely. I’m running a 408 with LS3 heads, 24x reluctor, rear cam sensor, and an M122 supercharger. The car is on a Holley Terminator X Max. Ever since finishing the build, I’ve had an issue where the car runs fine cold, but once it warms up and I get into it hard, it starts bucking, stalls, and won’t restart until it cools down (usually close to an hour). When it does restart, it runs fine again until the next time it’s hot and under load. I’ve already replaced the O2s, injectors, coils, plugs, and even the cam sensor multiple times (NGK brand). I also rewired the cam and crank sensors with shielded wire, routed them away from other harnesses, grounded the car thoroughly (battery to chassis, block to chassis, heads to chassis), and confirmed all power/grounds to the ECU. The issue still persists. On the Holley Terminator, after a stall, LED #6 goes green and LED #7 red. At this point I’m suspecting a cam/crank sync problem when the sensors are hot, since I’ve read Holley is very picky about using genuine AC Delco sensors. Before I throw more parts at it, I’m looking for input from anyone who’s run into similar hot-stall / no-restart issues on a Terminator X. Does this sound like classic sensor dropout, or should I be looking deeper into ECU power/grounding or coil power noise? Any input would be greatly appreciated
Arguably the best Holley tuner in the nation, @Project GatTagO is your guy to tune this. His name is Andrew. I’m moving this to tuning sub forum.
Hey everyone. I dont normally post but ive run into a brick wall. Also keep in mind that ive had this at 3 tuners and they havent been able to figure it out or finish the tune completely. I’m running a 408 with LS3 heads, 24x reluctor, rear cam sensor, and an M122 supercharger. The car is on a Holley Terminator X Max. Ever since finishing the build, I’ve had an issue where the car runs fine cold, but once it warms up and I get into it hard, it starts bucking, stalls, and won’t restart until it cools down (usually close to an hour). When it does restart, it runs fine again until the next time it’s hot and under load. I’ve already replaced the O2s, injectors, coils, plugs, and even the cam sensor multiple times (NGK brand). I also rewired the cam and crank sensors with shielded wire, routed them away from other harnesses, grounded the car thoroughly (battery to chassis, block to chassis, heads to chassis), and confirmed all power/grounds to the ECU. The issue still persists. On the Holley Terminator, after a stall, LED #6 goes green and LED #7 red. At this point I’m suspecting a cam/crank sync problem when the sensors are hot, since I’ve read Holley is very picky about using genuine AC Delco sensors. Before I throw more parts at it, I’m looking for input from anyone who’s run into similar hot-stall / no-restart issues on a Terminator X. Does this sound like classic sensor dropout, or should I be looking deeper into ECU power/grounding or coil power noise? Any input would be greatly appreciated
The first thing I would do is replace the cam sensor with a NTK brand sensor.
Andrew
Does the OP know what thrust clearance he has? Verified crank sensor is OK? The only time I ever experienced something like this was when a P0336 crank sensor code was set. Only happened when the coolant reached 186°, or more. Up to that point, it was perfect. Just sayin'....
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Joined: Jul 2025
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From: United States
Classic hot cam/crank sensor failure. Holley is extremely picky. The LED codes point directly to a sync loss.
You've done great wiring and grounding. The final step is swapping to genuine AC Delco sensors, not NGK. The cheap aftermarket sensors can't handle the heat. This is a very common fix for the exact hot-stall issue you're describing.
Also, check that your sensor gaps are set correctly to 0.050.
You've done great wiring and grounding. The final step is swapping to genuine AC Delco sensors, not NGK. The cheap aftermarket sensors can't handle the heat. This is a very common fix for the exact hot-stall issue you're describing.
Also, check that your sensor gaps are set correctly to 0.050.
