crank sensor signal

I have a s52 motor with link g4x the while dargging the crank signal goes and send a 0 rpm for a while then the signal return back what could coz this to happen is it a sensor fault or something in the harness or the car goes into safe mode due to tuning ??

I'm a little unclear on your question, but if you're losing RPM during cranking I would verify that all related items retain power during cranking, that battery voltage is not getting low i.e. under 10-11 volts during cranking as a starting point, then check for triggering errors.

From there you can use the trigger scope function to take a closer look.

no I'm loosing rpm signal during boost but other wise its doing well even when i lose signal it return back again after loosing it immediately

Sounds like an intermittent wiring issue. Those are always hard to find. Good Luck!

Like David said it could be intermittent wiring. Check the easy stuff like battery terminal connections and main ground points first.

Another issue I've run into is misfires can cause triggering issues, so if this doesn't occur if you turn the boost way down, that might be what you're experiencing.

noise can do this??

if they are intermittent wiring so it will cut the signal during cruising not just during kicking down right?? my shield wire is from prowireusa and there is no tension force to the connector so what can coz a wire to be cut ?

Causes of intermittent connections: Bad crimps on the terminals, Terminals not fully seated in connector housings, wire that has been bent / crimped severely and is fractured internally.

One way to find the location of the problem is to run the car (normally idle is OK, but sometimes you need a helper to run at the RPM where the problem occurs), and wiggle the wires near the crank sensor connector and work your way back to the ECU connector. Sometimes having the laptop connected so you can be watching / logging diagnostic errors while you do this. Be careful, and hopefully you find it quickly.

thank you david i will try and going to tell you what i found