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Q: Changed throttle body assembly, now it won't start

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I just brought 03 denali 6.0 died on way home pull over n seen battery cables were lose so tighten them it cranked further down the road it did it again wiggle wires that were lose so tighten them again it cranked.now I drove it it died again so I tap on throttle position sensor it cranked.so I replaced throttle body n now it won't start turns over ttys but nothing.check all fuses,wires,trace them down all good fuel pumps is coming on.put it on scanner no codes come up I think it ain't getting fuel so I just brought a fuel filter to see if that's it.so if you can give me something else to do I would love too no.

My car has 152789 miles.
My car has an automatic transmission.

Hi and thanks for contacting YourMechanic. The problem might be with the crankshaft position sensor being effected by heat. This can be verified by measuring the resistance of the crankshaft sensor with a digital volt ohm meter (DVOM) and then heat the sensor with a heat gun to see if the sensor resistance reading goes out of spec.

If the crankshaft sensor is reading normal, then the ignition switch may have a burned contact or has corrosion. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can pinpoint the cause of the starting problem.

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