Engine died and couple other weird things

[ALScott]

Yesterday we drove around for a while in neighborhoods just enjoying the weather. I made a left, full lock u-turn going really slow and the engine died. AC was on too. It fired right up but still weird. Parked for about 3 hours and then made some quick trips and a couple of times when shifting into drive it shuddered like it was going to die but went into gear no problem and we drove off. Is any of this a sign of anything? I have always thought it seemed like it's idling low but I don't know where it should idle. That tach makes no sense to me. It is currently idling at or just below the last dot under 1k on the tach.

 

[ALScott]

No opinions on this one?

 

[AjRagno]

Try cleaning the IAC. Do do so, get the engine up to operating temp then turn it off and remove the air intake tube from the throttle body. Now start the engine and slowly spray at least 1/2 can of throttle body cleaner into the IAC port in the throttle body.

The engine will choke and may die but that’s fine.

 

[CharlesHS]

Take a look at the electrical harness that goes behind the valve cover and around the threaded head stud on the right side. This is a known problem where the threads wear thru the harness insulation and short the wiring to ground. These wires are the communications between the ECU, the fuel injectors, TPS, CKPS, CMPS, IAC, MAP and other sensors. Verify the wiring insulation does not have copper strands showing thru.
Look at the four 32 pin harness connectors at the ECU; check the pins for oxidation and make sure the connectors are firmly snapped into the ECU receptacles.
Also could hurt to look at the CMPS connector at the back of the intake manifold along with the harness wiring going to the sensor.