Electrical issues on 2004 yukon denali/Engine cutting out

[Banjomatic]

Found someone installed a top post battery and cables had side post connectors. Adapters were cross threaded and very loose. Replaced cable ends and this cleared up several issues. But still have problem with engine cutting out or running a high idle (1200-1500 rpm)at the same time the coolant temperature gauge drops down to the lowest reading. When temperature gauge comes back up to operating temp ,the engine operates normally.

 

[Miami-Dade]

@Banjomatic Moved you here for your issues.
Welcome from Miami&NYC!

 

[Banjomatic]

Found someone installed a top post battery and cables had side post connectors. Adapters were cross threaded and very loose. Replaced cable ends and this cleared up several issues. But still have problem with engine cutting out or running a high idle (1200-1500 rpm)at the same time the coolant temperature gauge drops down to the lowest reading. When temperature gauge comes back up to operating temp ,the engine operates normally.

@Banjomatic Moved you here for your issues.
Welcome from Miami&NYC!

Thanks looking for any input to help solve the issue.

 

[Fless]

Inspect the connector at the Engine Coolant Temp (ECT) sender for good contact. You can also ohm the sender; it will show different values at various temps, but should gradually change ohms as the temp changes. A graphing scanner would help show the what the sensor is reporting over various operating temps.

If the ECT sensor mis-reports a warm engine as being cold, the computer is going to be adding fuel since it thinks it's cold.

Sudden drops in temp might mean air in the coolant system; any recent work done? Does the coolant level remain relatively steady in the surge tank? There's also the possibility of a bad thermostat. Does it get to full operating temp?

 

[Banjomatic]

Inspect the connector at the Engine Coolant Temp (ECT) sender for good contact. You can also ohm the sender; it will show different values at various temps, but should gradually change ohms as the temp changes. A graphing scanner would help show the what the sensor is reporting over various operating temps.

If the ECT sensor mis-reports a warm engine as being cold, the computer is going to be adding fuel since it thinks it's cold.

Sudden drops in temp might mean air in the coolant system; any recent work done? Does the coolant level remain relatively steady in the surge tank? There's also the possibility of a bad thermostat. Does it get to full operating temp?

Yes the engine gets to operating temperature according to gauge. I might drive 20-30 miles with no issues and then I almost feel a shudder in the vehicle and at that moment the engine coolant temperature gauge bounces randomly between normal and 160. If it drops to 160 and stays there, the engine goes into a higher rpm range, so much so that at a stop light, I will have to exert a lot of brake to get vehicle from accelerating. If I have to hold brake long enough (30 seconds or more) the engine dies and upon trying to restart only spins over without cranking. I will try starting engine several times and usually about the 4th try it cranks and resumes normal operation.