Engine hesitates when cold

1994 FORD F-150
215,000 MILES • 5.0L • V8 • 4WD • AUTOMATIC
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GOLDFORD150
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  • 1 POST
When cold starting, the engine revs up then surges for a few minutes before returning to normal idle. If you attempt to drive it before warming up, it hesitates for 10-30 seconds and then returns to full power. Seems to run fine once warm.

When this happens, the check engine light starts flashing error codes. Codes are:

61, 72, 53, 85, 36, 63, 21, and 54 - Flashed in that order.

Cleaned the MAF, replaced plugs, wires, distributor cap, rotor.

Not sure where to start next with so many codes! Any help is greatly appreciated!
Jun 14, 2022 at 4:08 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,273 POSTS
The codes 21 and 61 are giving you for the engine coolant sensor is open or no good. here is the location so you can check the connector and replace the sensor. Here is a generic guide on how to change the coolant sensor out with instructions in the diagrams below for your truck. Clear the codes once completed.

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement

Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.
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Jun 14, 2022 at 10:43 AM
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