1994 Astro Base Model with No A/C Shows Diagnostic Code P66 - Hard Start and Hesitation at Acceleration
Hello, I own a 1994 Chevrolet Astro base model without air conditioning. After replacing the Engine Control Module (ECM), I've noticed that the vehicle starts difficult in the morning and hesitates when accelerating from a stop. The engine runs smoothly once the temperature gauge shows a slight rise from cold. A diagnostic code P66 is now being displayed on the dashboard. Since this vehicle was originally built without air conditioning, I'm wondering if this affects the code interpretation or whether there's another underlying issue related to the ECM replacement. Any insights into what might be causing the P66 code and the starting/hesitation problems would be greatly appreciated.
Could you please share the 8th character of your VIN? This helps determine which specific PCM version was used in your vehicle. Since it's a base model without air conditioning, confirming this detail is essential for accurate diagnostic code interpretation. Additionally, does the hard start in the morning point to a throttle body issue—specifically related to the two injectors in the throttle body? Also, how does the transmission shift under normal driving conditions?