1999 My Astro starts fine and idles fine; however from around 20 to 30 mph it hesitates. after 30-40 km/hr runs good

You can try a drive cycle, see if it helps? There may be an idle relearn, if just idle issue? Usually it will relearn idle on its own by driving.
Drive Cycle Recommendations:

1. Most OBDII monitors will complete more readily using a "steady foot" driving style during cruise or acceleration modes. Operating the throttle in a "smooth" fashion will minimize the time required for monitor completion.
2. Fuel tank level should be between 1/2 and 3/4 fill with 3/4 fill being the most desirable.
3. The Evaporative Monitor can only operate during the first 30 minutes of engine operation. When executing the procedure for this monitor, stay in part throttle mode and drive in a smooth fashion to minimize "fuel slosh".

WARNING
STRICT OBSERVANCE OF POSTED SPEED LIMITS AND ATTENTION TO DRIVING CONDITIONS ARE MANDATORY WHEN PROCEEDING THROUGH THE FOLLOWING DRIVE CYCLES.
For best results, follow each of the following steps as accurately as possible:
OBDII Monitor
Exercised Drive Cycle Procedure
Purpose of
Drive Cycle Procedure Drive Cycle
Preparation 1. Install scan tool. Turn key on with the engine off. Cycle key off, then on. Select appropriate Vehicle & Engine qualifier. Clear all DTC's/ Perform a PCM Reset. Bypasses engine soak timer. Resets OBDII Monitor status. 2. Begin to monitor the following PIDs: ECT, EVAPDC, FLI (if available) and TP MODE.
Start vehicle WITHOUT returning to Key Off. 3. Idle vehicle for 15 seconds. Drive at 64 Km/h (40 MPH) until ECT is at least 76.7°C (170° F). Prep for Monitor Entry 4. Is IAT within 4.4 to 37.8°C (40 to 100° F)? If Not, complete the following steps but, note that step 14 will be required to "bypass " the Evap monitor and clear the P1000. Engine warm-up and provide IAT input to the PCM. HEGO 5. Cruise at 64 Km/h (40 MPH) for up to 4 minutes. Executes the HEGO monitor. EVAP 6. Cruise at 72 to 104 Km/h (45 to 65 MPH) for 10 minutes (avoid sharp turns and hills) Note, to initiate the monitor: TP MODE should =PT, EVAPDC must be >75%, and FLI must be between 15 and 85% Executes the EVAP Monitor (If IAT is within 4.4 to 37.8° (40 to 100°F)) Catalyst 7. Drive in stop and go traffic conditions. Include five different constant cruise speeds, ranging from 40 to 72 Km/h (25 to 45 MPH) over a 10 minute period. Executes the Catalyst Monitor. EGR 8. From a stop, accelerate to 72 Km/h (45 MPH) at 1/2 to 3/4 throttle. Repeat 3 times. Executes the EGR Monitor. SEC AIR/CCM (Engine) 9. Bring the vehicle to a stop. Idle with transmission in drive (neutral for M/T) for 2 minutes. Executes the ISC portion of the CCM. CCM (Trans) 10. For M/T, accelerate from 0 to 80 Km/h (o to 50 MPH), continue to step 11. For A/T, from a stop and in overdrive, moderately accelerate to 80 Km/h (50 MPH) and cruise for at least 15 seconds. Stop vehicle and repeat without overdrive to 64 Km/h (40 MPH) cruising for at least 30 seconds. While at 64 Km/h (40 MPH) , activate overdrive and accelerate to 80 Km/h (50 MPH) and cruise for at least 15 seconds. Stop for at least 20 seconds and repeat step 10 five times. Executes the transmission portion of the CCM. Misfire & Fuel Monitors 11. From a stop, accelerate to 104 Km/h (65 MPH). Decelerate at closed throttle until 64 Km/h (40 MPH) (no brakes). Repeat this 3 times. Allows learning for the misfire monitor. Readiness Check 12. Access the ON-Board System Readiness (OBDII monitor status) function on the scan tool. Determine whether all non-continuous monitors have completed. If not, go to step 13. Determines if any monitor has not completed. Pending Code Check and Evap Monitor "Bypass" Check 13. With the scan tool, check for pending codes. Conduct normal repair procedures for any pending code concern. Otherwise, rerun any incomplete monitor.
Note: if the EVAP monitor is not complete AND IAT was out of the 4.4 to 37.8° C (40 to 100° F) temperature range in step #4, or the altitude is over 2438 m. (8000 ft.), the Evap "bypass" procedure must be followed.Proceed to step 14. Determines if a pending code is preventing the clearing of P1000. Evap Monitor "Bypass" 14. Park vehicle for a minimum of 8 hours. Repeat steps 2 through 12. DO NOT REPEAT STEP 1. Allow the "bypass" counter to increment to two.
© Ford Motor Company

have you balanced and rotated your tire.

With the car running take a can of starting fluid and spray around the intake. those cars are known for bad intake gasket leaks. if the engine idles up on its own when you spray it. you have a bad intake. make sure to check and spray vac lines as well.

Check for stuck open EGR valve or a bad MAP sensor.

sounds like a spark plug is fouling out,or a clogged fuel filter.

WELL YOU CHANGED ALMOST EVERY THING EXCEPT IGNITION CONTROL MODULE........

P1000 means a drive cycle has not completed, it will only clear itself after driving the vehicle through certain driving conditions. If you try to clear the code, it will reappear until you repeat the drive cycle. I am not too familiar with what AE will show, but if you can access Mode 6 data or the OBD Drive Cycle(These are two options from the IDS at Ford), It may help to show what tests have either failed or not completed. Heres what must be done to clear the P1000:


Note: The IAT PID must be between 10-38°C (50-100° F) during the OBD II drive cycle to enter into all the OBD II monitors. The FLI PID must be between 15% and 85% at all times.

Drive in stop-and-go traffic with at lease 4 idle periods (30 seconds each) while observing the status of the OBD II monitor on the scan tool. If the exhaust gas recirculation (EGR), heated oxygen sensor (HO2S), evaporative emission (EVAP), secondary air (AIR) (if applicable) or catalyst efficiency monitor have not completed, drive on the highway at a constant speed over 64 km/hr (40 mph) not to exceed 104 km/hr (65 mph) for up to 15 minutes. Heavy accelerations, sudden decelerations and wide open throttles are not recommended. If the scan tool sends out a three pulse beep at any time, the OBD II drive cycle has completed.

If there is only one certain component that hasn't completed its test, there are individual driving conditions to help those tests pass or fail if something is wrong.

your ECU is faulty.
New ECU and voila problem fixed

ohh ECU= engine control unit

secondhand with do just fine.

get it fitted by professional

It is perfectly normal for the idle speed to increase with the AC on. This is done to ensure that adequate coolant flow is available for the increased strain the compressor puts on the engine.

If the idle increase is too high, there is a safety problem. There is an idle adjustment that can be made to reduce RPM to factory specification when the AC is on.

It sounds like u need to change the fuel pressure regulator. U can pick one up for around 40$. Its not all that hard to change yourself.