Re: 2000 5.0L Gi Throttle Hesitation
There are a lot of things in the fuel and electrical system that can cause your problem. Without the OEM EFI Diagnostic manual, a way of reading codes, sensor voltages and outputs. I really don't know how you can troubleshoot it. But here is some information on the basic things to check. there are whole sections of the manual that covers details on checking each item. Way beyond the scope of this board.
Before Using This Section......................................
Before using this section you should have referred to the On-
Board Diagnostic (OBD) System Check and determined that:
Step 1. The ECM is operating correctly
Step 2. There are no DTC’s stored
Symptom.......................................................................
Verify the customer complaint, and locate the correct symptom in the
table of contents. Check the items indicated under that symptom.
Visual / Physical Checks.................................................
Several of the symptom procedures call for a careful visual physical
check. The importance of this step cannot be stressed too strongly.
It can lead to correcting a problem without further checks, saving
valuable time.These checks should include:
• ECM grounds and sensors for being clean, tight and in
their proper locations.
• Vacuum hoses for splits, kinks, and proper connections.
Check thoroughly for any type of leak or restriction.
• Air leaks at throttle body mounting area and intake manifold
sealing surfaces.
• Ignition wires for cracking, hardness, proper routing and
carbon tracking.
• Wiring for proper connections, pinches, and cuts. If wiring
harness or connector repair is necessary, refer to General
Information section or On-Board Service section
for correct procedure.
• Moisture in primary or secondary ignition circuit connections.
• Salt corrosion on electrical connections and exposed
throttle body linkages.
Fuel System Checks ..............................................
• For water contaminated fuel, and dirty or restricted fuel
filter
• Fuel pressure. Refer to Chart A-4 or A-5 in Diagnoses
section.
• Worn throttle linkage
• Check Fuel Injectors.
Ignition System Checks...........................
• IC system for proper timing and advance
• Spark plug wires for being faulty
• For RPM reduction mode
• Spark plugs for being fouled or improper gap
• Integrity of primary and secondary wiring, IC module,
pickup coil, and distributor.
Sensor Checks.......................................................
• TP sensor - For binding, sticking, or salt corrosion. TP
sensor voltage should increase as throttle is moved toward
Wide Open Throttle (WOT).
• TP sensor - 5 volt reference for open circuit from TP sensor
connector terminal “A” to J2-19. DTC 22 may be set.
• TP sensor circuit for open or grounds from TP sensor connector
terminal “B” to J2-26. DTC 21 may be set.
• MAP output voltage check, Chart A-8, Diagnoses section.
• ECT for shifted value.
Additional Checks ........................
• Proper alternator output voltage
• For faulty or incorrect thermostat
• Throttle linkage for sticking, binding, or wear
• Intake valves for deposits.
