I have this issue where the car dies if the engine is warm and it's idling in gear. It won't die in park or when cool, and it slowly dies from running lean I assume. I do have a stored code 22 which is low voltage to TPS, but when I checked the voltage it showed .65v at closed idle. I have replaced the TPS, IAC, and the connectors for both of those. I haven't tested the ground yet and I'm not sure how to go about that to be honest. Any help is appreciated thank you.

 

https://www.thirdgen.org/tpimod2

Did you do this...??? Pay particular attention to the smooth sweeping increase in volts while opening throttle... The target rpms may actually apply to TPI so break out that FSM well that's if you have one.

 

The Usual Four:

1. Verify System Voltage. Most “12-volt” batteries should show 12.6—12.8 when fully charged, depending on battery construction and temperature. A “12-volt” battery measuring 12 volts on an accurate voltmeter is near-dead. Assure battery connections are clean and tight. Battery voltage during cranking should never go below 9.5 volts, and then only when the battery is very cold (below freezing.) Higher voltage during cranking is better. Running voltage--alternator charging--is generally 14.x volts measured at the alternator output terminal.
   
2. Verify fuel pressure at prime, at idle, and under load. Most fuel pressure gauge assemblies have a push-button pressure release connected to crappy vinyl tubing. Route the tubing so it empties into a drain pan, then push the button while the engine is running. This simulates higher fuel demand if you can't check fuel pressure on the highway. Fuel pressure should remain steady even with fuel flowing down the pressure-relief tubing. TBI systems don't hold pressure when the pump stops running, but the other fuel injection styles should. How old is the fuel filter? Have you ever dumped a bottle of Chevron Techron Complete Fuel System Cleaner into the gas tank? (Recommended at every oil change.) Use Top Tier fuel which has additional detergents beyond what the EPA mandates, to keep the injectors clean. Remember, a "weak" fuel pump can be a defective pump...or low voltage to the pump, or a poor fuel pump ground, or a plugging fuel filter including the filter sock on the bottom of the pump.
   
3. How old are the usual “tune-up” parts and procedures? Inspect/replace distributor cap, rotor, plug wires, spark plugs. Use quality parts sourced from an authorized seller (NO COUNTERFEIT PARTS FROM AMAZON, EBAY, OR OTHER SKETCHY SELLERS!) Be sure the ignition coil will reliably fire a spark-tester calibrated for HEI when the coil is fully warm, and misted with water from a squirt-bottle. Cranking compression test of all cylinders while the spark plugs are removed. Verify EGR, PCV, EVAP, and Heated Air Intake (if used) systems for proper operation. Verify proper initial timing and electronic spark advance. Replace old O2 sensors unless you can PROVE that they're working properly—old O2 sensors get lazy, they don't provide accurate data, but they do provide “data” that fools people into thinking they're “working”. The catalyst output temperature should be HIGHER than the inlet temperature once the engine is at full operating temperature.
   
4. Connect a scan tool (NOT a crappy “code reader”) and look for “codes”. More important, look at the data stream to verify EVERY sensor and computer output. Verify fuel trims during the time that the vehicle is not running properly. “Codes” have official diagnostic procedures that will be found in the service manual set for your vehicle.