2001 Mustang GT Engine Spitting

Hi,
-Pull your COP’s, shine a light down and look for moisture, this is very common...Resistance testing across the COP’s as follows.On our COPs the two terminals where the harness connects to each are the Primary windings. They should read between 0.3 to 0.8 Ohms. Between the coil output (Secondary) and either of the primary pins you should get 4k to 10k Ohms. If one’s zero, it’s open and needs replacing.
-Look at all your COP Connectors, if the retaining clip is gone, they can back off the pins. Tie wrap around it to hold the connector on tight, for now- replace faulty connector(s).
- The same goes for Fuel Injectors, verify the connections are good and held on tightly.
- Pull your Plugs and verify the electrodes are light Tan to Black in Color. If worn, replace. Otherwise, clean- Regap- Never seize on Threads- Reinstall.
-Pull your Cool Air or Stock intake apart and clean the MAF, Throttle Butterflies, IAT and Intake internally, with CRC MAF Sensor cleaner.
- Check all your
- Check around and verify there’s no Vacuum ines that are poorly connected, or dryrotted. Replace as necessary.
- Have you Had any CEL’s show up? If you have a Scantool- great! If not, Borrow, or Advanced Auto will have one to look at real-time Data & that does a drive cycle Datalog. Seek out PENDING Codes. View Data in the recorded Drive when stumble occurs in the Cycle, look for a Sensor, I.e. 02 Sensors, etc.. pegging in one direction, not correcting back & forth as designed. Watch at Idle as well, live.

Apologies- Sent too early, new Puppy. Need I say more? Lol!
- Check all your Fuel System components. Change your Filter. Check your Fuel Pressure. You should have a pressure Gauge on the rail. Check Wiring of the Fuel System for Damage, loose Connections.
- It May be an 02 , Crank Trigger, ECT Sensor, CPS. They will usually- not always, throw a Code. It takes a while, sometimes. All the very simple things should be ruled out first. If your COP’s or other Ignition components are Aftermarket, they are usually good suspects.
-Do your COP measurements on Components when Cold, warm with a Hair Dryer and retest.
Thermal expansion/contraction causing intermittent issues are common.
- Check all your Fluids. Replace Oil & Filter if timeframe necessitates.
- Check your Charting System: Alternator Output Voltage, Connections, Grounds, Battery Voltage.
Hopefully you will have results, if not- know what’s ruled out & where to go, next.
If you don’t already, Catch Cans for the PCV System are good to have, especially with a Supercharger. This catches the pressurized Oil (from BlowBy) prior to it entering and crudding up things, being piped into the intakes air stream.
Good Gauges to monitor Forced Induction:
- A WideBand 02 Fuel/Air Ratio Gauge
- A Coolant Temperature Gauge.
- A Fuel Pressure Gauge
Mounting them in a Pillar style fashion keeps them within eyeshot, out of the way.
Good luck!

If this were my car I would be monitoring some key PID's with an ODB2 scanner to see if their values are "reasonable".

• IAT
• ECT
• MAF flow
• Fuel rail pressure sensor (FRPS). Double check that the intake vacuum reference line is connected and leak free.
• timing advance
• Long term fuel trim (LTFT) for bank 1 and 3.

Here's some information on a DIY'er ODB2 full function scanner.

ForScan ODB2 scanner w ELM327 USB
https://www.stangnet.com/mustang-forums/resources/forscan-odb2-scanner-w-elm327-usb.57/

Also not a bad idea to do a full review of the battery and charging system.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/