96 Mustang GT Dying in Traffic
About a month ago, my mustang died in traffic after spending quite a while crawling along. At first, I thought it was the alternator or poor electrical connection, as a jump from my buddy brought it back to life, and later on after detaching and reattaching the terminals it was running fine. Gave it no more thought.
Well, that didn't fix the problem! Last week I died in traffic on the interstate on the way down to tail of the dragon in NC. We thought it might be fuel, so we replaced the fuel filter (it was completely disgusting in there, definitely needed to be done!) and it started up again. 5 miles down the road I broke down again....still in traffic. After 20 minutes or so of waiting, I got it going again and it ran well as long as I was moving.
When the issue is about to occur, I can tell as the throttle can be depressed 10-15% and it feels like it bogs, before moving to e.g. 20% and it will jump as if i stabbed it straight from 0 to 20%. As long as I am driving, the car will not die, but as soon as I go to idle it will start to dip from usual 650-750 to 400 and back again a few times before just dying. It is hard to start after this - it will crank a lot, giving it a lot of gas can sometimes get it to start but usually it just turns over a couple times and makes a few popping sounds before dying. If I wait 15 minutes it will start up and run fine.
Any advice? Only CEL is P1443 (intermittent, ordered new solenoid valve), recently had the DPFE/EGR code (P0402 excessive egr?) and replaced those components, as well as spark plugs. I got 23.5 mpg on the drive home going relatively quickly on the highway, so I don't think the car is having an issue while it's moving properly.
Troubleshooting steps/recent maintenance so far:
Ordered IAC & charcoal solenoid valve
Replace fuel filter
Replace EGR Valve
Replace Spark Plugs
Replace Coil Pack
Clean MAF & air temp sensor
Inspect Throttle Body (clean)
Verify electric fan turns on and off (it does!)
Replace PCV valve
Monitor temps with OBDII reader (died at 206~208, was doing fine driving aggressively at low speeds at 210-212. A few times during this monitoring the sensors would go whacky e.g. -4 F coolant readout - obviously wrong, throttle position would go 10-15-20-75-80-85-30-35... as I gradually pressed the pedal, reflected in the car bogging a little during those occasions)