Chrysler Repair: 1999 Concorde 3.2L Hot Soak Hard Start, fuel pressure gauge, blended fuels

Question
With ambient temps in the 40's - 50's my 3.2L exhibits hard starts after a hot soak period. Starts easily cold or after a quick stop when hot. But after sitting hot 15 minutes or so, very hard to start and runs extremely rich. Car has occasionally exhibited this over the years but the past several months this has become more frequent especially now that warmer temps have arrived. Seems to exhibit on either an E-10 gas or pure gasoline. Not throwing any error codes.

Answer
NO: 18-09-98 Rev. B
SUBJECT: No Restart/Rough Idle After A Hot Soak
DATE: Jun. 12, 1998

SYMPTOM/CONDITION:
Some vehicles may exhibit a hot engine no start, hot engine restart with a rough idle, or hot engine restart/die-out. Some vehicles may also exhibit misfire DTC’s. This condition occurs after a 10 to 20 minute hot soak and may be aggravated by alcohol blended fuels. Some vehicles may not restart until the engine cools. Fuel vapor build up in the fuel rail may be the cause for these conditions.

DIAGNOSIS:
Using the Diagnostic Scan Tool (DRB III®) with the appropriate Diagnostic Procedures Manual, verify all engine/transmission systems are functioning as designed. If Diagnostic Trouble Codes (DTC's) are present, record them on the repair order and repair as necessary before proceeding further with this bulletin. Cold soak the vehicle outdoors or in the shop for a minimum of 8 hours. Connect a fuel pressure gauge Miller Tool C4799 to the service port for the 3.2L or **3.5L** engine. On 2.7L engines, use Miller Tool C4799 plus adapter 6539. Perform fuel bleed procedures on the 2.7L and disconnect the quick connect fuel line at the rear of the engine, just below the throttle body (Figure 1). Connect the adapter 6539 to the fuel line and the pressure gauge C4799 to the adapter