I have a 1997 Buick Park Ave and every summer i have a problem when the engine temperature reaches 205 F to 212 F.
The car hesitates on acceleration and stalls but will start right up. It will continue to do this as long as the engine temperature
is in the above range. If i slowly feed the gas it will be fine. It never does it in the winter time when the engine temperature is below
205 F. I have had it to several mechanics and changed many parts including crank and camshaft sensors, Ignition control module and coils and MAS and air and fuel filters.
My engine is the 3800 series II V6
Any help would be greatly appreciated since I am at wits end.

Welcome to the forum.
This may help! See this thread: https://www.gmforum.com/normal-maint...2/#post1597076
Also has anyone checked the fuel psi readings ?

Yes fuel psi has been checked and they said it was ok

Has the throttle body & IAC ever been cleaned?

yes they have been cleaned and air filter changed.

Like I said earlier my problem only occurs in the warm weather and not in the winter.

I'd love to know the actual readings they got. We often hear that it was okay but then later get the number and find it is marginal or not okay.

If would be good to know fuel pressure in the following configurations:

- Key on engine stopped
- Engine idling
- Engine idling, vacuum line disconnected from fuel pressure regulator and vacuum line temporarily plugged

How many miles on the car?

How many miles have you owned it?

How many miles on the spark plugs?

How many miles on the spark plug wires?

I would have to get a fuel gauge from Autozone and test it myself.

1. Car has 90,000 miles
2. I have owned it the last 60,000 miles
3. spark plugs and wires changed 25,000 miles ago and wires still look good and no arcing.