Hi and thanks for using 2CarPros.com.
Wow, you have done a lot. If spraying starting fluid along the intake didn't make much of a change, I doubt the problem is related to the intake gasket.
Interestingly, when you disconnected the MAP sensor vacuum, it ran better for a short time. Since disconnecting it would have allowed more air into the system, I question if there is an issue with fuel pressure (too high) causing the problem.
You did not mention checking it, so start there. Here are general directions for checking both pump pressure and the pressure regulator:
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator
Here are the directions specific to your vehicle along with the manufacturer's specifications:
FUEL SYSTEM PRESSURE TEST
PROCEDURE
A fuel system pressure test is part of several of the Diagnostic Charts and Symptom Checks. To perform this test, follow this procedure:
Note: To perform residual pressure check refer to: Fuel Pump, Testing and Inspection.
1. Turn engine OFF to relieve system pressure.
- Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine.
- Loosen fuel filler cap to relieve tank vapor pressure.
- The constant bleed feature relieves fuel pump system pressure when the engine is turned "OFF".
2. Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose.
3. Tighten gauge in line to insure no leaks occur during testing.
4. Connect negative battery terminal and START engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi). If not, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6).
5. Turn engine OFF to relieve system pressure.
- Disconnect negative battery terminal to avoid possible fuel discharge if an accidental attempt is made to start the engine.
- Loosen fuel filler cap to relieve tank vapor pressure.
6. Remove fuel pressure gauge.
7. Install new O-ring on fuel feed line. Reinstall fuel line.
8. Connect negative battery terminal and START engine and check for fuel leaks.
9. Install air cleaner assembly.
Let me know what you find or if this is something you have already done.
Take care,
Joe
SPONSORED LINKS
Wednesday, July 25th, 2018 AT 9:44 PM