Intermittent engine floods when starting

Hi,

The first thing I would recommend checking is the fuel pressure regulator. Here is a link that explains how to test fuel pressure and the regulator:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Here are the directions specific to your vehicle. They include the manufacturer's specs.


1992 GMC Truck S15/T15 2WD P/U L4-151 2.5L
Fuel System Pressure Test
Vehicle Powertrain Management Fuel Delivery and Air Induction Fuel Pump Fuel Pressure Testing and Inspection Component Tests and General Diagnostics Fuel System Pressure Test
FUEL SYSTEM PRESSURE TEST
PROCEDURE
- Turn engine "OFF" and relieve system pressure.
- Plug THERMAC vacuum port on TBI.
- Uncouple fuel supply flexible hose in engine compartment. Install fuel pressure gauge between steel line and flexible hose.
- Tighten gauge in line to insure no leaks occur during testing.
- "START" engine and observe fuel pressure reading. It should be 62-90 kPa (9-13 psi).
- Gradually restrict (pinch) outlet side of gauge. Fuel pressure should rise to 90 to 103 kPa (13 to 15 psi). This checks maximum pressure (dead head pressure) and determines if high fuel pressure is due to a restricted fuel return line or a TBI pressure regulator problem.
- Perform Fuel Pressure Release Procedure and remove fuel pressure gauge.
- Reinstall fuel line.
- "START" engine and check for fuel leaks.
- Remove plug from vacuum port and install air cleaner assembly with new gasket.

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If that is within spec, the next suspect is the coolant temperature sensor.

If you haven't already, check to see if there are any diagnostic trouble codes stored in the computer. You don't need a scanner for this vehicle. A short jumper wire or even a paper clip will do the job. Here is a link that explains how it's done:

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Try these things and let me know the results or if you have other questions.

Take care,
Joe