As you're probably already aware, the fuel system on 1993-1996 2.2L Buick Century and 2.2L Oldsmobile Cutlass Ciera does not come with a Schrader valve.
No Schrader valve, no problem! The fuel pump can still be tested with a fuel pressure test gauge and in this tutorial I'll explain how step by step.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar La Bomba De Combustible (1993-1996 2.2L Buick Century, Oldsmobile Cutlass Ciera) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 2.2L Buick Century: 1993, 1994, 1995, 1996.
- 2.2L Oldsmobile Cutlass Ciera: 1993, 1994, 1995.
- 2.2L Oldsmobile Ciera: 1996.
Symptoms Of A Bad Fuel Pump
A fuel pump failure will usually cause one of two types of problems:
- The engine does not start
- The engine starts and runs, but runs very badly.
If the fuel pump still functions, but doesn't send the correct amount of fuel, you'll see one or more of the following symptoms:
- Engine takes longer than usual to start (extended cranking).
- Engine idle is very rough.
- Engine backfires thru' the intake manifold under load.
- Engine starts, then dies.
Both can be diagnosed with a simple fuel pump pressure test.
Where To Buy A Fuel Pressure Test Gauge
The following fuel pressure test kit has the quick disconnect adapter you need to test the fuel pump's performance.
I'm also including a link to the quick disconnect tools you'll need to disconnect the fuel line to connect the fuel pressure tester's quick disconnect adapter.
Using A Fuel Pump Pressure Tester To Test The Fuel Pump
To connect a fuel pressure test gauge to the fuel system, you'll need to use a 3/8" quick disconnect fuel pressure test adapter (see photo 2 of 3 above).
This adapter has to be installed between the fuel rail and the 3/8" fuel feed line (that comes from the fuel filter). The orange arrow in photo 1 of 3 above points to this fuel line.
To disconnect the fuel line, you'll need a quick disconnect fuel line tool (see photo 3 of 3 above).
NOTE: If you don't have a fuel pressure tester with the correct adapter or don't have the quick disconnect tool, take a look at this section: Where To Buy A Fuel Pressure Test Gauge.
The fuel pump pressure specification for the 1993-1996 2.2L Buick Century and Oldsmobile Cutlass Ciera is:
- 40-47 PSI Key On With Engine Off.
- With Key On Engine Running, fuel pressure should drop 3 to 10 PSI.
OK, these are the test steps:
Place a shop towel around the fuel pressure line (where it connects to the fuel injector rail). The shop towel's job is to absorb any fuel that may leak when doing step 2.
Disconnect the fuel pressure line from the fuel injector rail.
NOTE: You'll need to use a quick-disconnect tool to disconnect the fuel pressure line from the fuel injector rail.
Connect the test adapter between the fuel pressure line and the fuel injector rail.
Connect the fuel pressure gauge to the adapter.
When ready, ask your helper to cycle the key ON and OFF but don't crank the engine.
Check your connections for fuel leaks. Resolve any fuel leaks before continuing to the next step.
Crank the engine and check the fuel pressure gauge.
Your fuel pressure gauge should register the specified fuel pressure.
Let's interpret your test results:
CASE 1: The fuel pressure test gauge registered 0 PSI. This test result confirms the fuel pump is not sending fuel to the fuel injectors.
This test result usually confirms the fuel pump has failed and needs replacement.
CASE 2: The fuel pressure gauge registered the indicated fuel pressure specification. This is the correct and expected test result and it tells you the fuel pump is functioning correctly.
If your vehicle is not starting, you can conclude that the fuel pump IS NOT the cause.
CASE 3: The fuel pressure gauge registered a fuel pressure way below the specification. This test result tells you that the fuel pump is failing.
Replace the fuel pump, fuel pump strainer, and the fuel filter.