How To Test The Fuel Pump (1991-1994 3.0L V6 Ford Ranger)

By: Abraham Torres-Arredondo
Created: 26 November 2022
Updated: 16 March 2024
Articl Id: 1438

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Using Starting Fluid

How To Test The Fuel Pump With Starting Fluid (1991, 1992, 1993, 1994 3.0L Ford Ranger And Mazda B3000)

Using starting fluid is another method to diagnose an engine no-start problem.

The starting fluid is sprayed into the throttle body and then the engine is cranked.

If the engine was not starting due to lack of fuel, it will now start and run for a few seconds.

While it's not the most accurate way to test a fuel pump, it can point your diagnostic efforts in the right direction.

I've used the starting fluid test a few times to begin my engine no-start diagnostic with good results.

IMPORTANT: The accuracy of the starting fluid test depends on all six spark plugs delivering sparks to their cylinders. If you have not checked the spark plug wires for spark (using a spark tester), do so before beginning the test. Otherwise, you may get a false positive result with this test.

These are the test steps:

1
Remove the intake air duct from the throttle body.

You don't have to completely remove it, since you'll have to reconnect it in one of the next steps.
2
Open the throttle manually, and spray starting fluid down the bore.
3
Quickly reconnect the air duct to the throttle body (you don't have to tighten the hose clamp) when you have sprayed a good squirt of starting fluid.

Reconnecting the intake air duct is a very important safety precaution in case you get a back-fire thru' the intake manifold.
4
Crank the engine once the intake air duct is back on the throttle body.
5
You'll get one of two results:

1.) The engine will start momentarily and after a few seconds will die.

2.) The engine will only crank but not start at all.

OK, let's analyze your test result:

CASE 1: The engine started and ran for a few seconds. This result confirms that the engine no-start problem is caused by a lack of fuel.

I suggest your next step is to test the fuel pump fuel pressure with a test gauge. For this test go to: Using A Fuel Pump Pressure Tester To Test the Fuel Pump.

CASE 2: The engine DID NOT start, not even briefly. This result generally tells you that a lack of fuel is NOT the reason the engine won't start.

Remember what I said about this test not being very accurate? Well, I suggest you do one more test and test the fuel pressure with a fuel pressure tester. For this test go to: Using A Fuel Pump Pressure Tester To Test the Fuel Pump.