How To Test The Fuel Pump (1990-1997 2.3L Ford Ranger, Mustang)

TEST 2: Using Starting Fluid To Confirm A Lack Of Fuel

As mentioned earlier, the idea behind using starting fluid is to confirm that a lack of fuel is causing your 2.3L Ford Ranger (Mustang or Mazda B2300) to crank but not start.

This is usually the very first thing that most techs will do when they suspect that the fuel pump is bad (or that the no-start problem is due to a lack of fuel).

NOTE: To get an accurate test result from the starting fluid test, you need to first check and confirm that the ignition system on your 2.3L Ford Ranger (Mustang or B2300) is creating and feeding spark to all 4 cylinders. Without spark already present... the starting fluid test won't prove or disprove that a lack of fuel is the problem behind the no-start condition.

IMPORTANT: This is a very fast and easy test but you do have to take one very important safety precaution and this is to reconnect the air intake duct after spraying starting fluid down the throttle bore (although you don't have to fasten it). This will prevent any backfire, that might occur, from scaring the heck out of you when cranking the engine.

This is what you have to do:

1. 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. 2

   Open the throttle plate and spray starting fluid down the bore.
   
   As a safety precaution reconnect the air duct after you have sprayed a good squirt of starting fluid (but you don't have to tighten the air duct's hose clamp).

3. 3

   Crank the engine once the air duct is back on and you're clear of the engine compartment.

4. 4

   You'll get one of two results with this test:
   
   1.) The engine will start momentarily and after a few seconds will die or.
   
   2.) The engine will only crank but not start at all.

OK, let's find out what your results mean:

CASE 1: If the engine started and ran for a few seconds. This test result tells you that the reason your 2.3L Ford Ranger (Mustang, Mazda B2300) is cranking but NOT starting is due to a lack of fuel.

CASE 2: The engine did not start, not even momentarily. This usually means that a lack of fuel IS NOT the reason your car is not starting.

Now, remember what I said about this test not being very accurate? Well, I suggest you do one more test and this is to check the fuel pressure with a fuel pressure test gauge.