The fuel pump pressure can be easily tested to diagnose a good or bad fuel pump on the 1991-1996 1.9L Ford Escort or Mercury Tracer.
What makes checking the fuel pump pressure so easy is the fact that the fuel injector rail has a fuel pressure test port, Schrader valve, where we can connect our fuel pressure test gauge to.
In this tutorial, I'll explain how to do the fuel pump pressure test to see if the fuel pump is behind an engine no-start problem or an engine performance problem.
I'm also going to show you how you can do a starting fluid test to see if an engine no-start problem is due to a fuel delivery problem.
Contents of this tutorial:
APPLIES TO: This tutorial applies to the following vehicles:
- 1.9L Ford Escort: 1991, 1992, 1993, 1994, 1995, 1996.
- 1.9L Mercury Tracer: 1991, 1992, 1993, 1994, 1995, 1996.
IMPORTANT: Gasoline is highly flammable! Take all necessary safety precautions, be alert, be careful. Starting fluid and gasoline can ignite very easily.
Symptoms Of A Bad Fuel Pump
Your Ford Escort or Mercury Tracer's fuel pumps will usually let you down in one of two ways:
- Total failure: The pump quits completely, fuel pressure drops to zero, and the engine simply won't start.
- Weak pump: The pump is still running but can't keep up with demand. It's delivering just enough fuel to get the engine started, but not enough to keep it running the way it should.
When you're dealing with a weak pump that can't keep up, you'll usually be spotting one or more of these telltale performance problems:
- The engine takes a long time to start.
- The engine may start but will stall soon after.
- Lean air/fuel mixture diagnostic trouble codes illuminate the check engine light.
- The engine stalls as soon as you accelerate the engine under load.
- Backfire through the intake manifold when accelerating the engine under load.
- Lack of power when accelerating the engine under load.
Where To Buy A Fuel Pressure Gauge
When it comes to checking an engine no-start or an engine performance problem, a pressure gauge is one of the handiest tools you can own.
The good news is they're not expensive (like in the old days). Most auto parts stores carry them, and if you're looking to save a few bucks, you can find one online for even less. These are the ones I recommend:
Disclosure: As an Amazon Associate, I earn from qualifying purchases. Buying through these links helps support this site at no extra cost to you. Thanks for your support —it really means a lot!
Fuel Pressure Specifications
The fuel pressure specifications on the 1991-1996 1.9L Ford Escort or Mercury Tracer are:
| Year | KOEO | KOER |
|---|---|---|
| 1991-1993 | 35-45 PSI | 30-40 PSI |
| 1994-1995 | 35-45 PSI | 28-33 PSI |
| 1996-1998 | 38-46 PSI | 31-38 PSI |
- KOEO: Key On Engine OFF.
- KOER: Key On Engine Running.
TEST 1: Fuel Pressure Test With Gauge
Like I mentioned at the start of this tutorial, testing the fuel pump is a breeze because a fuel pressure test port (Schrader valve) is installed on the fuel rail. (see image 2 of 2 above).
This Schrader valve looks just like the one used on a bicycle tire, where you hook up the air pump to inflate the tire.
Before you begin the test, I want to point out that you should first make sure the fuel pump inertia switch hasn't tripped. If it has, the fuel pump won't get any power, and your fuel pressure test will only give you a 0 PSI reading. For more info, take a look at this section: Checking The Fuel Pump Inertia Switch.
OK, let's get started with this test:
- 1
Place a shop towel under the Schrader valve. The shop towel's job is to absorb any fuel that may leak when doing step 2.
- 2
Install the Ford Schrader valve adapter on the Schrader valve.
- 3
Connect the fuel pressure gauge to the Schrader valve adapter.
- 4
When ready, ask your helper to cycle the key on and off but don't crank the engine while checking for fuel leaks.
If no fuel leaks, go to next step.
If fuel is leaking, resolve the leak before continuing to the next step. - 5
Have your helper to crank the engine while you observe the fuel pressure tester's gauge.
- 6
Your fuel pressure gauge will register one of the two following results:
1.) The fuel pressure gauge will register the indicated fuel pressure specification (see: Fuel Pressure Specifications).
2.) The fuel pressure gauge will NOT register the indicated fuel pressure specification.
Let's interpret your fuel pressure test result:
CASE 1: Gauge reading stays at 0 PSI. This result is telling you the fuel system isn't delivering anything to the fuel injector rail. In other words, the no-start you're troubleshooting is being caused by a total lack of fuel pressure.
This test result usually indicates the fuel pump is toast, but before you condemn the fuel pump as bad, you've got to make sure that it's actually getting power.
On the Ford Escort (Mercury Tracer) this is a piece of cake and this tutorial will help you with that:
On the 1991-1995 Ford Escort and Mercury Tracer, it's a bit more complicated. What you'll need to do is locate the fuel pump fuse and make sure it's not blown. You may also need to check the fuel pump relay before concluding that the fuel pump is toast.
CASE 2: The fuel pressure gauge registered the correct fuel pressure specification. This fuel pressure gauge result lets you know that the fuel pump is working and delivering enough fuel to the fuel injectors.
If your 1.9L Ford Escort (Mercury Tracer) is not starting, it's due to another reason. However, the fuel pump is OK.
TEST 2: Using Starting Fluid
The starting fluid test is one of those old-school tricks that's been in the diagnostic toolbox forever. In fact, it was one of the very first checks I was taught when I started turning wrenches.
This test is especially useful when you don't have a fuel pressure gauge handy. It's not the most precise way to judge fuel pump performance, but it can quickly steer your no-start troubleshooting in the right direction.
One thing you need to keep in mind: this test only works if every spark plug wire is delivering spark. If you haven't verified that yet, make sure all four are sparking before you go spraying starting fluid into the intake.
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
When you have sprayed a good squirt of starting fluid, quickly reconnect the air duct to the throttle body (you don't have to tighten the hose clamp).
IMPORTANT: Reconnecting the intake air duct is a very important safety precaution in case you get a back-fire thru' the intake manifold. - 4
Have your assistant crank the engine once the intake air duct is back on the throttle body.
- 5
You'll get one of two results with this test:
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 find out what your results mean:
CASE 1: Engine started and ran briefly on starting fluid. That's your clue the no-start issue is tied to fuel delivery.
Nine times out of ten, it means the pump has given up. Still, if it were me, I'd back that up by hooking up a fuel pressure gauge before calling the fuel pump bad.
CASE 2: Engine didn't start with starting fluid. That's telling you the problem isn't fuel-related.
In other words, something else is causing the engine to not start, because fuel delivery isn't what's keeping the engine from running.
Just keep in mind: the starting fluid test only tells the truth if you've confirmed all four spark plug wires are sparking. Skip the spark check and the start fluid test results may have you chasing ghosts.
Checking The Fuel Pump Inertia Switch
Your 1.9L Ford Escort (or Mercury Tracer) is equipped with a fuel pump inertia switch. Its job is simple: cut the fuel pump circuit in the event of an impact so the pump shuts down instantly.
When that switch is tripped, you'll either have an engine that stalls out while driving or cranks but won't restart because the pump has no power feed. It's designed to trigger during a serious collision, but I've seen plenty of cases where a minor jolt or bump was enough to set it off.
That's why, before you start blaming the pump or diving into fuel pressure tests, it pays to check the inertia switch first.
On the 1991-1996 1.9L Ford Escort and Mercury Tracer, the fuel pump inertia switch is always on the right-hand (passenger side) rear area of the vehicle. The exact location depends on the body style:
- 3-door and 5-door hatchbacks: Mounted in the right side of the cargo area, just above the wheel well, behind the trim panel.
- 4-door sedans: Located in the right side of the luggage compartment (trunk).
- Wagons: Positioned in the right rear corner of the cargo area, directly behind the wheel well.
Resetting it is straightforward. Press the button on top of the switch until it bottoms out. If it had been tripped, you'll feel a solid click as the button locks back into place —and that restores power to the pump.
More 1.9L Ford Escort And Mercury Tracer Diagnostic Tutorials
You can find a complete list of 1.9L Ford Escort and Mercury Tracer tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Test The MAF Sensor (1991-1995 1.9L Ford Escort, Mercury Tracer).
- Common Causes Of Spark Plug Failure (1991-1995 1.9L Ford Escort, Mercury Tracer).
- How To Test For A Blown Head Gasket (1991-1995 1.9L Ford Escort, Mercury Tracer).
- How To Test Engine Compression (1991-1995 1.9L Ford Escort, Mercury Tracer).
If this info saved the day, buy me a beer!
