STEP 2: Testing The Fuel Pump's Pressure
After testing for spark and confirming that all spark plug wires are sparking (which eliminates the ignition system as the cause of the no-start problem), the next step is to ensure that the fuel pump delivers enough fuel to the engine.
Ensuring fuel delivery to the engine means checking the fuel pump pressure with a fuel pressure test gauge and ensuring it's within specification.
The fuel pump pressure for the 1987-1996 4.9L E-Series vans is:
- 50-60 PSI Key On Engine Off (KOEO).
- 45-60 PSI Key On Engine Running (KOER).
The fuel pump pressure for the 1987-1996 5.0L, 5.8L V8 E-Series vans is:
- 35-45 PSI Key On Engine Off (KOEO).
- 30-40 PSI Key On Engine Running (KOER).
You can find the fuel pump pressure test explained in a step-by-step manner here: How To Test The Fuel Pump (Ford E150, E250, E350).
The fuel system is NOT causing the no-start problem if:
- Fuel pressure is within the specified range.
If the fuel pressure gauge registers the indicated fuel pressure specification, then you can confidently conclude that the fuel pump is working and delivering enough fuel to the fuel injectors.
You can also conclude that the fuel pump is not behind the engine's no-start problem.
The next step is to check for a blown head gasket. Go to: STEP 3: Checking For A Blown Head Gasket.
The fuel system IS THE CAUSE of the no-start problem if:
- Fuel pressure is 0 PSI (or anything below the fuel pressure specification).
This confirms that the no-start problem is caused by a lack of fuel. This usually means that the fuel pump is bad and needs replacement.
STEP 3: Checking For A Blown Head Gasket
In most cases, the number one cause of a blown head gasket is severe engine overheating.
Testing for blown head gasket involves performing one of four tests. Two of those tests don't require any tools and can be done in under 5 minutes.
I've written a tutorial that will help you with these four tests, and you can find it here:
A blown head gasket is NOT causing the no-start problem if:
- The engine oil has a normal color (in other words, it doesn't have a milky-white color).
- The coolant in the radiator remains undisturbed when cranking the engine (with the radiator open).
- The engine passed a block test.
Your next test is to check the engine's compression. Go to: STEP 4: Making Sure The Engine Has Good Compression.
A blown head gasket IS THE CAUSE of the no-start problem if:
- The engine oil has a milky-white color (like coffee with too much creamer).
- - or -
- The coolant in the radiator shot out when cranking the engine (with the radiator open).
- - or -
- The engine failed a block test.
STEP 4: Making Sure The Engine Has Good Compression
The engine compression test is probably one of the most overlooked diagnostic tests when it comes to troubleshooting an engine no-start problem.
If you have eliminated the ignition system, the fuel pump, and a blown head gasket as the causes of the no-start problem, then the next step is to test engine compression.
An engine compression problem is NOT causing the no-start problem if:
- The compression of each cylinder is above 120 PSI.
An engine compression problem IS THE CAUSE of the no-start problem if:
- 2 or more cylinders have 0 PSI compression.
- - or -
- All cylinders have 0 PSI compression.
No-Start Troubleshooting Summary
Troubleshooting and finding the cause of your Ford E150 (E250, E350) van's engine no-start problem boils down to a simple process of elimination. The objective here is to find out what is missing from the mix the engine needs to start.
Keep in mind, as you troubleshoot the problem, that the engine needs three things to start:
- Spark.
- Fuel.
- Air (compression).
Once you've confirmed that all cylinders are receiving spark, there isn't any need to spend time testing any ignition system components. The next step is to make sure the fuel pump is working and so on and so on.
By checking these basic things (spark, fuel, air), you'll save yourself the frustration of replacing components that won't solve the problem.
More Ford E150, E250, and E350 Tutorials
You can find a complete list of tutorials for the full-size Ford E-Series vans here: Ford 4.9L, 5.0L, 5.9L Index Of Articles.
Here's a small sample of the tutorials you'll find:
- Manifold Absolute Pressure MAP Sensor Test (Ford 4.9L, 5.0L, 5.8L).
- Ignition Coil Test -No Spark No Start Tests (Ford 4.9L, 5.0L, 5.8L).
- How To Troubleshoot A No Start (Ford 4.9L, 5.0L, 5.8L).
- Testing A Blown Head Gasket (Ford 4.9L, 5.0L, 5.8L).
- How To Test Engine Compression (4.9L, 5.0L, 5.8L).
If this info saved the day, buy me a beer!
