Engine Performance problem
1996 Ford Explorer 4 cyl Four Wheel Drive Automatic 125000 miles
I have been experiencing some problems with starting my ford explorer. I'm not sure what the cause is. At first I thought it was the alternator, so I replaced it and then I found out from a auto repair shop that the fuel pump was bad, I had it replaced also. After that the truck ran pretty well for a few days then went out again. When the key is in ignition and in the start position the humming noise of the fuel pump engaging is not present. I've replaced the fuel pump relay but haven't replaced the fuel filter, can this be the problem? Or would it be some other cause? The check engine light doesn't come on at all during the process and also when turning the key to the start position I hear a click and then it just cranks and not start when I fully turn the key.
All " crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.
Every engine requires spark, fuel and compression to run. That's what we have to look for.
These are the basics that need to be tested and will give us the info required to isolate a cause.
1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.
2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.
3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.
4) If all of these things check good, then you would need to do a complete compression test.
Once you have determined which of these functions has dropped out,
you will know which system is having the problem.