2004 Mustang Cranks But Wont Start All The Way

DUMMYY

MEMBER
2004 FORD MUSTANG
3.8L
6 CYL
2WD
AUTOMATIC
110,000 MILES

I have a 2004 Mustang V6, 3.8 L. I drove my car to a friend's house yesterday fine and when I tried to leave I tried to start it and it would not turn over all the way. It makes the "r-rrr-rrr-rrr" noise but won't make the "Vroom" noise where I can fully start it. I tried jumping it 3 times but that did not work. Everyone is telling me that it is not the starter because the engine would not crank at all. I tested listening for the fuel pump and I could hear it turn on. I tried disconnecting the connectors to the battery because it might be a theft problem but that did not work. I am kind of stuck now. If anyone has any ideas that would be great. Thanks!

1 Reply

WRENCHTECH

MECHANIC
20,757 POSTS

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.