Engine rotates but will not start.

Tiny
SKEETPETE
  • MEMBER
  • 1996 MERCURY MARQUIS
  • 4.6L
  • V8
  • AUTOMATIC
  • 150,000 MILES
The car ran fine when I shut it down. The next morning I went to crank it and all it would do was was spin, over, Every thing was turning. But it would not start. It acts like it isn't getting gas to it. We added gas just in case the floater was stuck, But that did not do the trick. Please help us. I was getting gas out of the element rail. Not sure what to call that so I called it the element rail.
Wednesday, February 12th, 2014 AT 9:26 AM

3 Replies

Tiny
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.
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Wednesday, February 12th, 2014 AT 10:02 AM
Tiny
SKEETPETE
  • MEMBER
  • 5 POSTS
I check the spark at left side then the right side cause I have a 4.6 egging. I had no fir coming out of it [not sure I did it right cause I don't have a spark tester. I took out the spark plug on right with a screw driver tride to se if I had fire coming out of them had nothing.
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Friday, February 14th, 2014 AT 6:19 AM
Tiny
WRENCHTECH
  • MECHANIC
  • 20,757 POSTS
Get a spark tester, a fuel pressure gauge and a noid light and complete the rest of the testing and post all of the results.
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Friday, February 14th, 2014 AT 6:39 AM

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