Mechanics

CRANKS BUT WILL NOT TURN OVER

1989 Plymouth Colt • 10,000 miles

One day before this the car just died out while driving, tried to jump it still would not start. 15 min. Later it just started, for one day took it too work and back home no problem. Next day took it to work it just died out would not start, replace fuel filter check fuel pump it seems to work( took it off and put a battery to it it made hum noise)
It is a manual transmission, where do I go from here?
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Doug60
September 3, 2011.




"Cranking" and "turning over" mean exactly the same thing. I assume you means it cranks but won't start.

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.

Wrenchtech
Sep 3, 2011.
Replace fuel pump and filter now the car runs for awhile then cut off
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Tiny
Doug60
Sep 13, 2011.

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