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dbass
New User
Jul 28, 2013, 6:50 AM
Post #1 of 4
(2497 views)
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2002 pontiac sunfire cranks no start . got no spark.changed ingtion coil plugs and wires. it has an 2.2 leater overhead cam. changed crank postion sensor. car gets fuel.
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Hammer Time
Ultimate Carjunky
/ Moderator
Jul 28, 2013, 6:59 AM
Post #2 of 4
(2483 views)
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Re: cranks no start
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You need to complete the rest of this testing and post the results here. Testing spark alone won't tell us enough
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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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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dbass
New User
Jul 28, 2013, 7:06 AM
Post #3 of 4
(2481 views)
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Re: cranks no start
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the car has compresson. timming chain good. checked wire harness from crank sensor and pcm.
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Discretesignals
Ultimate Carjunky
/ Moderator
Jul 28, 2013, 10:26 AM
Post #4 of 4
(2458 views)
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Re: cranks no start
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If you follow that procedure above, it will help paint a clearer picture of what is going on.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
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