Engine turns but car won't start

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  #1  
Old 04-13-04, 06:04 AM
madesumshoes
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Engine turns but car won't start

Hey,

I have a 1987 Olds Cierra. 156000 miles. It has been running great for about a full year. Yesterday it won't start. The engine turns but seems like no spark or something. Before I start replacing stuff do you think it's the plugs? carburator? Any thoughts.

Thnx
 
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  #2  
Old 04-13-04, 10:01 AM
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not likely to be...

...the plugs and it doesn't have a carburetor. it needs to be checked for no-spark and/or no fuel.

try this...remove the gas cap, stick a funnel in where you put the gas and take a listen as someone turns the ignition on (don't start the engine). you should hear the fuel pump run for about 2-3 seconds and then shut off. if that's ok...then you'll need to buy a spark tester at your local parts store. remove a spark plug wire from a plug and connect the spark tester (they look almost like a spark plug) to the wire and to ground (something metal and clean). have someone crank the engine while you watch the spark tester...it'll be obvious if you have spark. this will get you going in the right direction...post back and we'll give you more to go on.
 
  #3  
Old 04-13-04, 10:11 AM
madesumshoes
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Not exactly sure what I am supposed to hear but seems I heard nothing. No whirring. Is it an abvious whir?
Does this mean I need a fuel pump?
 
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Old 04-13-04, 10:20 AM
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not necessarily...

...altho it's likely.

since you hear nothing and you would know i think...i guess what you could do is do the same test on another vehicle and that will help you be sure. (the vehicle has to be fuel injected...they mostly all have in-tank fuel pumps) it's an electric motor so...yeah...whirring is a reasonable descriptor. it just doesn't last very long...as i said...2-3 seconds.

now...under the vehicle back near the tank, you'll find a connector with 3 wires in it. (colors...gray, purple and black) open the connector and with a test light or a DVOM (digital volt ohm meter), probe the gray wire and have your helper turn on the ignition and you should get voltage...or the test light should light up....for that 2-3 second period. if it does...you need a pump. if it doesn't, we'll have to go back to the relay for further diagnostics.
 
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Old 04-15-04, 08:56 AM
Replica
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In my glorious little opinion...

Old fasioned ignition test method:

Before going through all that, Get yourself an extra spark plug and pull one of your plug wires off of the spark plug (leave it attached to the Distributor cap/Coil pack)

Ground out the bottom of the plug on a good clean body ground (Fender, Firewall) if it lays, fine ..if not ..you get the joy of holding it and hoping the boot isn't cracked ..then have someone turn it over (best to do at night) if you see spark/ get shocked then you've got it coming out to the plugs ...then check your fuel system ...

If you didn't get spark, put your plug wire back on to the actual spark plug and pull off the coil wire from the cap/pak , attach your extra spark plug and repeat the process, if theres no spark from the coil wire then your problem probably lies in the ignition coil (the part you just checked)

If you dont want to get shocked , buy yourself an HEI tester (looks a bit like a sparkplug with a ground clamp)

By the way, when using this method be sure to consider that most iginition systems output voltage in the 20,000 to 22,000 volt range ...low amperage but it could be a cause for concern if you've got heart problems
 
  #6  
Old 04-15-04, 02:22 PM
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Ok, lets make a few corrections here
No, don't use a spark plug, use a spark tester. a spark plug that is not under compression will give you no idea what the strength of your spark is. A spark tester will allow a gap large enough to test the 30-40K capacity of the coil.

If you have no spark, DO NOT blame the coil. There's a good chance you have DIS ignition but since you didn't give an engine size, I can't tell you. If you do have DIS, there is no coil wire anyway. If you have no spark, you need to then test for a reference signal and injector pulse. Use a noid light to check for injector pulse and a spark tester to check for spark and report back with the results and we'll tell you what to do next.

Also note you secondary voltage is more like 40,000 volts, not 20

Let's give the correct advice or none at all.
 
  #7  
Old 04-15-04, 03:51 PM
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Thats right

I recall this spark plug test from school The plug would fire under no pressure but once we put it in a see thru plastic demonstrator and put pressure to it it was dead.
 
  #8  
Old 04-15-04, 03:52 PM
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one other idea

If you had a old fashiond timing light you could clip on to a plug wire and see if the light fires.
 
  #9  
Old 04-15-04, 07:52 PM
DIY4free
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I had a '88 olds calais that did the same thing. If you find you have no spark but fuel the one thing you want to check is the camshaft position sensor (about $20) before replacing more expensive parts. I had a "Quad 4" engine but I believe most GM engines around that year have these sensors in them. (I am not a mechanic so you might want to check with one to find out if this is true for your car.)
 
  #10  
Old 04-16-04, 02:35 AM
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Originally posted by DIY4free
I had a '88 olds calais that did the same thing. If you find you have no spark but fuel the one thing you want to check is the camshaft position sensor (about $20) before replacing more expensive parts.
No, on most GM engines, a cam sensor will not cause a "no start" and they cost a bit more than $20.
Now, if your talking about a crankshaft position sensor, that's a different story, although it usually WILL take out the fuel injectors also.
 
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Old 04-16-04, 09:09 AM
Replica
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Something new every day...

Hehehe ...wow,

Originally posted by Desi501:

Ok, lets make a few corrections here
No, don't use a spark plug, use a spark tester. a spark plug that is not under compression will give you no idea what the strength of your spark is. A spark tester will allow a gap large enough to test the 30-40K capacity of the coil.
Heh, thanks ..I never knew that actually, you really do learn somethin new every day
 
  #12  
Old 04-16-04, 04:37 PM
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No problem, That's what we're here for.
 
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