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2000 chevy Malibu cranks but won't start
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sjwanderer
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Aug 10, 2011, 4:24 PM
Post #1 of 12
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2000 chevy Malibu cranks but won't start
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I have a 2000 Malibu LS 6 cyl w/ about 105k on it that will not start. Cranks over like crazy and will not start, currently. But that I think is only one symptom of many for a single problem which I believe to be a wiring issue but need some more direction. So let me describe what has been going on over the last 18 months or so.
* First notice in the colder months the ABS light would come on when braking. Thought it was just ice on the road messing with it because they still worked.
* Shortly, within days, when braking notice the lights would dim both internal and external, blower fan would slow and sometimes the radio would cut out.
* I changed the battery out because as the previous one was being tested they hooked it up incorrectly and exploded it even though they said it was 'good'.
* about one month after I changed the battery and cables the car would crank over but not start occasionally. Wait a minute and then it would start. No theft light and only waited 30-60 seconds and it would start right up.
* After doing this for about 6 months, June now and hot outside, the car just wouldn't start one morning. No theft light and no error codes in the computer.
* I started just poking and prodding at it with a meter and o-scope and found nothing wrong according to the chiltons manual.
* One day after a couple of weeks of tearing into this thing it just started. So I left the car running and got out to think what I had just done and find the final answer. As I stood there contemplating the future of the car I heard a click, kind of like a relay kicking out, and it died and would not start again for about three days.
* This random start and then stop, with the click, continued over the weeks while I replaced the ICM, coil pack and ignition switch.
* Finally replaced the Crankshaft position sensor that was between the block and transmission. It started and ran, no click and die. Kept trying it in the mornings and afternoon after some days I decided this was the fix so I started driving it again.
* A month or two later the power drain started again then one day it died and was starting to dig it's own hole as the whole process started over. I of course started with CP sensor and wiring.
* I finally broke down and sent it to a shop and after $700 and a new ignition switch, claiming it was the anti-theft system although the light never came on but it ran so OK, I guess.
* about 7 months later summer again it died and would not start
* I ignored the car for the most part but every week or two I would try it without really trying to 'fix' it. After about 6 weeks it started and kept running with out issues
* after a few days of trust exercises I started to drive it normally again about a week ago it died again.
Here is what I've learned:
- First my car likes me because it has always died in my driveway or my garage after sitting for at least a few days but as much as two weeks.
- If the key cylinder is removed a 3/8th inch extension can be used to start the car and will work in place of the key.
- attempting to bypass the anti-theft system is a waste of time as that is not the cause at least not that the computer acknowledges.
- The power drain issue usually disappears a few days before it dies.
A friend had recommended I try the alternator but that doesn't sound right and I have tried a computer out of a car in a junk yard but if this was a cracked board you would think that during the cool nights it would start but maybe not during the hot days or very cold days. Also what about that relay click during the first session when I heard that I started rotating relays with a new one in the mix on the first go around. ANY Thoughts would be very helpful. Thanks, SJ
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Hammer Time
Ultimate Carjunky
/ Moderator
Aug 10, 2011, 4:33 PM
Post #2 of 12
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Re: 2000 chevy Malibu cranks but won't start
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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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Discretesignals
Ultimate Carjunky
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Aug 10, 2011, 4:33 PM
Post #3 of 12
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Re: 2000 chevy Malibu cranks but won't start
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When it dies and doesn't want to start again you need to check these things.
Does it have fuel pressure? You have to connect a fuel pressure gauge up.
Does it have spark? You can use an inline spark tester or equivalent.
If you have a code reader can you communicate with the PCM?
Once you find out what is missing, then you can diagnose that system to isolate the problem.
HT beat me to the punch...copy and paste function works great..
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
(This post was edited by Discretesignals on Aug 10, 2011, 4:35 PM)
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sjwanderer
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Aug 10, 2011, 5:05 PM
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Re: 2000 chevy Malibu cranks but won't start
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No spark as I hope I pointed out but might have missed. I also have injector pulse as I put an Oscilloscope on it to measure amplitude and width (yes I happen to have one laying around from engineering school). Fuel pressure is good, and so is compression. Like I mentioned it has to be some sort of wiring problem but not sure where to start troubleshooting as all the signals that the Chiltons manual says should be there are.
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sjwanderer
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Aug 10, 2011, 5:08 PM
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Re: 2000 chevy Malibu cranks but won't start
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As I mentioned no codes in the computer and yes it does communicate with the PCM as I can generate a code by pulling the airbag fuse and get the codes for that. For the rest see my previous reply. As I seem to have done all the standard troubleshooting mentioned and made sure I covered my bases covered in the copied and pasted messages. Sorry, I understand for the replies but a little frustrated too.
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sjwanderer
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Aug 10, 2011, 5:55 PM
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Re: 2000 chevy Malibu cranks but won't start
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I have only checked a couple of cylinders for spark and as I recall do have battery voltage at the coils, but will check all coils and cylinders again as it has been a few months since I checked them. thanks.
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sjwanderer
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Aug 10, 2011, 7:06 PM
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Re: 2000 chevy Malibu cranks but won't start
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Ok, first it is dark out so the head lamps came on automatically. And here is some info that might help...
before I did anything I tried to start it no luck. turned ignition all the way off. Pulled the 2-5 coil. Accidentally turned key all the way over and engine started. Turned off all the way and measured voltage at coil pins. 12v on one and .6 on the other between engine block. .38v between the two pins. Coils are only about 8 months old but????
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Discretesignals
Ultimate Carjunky
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Aug 10, 2011, 7:28 PM
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Re: 2000 chevy Malibu cranks but won't start
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The pin that doesn't have power is used by a transistor in the module to complete the coil circuit to ground. There is a transistor for each coil.
The transistor is controlled by the logic in the ignition module. The ICM recieves a 7x signal from the crank sensor you changed on the back of the engine. The ICM not only uses that signal to time the transistor to fire, but also converts that 7x signals to a 3x signal that is sent to the PCM. The 7x sensor is a PM generator and as you know generates an ac voltage. Be sure the twisted yellow and purple pair didn't find its way into the exhaust manifold or egr feed tube.
During cranking the logic in the ICM controls the transistors. Once the idle speed comes up high enough the PCM grounds 5 VDC bypass circuit that closes another transistor in the ICM. This transistor closes a circuit that allows the PCM to take control of the ignition timing and dwell.
Just to let you know, the ICM will fire the coils while cranking even if the PCM is unplugged. That's unless there is a bypass problem where the bypass is stuck closed and allowing the PCM take control (very rare).
You have to make sure you check this when the problem is occurring, of course.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
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sjwanderer
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Aug 10, 2011, 7:33 PM
Post #10 of 12
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Re: 2000 chevy Malibu cranks but won't start
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Forgot to mention a couple of things before I pulled the coil I had no spark on any of the cylinders. As I mentioned earlier I was able to try a new ICM in an earlier post but managed to get the part store to take it back for store credit so the one on there is original w/ the car. I was unable to continue working on the car as the neighborhood nazi was making sure I was not working on the car after the rules allow so I couldn't put the coil back on and test but will try tomorrow and even swap the coils around and see if I get the same results.
I'm starting to think that it is one of three things: one of the new coils, the ICM or the PCM, any thoughts?
oops didn't see your post before I did this so I will post more information tomorrow thanks for the schematic that helps a lot.
(This post was edited by sjwanderer on Aug 10, 2011, 7:36 PM)
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Discretesignals
Ultimate Carjunky
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Aug 10, 2011, 7:37 PM
Post #11 of 12
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Re: 2000 chevy Malibu cranks but won't start
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Read the post above.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
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sjwanderer
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Aug 11, 2011, 2:47 PM
Post #12 of 12
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Re: 2000 chevy Malibu cranks but won't start
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Back on hold as after I put it all back together again it started up without issue so I guess I have to wait until it dies again. At least if it doesn't die in the driveway I have towing coverage.
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