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Problem with a coil pack swap

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Old 10-25-2006, 09:43 PM
  #21  
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Guaranteed if your tach isn't working, you won't have spark. Bill is a good guy, and wouldn't sell you a bunk ICM... unless he didn't test it --bill? The only thing that can cause no spark is crank sensor [which you replaced... but remember if you don't adjust it properly it won't read. If you have any way of putting on a good ICM, that would be your best bet. Does your old magnavox unit work at all? Have anyone with a 3800 you could grab an ICM off or test your'* on?

There is an easy test to check the crank sensor. Hook up a multimeter to it, and set it to the lowest setting... mine and our shop'* units go down to 200mV. That'* what you want.. make sure the voltage oscillates as you crank it over. If nothing happens, your new sensor wasn't adjusted properly. Too close, and it'* garbage, too far and you just need to put it closer to the balancer.
Old 10-25-2006, 10:17 PM
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I have no complaints at all, in my transaction with Bill. One can tell immediately that he is as honest as they come and he delivered on his word, without hesitation. Top notch individual.

As for the crank sensor, My buddy that is a mechanic, actually did the replacement on the sensor the day he brought the diagnostic machine over. He says he has replaced many of these sensors and Im pretty sure we installed it on the exact location on the bracket, of the old one. (he was installing the sensor as I was putting the dash back together from checking the check engine light problem.)

And I guess that is the next thing I am going to pull back off now, to double check if correct. This guy is trustworthy, so It wast him selling me soemthing I didnt need. Hes owed me some favors for a while, and he came over for no charge....

I will post what I find again.

oh yeah...no, i dont know a single person close to me with a working ICM for this car. The on int eh photo came from teh shop my buddy worked at, but he didnt know what it came off of. It had been on a shelf for a little while.. The plug harness was different. :(

Originally Posted by opensourceguy
There is an easy test to check the crank sensor. Hook up a multimeter to it, and set it to the lowest setting... mine and our shop'* units go down to 200mV. That'* what you want.. make sure the voltage oscillates as you crank it over. If nothing happens, your new sensor wasn't adjusted properly. Too close, and it'* garbage, too far and you just need to put it closer to the balancer.
I beelieve I have a voltmeter that goes to 200mV. Where do I check the voltage at? the harness that plgs into the ICM?
Old 10-28-2006, 01:42 AM
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Ok. I got off work late again tonight but being friday, I got out there and checked for voltage from the cranshaft sensor. My meter here:



......does indeed check at the 200mV setting.

I unplugged the sensor plug and the ICM plug and saw they both had a white/red stripe wire and checked for continuity and they were in fact the same wire. So I plugged the sensor connector back in and checked this wire at the ICM plug while my wife turned over the motor with my meter set at the 200mV setting and it was in fact pulsing at 1.5 and then 4.5 as the motor was turning, so this tells me that sensor is installed correctly and working properly

. My problem must be the ICM I bought from BillBoost . I am getting 12 volts at the ICM and getting the pulses from the sensor. I do not know anything else it could be.
Old 10-28-2006, 11:18 AM
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Did you ever check the spark plugs? Please don't rule them out. You've been having trouble for 4+ months. They could be permanently gasoline fouled & I believe they could even destroy the new coils.

Where are you located?
Old 10-28-2006, 11:35 AM
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If the tach doesn't work though, that means the ICM is bad, because the crank sensor checked out at the ICM. And the ICM is getting confirmed voltage. He'* got to get at least another ICM to test out...

MCD: where are you located man... maybe someone lives near you that wouldn't mind helping out.
Old 10-28-2006, 01:23 PM
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I live in the Dallas/Ft Worth metroplex. Ft Worth Texas to be exact.

I pulled the plug wires and used a spare spark plug to check for a spark, so I didnt have to pull the plugs, which by the way, I have already inspected and they are fine.

Hopefully Bill will be able to send me another ICM.
Old 10-28-2006, 01:37 PM
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Sure is hard to get people to look at 6 spark plugs.
Old 10-28-2006, 02:13 PM
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Originally Posted by Technical Ted
Sure is hard to get people to look at 6 spark plugs.
lol I have inspected the plugs a couple of times since this problem started. I have tried everything I know, with the exception of going out and buying everything brand new, to pinpoint the problem.

I understand what you are saying about the plugs possibly being gas fouled, but if I am not getting spark through the wires, it doesnt matter what condition the plugs are in, to be quite honest. The likelyhood of all 3 coil packs being bad and /or all of my wires to suddenly stop transfering the spark is doubtful, at best.

I have been working late the past few weeks so my time has been limited during the week so focusing on the problem at hand has been the priority here. Once I get the problem fixed, I will address other areas such as condition of plugs, oil, & filters, I can assure you.

edit: dont take this to mean that i havent looked at the plugs. I have looked at the plugs. They looked fine. They are less than a year old. Have I pulled every plug out to inpsect it after everytime ive turned the motor over? No, but my somewhat limited mechanical knowledge has afforded me the wisdom to know that it takes a little more than that to foul a plug bad enough to prevent any spark whatsoever.
Old 10-28-2006, 03:20 PM
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Since each coil fires 2 plugs at once I wanted to make sure the plugs weren't shorting out. Example - If plug #6 was shorting out would a good plug in #3 still spark? This is also the only reason I can think of for the coils getting hot.

I liked OSG'* suggestion that the crank sensor may not be centered properly. I've never heard of using a voltmeter to test the sensor & wish he would have gone into more detail. The sensor is actually a dual sensor. How do you know if your testing the 3x or 18x pulse?
Old 10-28-2006, 03:31 PM
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It'* not so much testing that deeply, but what it tests is that the crank sensor isn't too far away [the further away from balancer, the less voltage it produces, then eventually zero volts]. Basically you just hope the crank sensor is doing it'* pulsing job properly, you are just making sure the voltage is good and that it'* an acceptable distance from the balancer.


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