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V6 eating ignition control modules way too fast by Leithal
Started on: 03-17-2004 04:17 AM
Replies: 24
Last post by: Leithal on 03-22-2004 03:40 AM
Leithal
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Report this Post03-17-2004 04:17 AM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post

Hello, need some advice on a recurrent problem. I have now gone through 6 ignition control modules and 2 pick up coils in less than a year on my 86 GT. For 5 years this car has been reliable, but now it's leaving me stranded on a regular basis and costing me a fortune. I need to solve the underlying problem. I do have a Jacob's Ignition system, but I've had it for 4 years, the first 3 without incident.
The cap and rotor are new. Suspects: I had wondered if high resistance wires could feedback and burn out the modules, but an ohmeter proved they were within factory tolerances. Next I was wondering if the alternator internal voltage regulator was shot, could it overcharge the entire sytem.....will check as soon as I get the darn thing running again.

What other ideas do people have???

Many thanks,

Leith

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Report this Post03-17-2004 05:16 AM Click Here to See the Profile for GTDudeClick Here to Email GTDudeDirect Link to This Post
High resistance is what usually causes modules to smoke. This could be bad plugs, wires, cap, coil, rotor. Of course, if you're using cheap modules, I GUARANTEE it's the module themselves. Use a GM or Borg Warner, or Echlin (NAPA).

Phil

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GM auto tech for 27 years. Specializing in electrical and computer problems. Now on workers comp. and it looks like I will be unable to return to work as a tech.

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Report this Post03-17-2004 09:40 AM Click Here to See the Profile for Steve NormingtonClick Here to Email Steve NormingtonSend a Private Message to Steve NormingtonDirect Link to This Post
You are using heat-sink compound when you put in the new module, correct?

Have you checked the gap on your plugs?

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Report this Post03-17-2004 12:16 PM Click Here to See the Profile for Formula88Send a Private Message to Formula88Direct Link to This Post
 
quote
Originally posted by Steve Normington:

You are using heat-sink compound when you put in the new module, correct?

Have you checked the gap on your plugs?

The heat-sink compound cannot be over emphasized. Without it, you will burn modules in short order. If you didn't get any with the replacement module, go to Radio Shack and buy a small tube of heat sink grease. It the kind used on PC CPU's when you put a heat sink on.

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Report this Post03-17-2004 12:51 PM Click Here to See the Profile for prof boboClick Here to visit prof bobo's HomePageClick Here to Email prof boboSend a Private Message to prof boboDirect Link to This Post
Hmmm, has anyone done/considered relocating the module and mounting a big heatsink on it, perhaps even with its own fan? Seems like that would be really easy to do, make it more reliable and easier to fix if it were to fail.
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Dave Gunsul
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Report this Post03-17-2004 11:11 PM Click Here to See the Profile for Dave GunsulSend a Private Message to Dave GunsulDirect Link to This Post
 
quote
Originally posted by Steve Normington:

You are using heat-sink compound when you put in the new module, correct?

Have you checked the gap on your plugs?


I'm glad someone else mentioned this. I changed the gap on my plugs once when i upgraded the ignition and all the sudden i was burning modules. When i went back to the stock 45 gap it stopped happening. This will especially happen with the cheap modules.

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Leithal
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Report this Post03-17-2004 11:43 PM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post
Hmmmm, I wondered about gap. As per the Jacob's instructions my gap is set at .065. It has been set at this for 4 years, 3 without incident.

Does anyone know of a way to test the actual modules?

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Electrathon
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Report this Post03-17-2004 11:58 PM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageClick Here to Email ElectrathonSend a Private Message to ElectrathonDirect Link to This Post
 
quote
Originally posted by Leithal:


Does anyone know of a way to test the actual modules?

There is a GM tool that does this. The easiest backyard way is to replace it.

It can not be stressed enough that low quality modules will constantly fail when good ones will not.

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Leithal
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Report this Post03-18-2004 12:50 AM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post
So people really think the "non GM" modules I am buying could be the problem??? We are talking about each module lasting about 2 months, the last only 4 weeks! Are they really THAT bad????

[This message has been edited by Leithal (edited 03-18-2004).]

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Electrathon
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Report this Post03-18-2004 01:09 AM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageClick Here to Email ElectrathonSend a Private Message to ElectrathonDirect Link to This Post
 
quote
Originally posted by Leithal:

So people really think the "non GM" modules I am buying could be the problem??? We are talking about each module lasting about 2 months, the last only 4 weeks! Are they really THAT bad????

That bad and worse. They are usually guarantied for life so a lot of people carry another to swap in beside the freeway. I would lean twords just getting a good one once. If there is any part that you DO NOT want from Autozone, this is it. There are good aftermarket ones, just make sure it is a major name brand. It is very important to have the dielectric grease under the module too.

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Leithal
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Report this Post03-18-2004 03:57 AM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post
I have been buying "Standard" brand modules, p.n. LX-340. What's the verdict on these???
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Report this Post03-18-2004 12:25 PM Click Here to See the Profile for Two88GTsClick Here to Email Two88GTsSend a Private Message to Two88GTsDirect Link to This Post
The Standard brand stuff are definitely below my standards.

The cost differential between a AC Delco one and aftermarket is minimal. Go with AC Delco.

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Report this Post03-20-2004 07:05 AM Click Here to See the Profile for -=shame=-Click Here to Email -=shame=-Send a Private Message to -=shame=-Direct Link to This Post
I don't want to discredit any of the suggestions made, I just wanted to add, how's your alternator? I had a surging alternator smoke an ignition module as well as a coil. While many may say that that is impossible and that each is protected from a power surge, replacing the alternator is what fixed the problem after the second set of ignition module and coil.
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Report this Post03-20-2004 08:29 AM Click Here to See the Profile for $Rich$Click Here to Email $Rich$Send a Private Message to $Rich$Direct Link to This Post
both our local autozones have a machine tha tests the module and they do it for free
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Report this Post03-20-2004 10:20 AM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolDirect Link to This Post
 
quote
Originally posted by Electrathon:


It can not be stressed enough that low quality modules will constantly fail when good ones will not.

I can't fully agree with this. Upon the failure of my second module in 2 years, just down the street from a Pontiac dealer, I sprung for the $70 GM module. It lasted about a month. I reinstalled one of the $28 Welles that had previously failed and it worked. Now, I just rotate the 2 spare Welles modules. When one fails, I put the other failed one in and it runs again. The GM module hasn't recovered.

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Report this Post03-20-2004 11:02 AM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageClick Here to Email ElectrathonSend a Private Message to ElectrathonDirect Link to This Post
 
quote
Originally posted by fierofool:


I can't fully agree with this. Upon the failure of my second module in 2 years, just down the street from a Pontiac dealer, I sprung for the $70 GM module. It lasted about a month. I reinstalled one of the $28 Welles that had previously failed and it worked. Now, I just rotate the 2 spare Welles modules. When one fails, I put the other failed one in and it runs again. The GM module hasn't recovered.

It sounds like you have a connection problem. When you replace the module you are moving/wiggling things. I would very carefully inspect the tension on the connectors that hook up to the module. It is not uncommon for the terminals to seem good, but be barely making contact. Modules are solid state parts with the electronics glued in place, they are not going to "heal" themselves.

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Report this Post03-20-2004 11:17 AM Click Here to See the Profile for Dave GunsulSend a Private Message to Dave GunsulDirect Link to This Post
 
quote
Originally posted by Leithal:

Hmmmm, I wondered about gap. As per the Jacob's instructions my gap is set at .065. It has been set at this for 4 years, 3 without incident.

Does anyone know of a way to test the actual modules?


Although i do believe that the module you have is not a good one to use, i think you need to knock that gap down. You're not supposed to jump the gap up that far. The stock gap is 45 so, normally, all you'd go up to would be 50. I think that you will keep poping modules with the gap like that even if it is a GM module. The GM module, being better, has survived longer but i'd bet that's why it failed too.
So, in my opinion, i would suggest the following: Put the gap back to at least 50 and replace the module with a GM one. When i changed the gap i started burning modules and when i changed it back this stopped happening. When i did this, i put in a few modules and the GM units always lasted longer then the others. Once i changed the gap back to 45 it never happened again. I'd still suggest using the GM modules though. During the time my car had the wider gap i used a few different modules and all of the used GM modules i used lasted longer then the brand new aftermarkets did.
Also; always carry a spare module and the tools to change it in your Fiero. It's the only part that really breaks unexpectantly and it can be changed in no time on the side of the road.
I always carry a spare and have even saved other Fiero owners with that spare.

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Report this Post03-20-2004 02:48 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolDirect Link to This Post
Electrathon, I've checked the connector plugs. The clips are there and the connection is pretty difficult to separate once the car's been run for a while. The last time I had to swap out, I mistakenly put the same module back in, and it still wouldn't start. The GM module failed once and that was the end. On the other hand, my 85 lost a module at about 150K miles, and it's now on the replacement at 283K miles. The clips on both connectors are broken, and the only thing that holds them in the module is the rubber seal.

I really think the problem with the 87 is possibly the tach filter, since the whole distributor was replaced, and the modules still continued to fail. But I agree that loose connections can kill the module.

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Report this Post03-20-2004 04:08 PM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageClick Here to Email ElectrathonSend a Private Message to ElectrathonDirect Link to This Post
What you need to check is the terminal preasure on each individual connection. You have to disconect the plastic conector and then probe each metal terminal individually. Be very carefull not to probe it with anything of any size. Usually something about the sixe of a small safety pin will work (there is actually a tool that does this it is so common). It is common to find one that has colapsed.
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Leithal
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Report this Post03-20-2004 10:40 PM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post

Well my car's ripping again. The place I bought the last module at gave me a free replacement, so I'll stay with Standard on this one. If it dies out again I'll go to an AC Delco one, though several people have told me many of the brands are identical, just sold under different names, AC Delco included. For interests sake I'll mention that I do think my alternator has been the problem. I determined it is putting out 14.6 volts. The internal voltage regulator must be shot because it is supposed to limit it to a max of 14.2 volts. It likely spikes when underload or whilst driving, so I am totally willing to bet it was responsible. Time will tell. Now, back to installing a new alternator.....

Oh and thanks everyone for your advice, I appreciate it.

Leith

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Report this Post03-20-2004 11:34 PM Click Here to See the Profile for ToddsterClick Here to Email ToddsterSend a Private Message to ToddsterDirect Link to This Post
my money is on a bad pick-up coil (the thing that plugs into your module. Once they go, you're toast. To replace it you really need to remove the disty and rebuild it. Not too much trouble but a sand blaster is essential it remove the varnish from the shaft.
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Report this Post03-21-2004 12:38 AM Click Here to See the Profile for Steve NormingtonClick Here to Email Steve NormingtonSend a Private Message to Steve NormingtonDirect Link to This Post
 
quote
Originally posted by Dave Gunsul:

Also; always carry a spare module and the tools to change it in your Fiero. It's the only part that really breaks unexpectantly and it can be changed in no time on the side of the road.
I always carry a spare and have even saved other Fiero owners with that spare.

Replace the hex head screws that hold the module down with phillips headed screws. Then the only tool you'll need is a phillips screwdriver (which you need anyway to remove the distributor cap).

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Electrathon
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Report this Post03-21-2004 01:25 AM Click Here to See the Profile for ElectrathonClick Here to visit Electrathon's HomePageClick Here to Email ElectrathonSend a Private Message to ElectrathonDirect Link to This Post
 
quote
Originally posted by Leithal:


For interests sake I'll mention that I do think my alternator has been the problem. I determined it is putting out 14.6 volts. The internal voltage regulator must be shot because it is supposed to limit it to a max of 14.2 volts.
Leith

14.6 is considered perfect charging voltage. I always considered 14.2 a slight undercharge, but acceptable. Page 6D9 of the 86 manual lists 13.5 to 16.0 proper charging. Save your money on the alternator.

One interesting thing on parts stores telling people that the parts are all made by the same place. Look at them closely, they are almost always obvious that they are from a differant manufacture. Then break some open, they are totally differant inside. I have heard that some of the parts that function but are out of spec for GM are repackaged and sold to other wholesalers. That is where the rumor got started that they come out of the same factory.

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Report this Post03-21-2004 07:23 AM Click Here to See the Profile for -=shame=-Click Here to Email -=shame=-Send a Private Message to -=shame=-Direct Link to This Post
Agreed, half of a volt wouldn't do it. Not even two or three. I should have described what my alternator was doing in more detail. It was spiking enough to pin the needle and make it look like I had my high-beams on. Exactly how much it was putting out I don't know, it never did it in idle while parked. I should add it was also blowing out light bulbs.
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Leithal
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Report this Post03-22-2004 03:40 AM Click Here to See the Profile for LeithalClick Here to Email LeithalSend a Private Message to LeithalDirect Link to This Post
There are several people I trust who all think 14.6 is too high (yes I know what the factory manual reads...the factory isn't always right). I do think it very likely my alternator has been the problem; all the symptoms point too it. Just because I didn't detect any large spikes at idle doesn't mean they're not there during driving or under load. Anyway, the alternator looked original, cost only $100 Canadian bucks, and didn't take me long to do. Time will tell, but I suspect it has been my problem all along.
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