1993 Buick, two pistons not firing (Distributorless Ignition System question)

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tfurrows@gmail.com - 05 Jan 2006 19:48 GMT

Anyone,

I am repairing my 1993 Buick Regal Custom, 3.8L. I left it running when
I went into the store the other day, then when I drove it away it was
running rough. A timing gun revealed that 2 pistons weren't firing.

The car uses a Distributorless Ignition System, and has 3 ignition
coils to power the 6 cylinders (firing 2 at a time). My first thought
was to try repalcing the cables running from the coil to the spark
plugs. This did nothing. My second thought was to replace the one coil
that wasn't firing. This did nothing, the new coil also didn't fire.

Next in the logical line is the Distributorless Ignition Module.
Unfortunately this is a $80-$300 part, and I would like to be sure this
will solve the problem before I run off an buy one. My questions are
these:

1. Should I be testing the crank position sensor, and is it possible
that it could be damaged in such a way that it would somehow only
trigger 2 of the coils?
2. Could wiring be to blame?
3. Could the computer be to blame?

The module would be easy to repalce (only a few bolts), but the cost
leads me to ask these questions first. Any help would be greatly
appreciated! Many thanks in advance.

Joe
tfurrows -a-t g,mail

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Shep - 05 Jan 2006 22:36 GMT

Are the cylinders not firing paired on the same coil? You left that out.

> Anyone,
>
[quoted text clipped - 25 lines]
> Joe
> tfurrows -a-t g,mail

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Rich - 06 Jan 2006 01:00 GMT

Joe,

Can you get a code reader to pull out the codes that are set? I had
an 1992 Olds with a 3.8 engine and when I had a crank sensor problem
the codes pointed me to the sensor. Unfortunately the codes also
pointed to the cam sensor as well as the crank sensor. Of course the
ignition module is tied into the hole mess.

I ended up buying the ign module ($$$ like you said) but the problem
turned out to be the crank sensor. Now I have an expensive electonic
brick I can't use.

You may save yourself time and money in the long run by taking the car
to someone who can diagnose reliabily the problem. The operative
work is 'reliabily".

Are the two affected cylinders on the same coil? If so you can swap
coils and see if the problem moves to follow the suspect coil.

If you are convinced that the problem is the ignition module, contact
me.

Rich
grstidge at localnet dot com

>Anyone,
>
[quoted text clipped - 25 lines]
>Joe
>tfurrows -a-t g,mail

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gobroncos - 06 Jan 2006 13:32 GMT

I think its worth throwing an ignition module at it, but not at $300.
Purchase one from a junk yard; they are usually garaunteed for 90 days
if they fail. Drawback is that they will usually not refund your money,
but will give you credit for your purchase. This isn't necessarily bad,
noting that you have an older vehicle that might benefit from that
credit. Shop around, but definately contact Rich. Jim

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gobroncos - 06 Jan 2006 19:18 GMT

With the given symptom that only one of the three is not being fired,
and the plug wores/plugs have been replaced, the answer to all three of
your questions would be NO! Coil primary circuits are activated from
within the ignition module itself. To avoid spending alot of money,
replace the ignition module with one from a junkyard (usually
garaunteed for 90 days.) Avoid the HYPE... Your car ran just fine on
used parts till now. Jim

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