new coils, oh my what power
06-24-2009, 01:24 PM
#31
Rennlist Member
06-24-2009, 01:45 PM
#32
Rennlist Member
I never call Autohous AZ, but ordered via the website many times, they ship the same day. Just got dist caps, rotors and plugs from them two weeks ago.
06-24-2009, 02:18 PM
#34
"I just thought until now that if they worked, they worked."
That's exactly correct!
The exceptions are:
1. The coil is dead - determined by a simple disconnect of the other ignition module
for the second coil.
2. The coil is breaking-down (HV internal problem) - determined by random misfires and
eliminated by just using one of the two ignition systems, i.e. disconnect a module.
3. The coil generating RF noise (causing random DME fault codes & poor running) -
eliminated by just using one of the two ignition systems, i.e. disconnect a module.
The 964 with dual ignitions facilitates ignition troubleshooting and localizing problems.
The probability of both coils being bad is extremely low. Use of the above can usually
determine this case. The key point to remember is that there's just a minimum voltage
required for ignition and additional voltage, e.g. aftermarket junk, usually just shortens
the life of the whole ignition systems, e.g. caps, rotors, plug ends, & wiring.
Bottom line: If the ignition system is working properly, don't waste money on it.
Just use the money for a carbon fiber shift ****. You'll "see" your money every
time you shift.
That's exactly correct!
The exceptions are:
1. The coil is dead - determined by a simple disconnect of the other ignition module
for the second coil.
2. The coil is breaking-down (HV internal problem) - determined by random misfires and
eliminated by just using one of the two ignition systems, i.e. disconnect a module.
3. The coil generating RF noise (causing random DME fault codes & poor running) -
eliminated by just using one of the two ignition systems, i.e. disconnect a module.
The 964 with dual ignitions facilitates ignition troubleshooting and localizing problems.
The probability of both coils being bad is extremely low. Use of the above can usually
determine this case. The key point to remember is that there's just a minimum voltage
required for ignition and additional voltage, e.g. aftermarket junk, usually just shortens
the life of the whole ignition systems, e.g. caps, rotors, plug ends, & wiring.
Bottom line: If the ignition system is working properly, don't waste money on it.
Just use the money for a carbon fiber shift ****. You'll "see" your money every
time you shift.
06-24-2009, 05:33 PM
#35
Three Wheelin'
Just curious, how many miles were on your car when you changed the coils dutchcrutch?
I wonder if these things break down with age or mileage (or both?) My car is 16 years old w/25K miles- I think I'll leave well enough alone as it runs Great!
Once I changed the coil with another bosch unit in my VW and it ran like crap, so the old one went back in (I think the VW place sent us the wrong type of coil?) Anyway, never messed with it again...
I wonder if these things break down with age or mileage (or both?) My car is 16 years old w/25K miles- I think I'll leave well enough alone as it runs Great!
Once I changed the coil with another bosch unit in my VW and it ran like crap, so the old one went back in (I think the VW place sent us the wrong type of coil?) Anyway, never messed with it again...
06-24-2009, 06:01 PM
#36
Rennlist Member
Thread Starter
coils
my car 1990 has 21000 miles on it. back some time ago i got to know the car and found that it would not run on 1 coils for long and would die. found which ignition circuit it was and began to trouble shoot. turns out that a ignition wire was toast. also that lug where that ignition wire went on the distributor cap was all corroded. replaced the caps and rotor including that 1 wire and was able to get the car to run on either coils no problem.
i have worked on many cars since i was young and dealt with distributor caps a plenty mostly bosch caps. to make a long story short bosch is clear coating the ignition lugs gor the wire connection in manufacturing which i have never seen till this day and i believe this was the cause of that ignition wire failure and in turn caused the corrisponding coil to start failing inside. i do not want to go round and round on this but those who have bought new caps a simple continuity check of the exterier pin will validate what i am saying. detailed cleaning with scotchbrite and alcohol fixed it. if you do not clean it off you are hoping that when you install the ignition caple on the cap the wire will hopefully scrap off that area and make a connection. if you look inside the ignition wire that goes onto the cap it not a solid 360 degree contact area, but a wire, so a solid connection is important. take this info for whats its worth, i know better. no one would try to make a connection on a coated surface if it could be avoided.
my home is located down a hill so everytime i take the car for a drive it seem to always struggle a bit when going up, mind you not real bad but it was there. the car i thought always drove well. but after the coil change it was like night and day and it went up the hill without the slightest hesitation and just wanted to go go go.
i helped another rennlister that could not get his car to run on either coil and after he cleaned up the pins real well, that coating is hard to come off, his car would run on either coil.
i have worked on many cars since i was young and dealt with distributor caps a plenty mostly bosch caps. to make a long story short bosch is clear coating the ignition lugs gor the wire connection in manufacturing which i have never seen till this day and i believe this was the cause of that ignition wire failure and in turn caused the corrisponding coil to start failing inside. i do not want to go round and round on this but those who have bought new caps a simple continuity check of the exterier pin will validate what i am saying. detailed cleaning with scotchbrite and alcohol fixed it. if you do not clean it off you are hoping that when you install the ignition caple on the cap the wire will hopefully scrap off that area and make a connection. if you look inside the ignition wire that goes onto the cap it not a solid 360 degree contact area, but a wire, so a solid connection is important. take this info for whats its worth, i know better. no one would try to make a connection on a coated surface if it could be avoided.
my home is located down a hill so everytime i take the car for a drive it seem to always struggle a bit when going up, mind you not real bad but it was there. the car i thought always drove well. but after the coil change it was like night and day and it went up the hill without the slightest hesitation and just wanted to go go go.
i helped another rennlister that could not get his car to run on either coil and after he cleaned up the pins real well, that coating is hard to come off, his car would run on either coil.
06-25-2009, 04:00 AM
#39
Rennlist Member
Thread Starter
cap
all connection on the cap.
one thing i forgot to mention is that it is important to get the car to run on either ignition circuit independently before you replace any thing. i have talked with a few people that did not know their car would not run on just one circuit or cannot get the car to run on either just the lower or upper plugs. if you do not do this your wasting your time and money.
one thing i forgot to mention is that it is important to get the car to run on either ignition circuit independently before you replace any thing. i have talked with a few people that did not know their car would not run on just one circuit or cannot get the car to run on either just the lower or upper plugs. if you do not do this your wasting your time and money.
07-05-2009, 06:58 PM
#41
New coils works for me too!
Have a 94 C2 with 27k and wong chip...and wevo mounts and bypass cat which with new coils seems to be more spirited, idles better when warm, and gets up and goes at lower rpms than before the new coils. I have to say it did seem to help things a bit and the coils were 16 yrs old.
07-05-2009, 08:48 PM
#42
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Location: Raeford, North Carolina
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I am going to replace my coils as well in my 89 C4 with 75K miles on her. I ordered them last week, should be getting here tomorrow, I will let you all know there is an improvement. I have also been having the laging issues and poor idling 1% of the time.
07-06-2009, 05:40 PM
#43
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Just finished install this morning, not a huge amount of difference, but I can tell that there is some extra oomph that was not there before.
+1 for replacing coils.
+1 for replacing coils.
07-07-2009, 12:16 PM
#44
"Just finished install this morning, not a huge amount of difference, but I can tell that there is some extra oomph that was not there before."
So, some may think their actions will result in a positive direction long term
by a simple part replacement, i.e. a new part is always better than an old
one, right? Well, many will learn the hard way that that isn't always the case,
as some replacement parts, e.g. the silver Bosch coils, aren't as reliable as
the original black Bosch coils used initially.
This may be more problematic for 964 owners because of the dual ignition
system and the potential for the silver coil's intermittent operation and thus
the less likelihood of notice by the owner.
Bottom line: In many case it's better to "leave well enough alone".
So, some may think their actions will result in a positive direction long term
by a simple part replacement, i.e. a new part is always better than an old
one, right? Well, many will learn the hard way that that isn't always the case,
as some replacement parts, e.g. the silver Bosch coils, aren't as reliable as
the original black Bosch coils used initially.
This may be more problematic for 964 owners because of the dual ignition
system and the potential for the silver coil's intermittent operation and thus
the less likelihood of notice by the owner.
Bottom line: In many case it's better to "leave well enough alone".
Last edited by Lorenfb; 07-07-2009 at 12:39 PM.
