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No spark- trouble shooting electronic ignition

DS
dave silva
Tue, Jun 1, 2021 1:39 PM

Not sure which Electronic ignition i have- it's red, looks like any one of several on Amazon for around $60.

I have no spark. i have power to the distributor.

Looks good inside, no obvious dirt or damage. Unit is seven years old with less than 2000 miles.

Should i just replace it?

Or is there any additional trouble shooting i can do?

--
Dave & Ellen Silva
Hertford, NC

76  Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

Not sure which Electronic ignition i have- it's red, looks like any one of several on Amazon for around $60. I have no spark. i have power to the distributor. Looks good inside, no obvious dirt or damage. Unit is seven years old with less than 2000 miles. Should i just replace it? Or is there any additional trouble shooting i can do? -- Dave & Ellen Silva Hertford, NC 76 Birchaven, 1-ton and other stuff Currently planning the Great american Road Trip Summer 2021 It's gonna take a lot of Adderall to get this thing right.
JR
Jon Roche
Tue, Jun 1, 2021 2:02 PM

This brings back memories from last summer blocking traffic with my gmc 1800 miles from home....

Most should agree on no spark-

Check connector and power to distributor..  you did that.

Next it is usually module.  You can pull that out and auto parts places can test.

Then it could be coil.

7 year old cap and rotor should be replaced anyhow.  It could also be the cap/rotor.  But more unlikely.

Last summer I got towed
To autozone.    I pulled my module out and had them test it and it tested fine.

I then bought a cap, coil and rotor and module.

I installed the old module,  and then installed new cap, rotor and coil.  And it fired up.

When I git home, I bought another distributor.  As I learned that if my module, and coil were not the problem the next item would be the “pick
up”.  I would rather swap out an entire distributor at that point then have to mess with  changing just a pickup coil on the road.    The
distributor also makes a nice storage device for my new module, and now my new coil and rotor.

So I ended up bring towed a mile.  Aaa paid the $300 for that, but ended up loosing a hour or 2 for towing, over less then $100 of
parts(coil,cap,rotor)    And about 15 minutes to swap.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

This brings back memories from last summer blocking traffic with my gmc 1800 miles from home.... Most should agree on no spark- Check connector and power to distributor.. you did that. Next it is usually module. You can pull that out and auto parts places can test. Then it could be coil. 7 year old cap and rotor should be replaced anyhow. It could also be the cap/rotor. But more unlikely. Last summer I got towed To autozone. I pulled my module out and had them test it and it tested fine. I then bought a cap, coil and rotor and module. I installed the old module, and then installed new cap, rotor and coil. And it fired up. When I git home, I bought another distributor. As I learned that if my module, and coil were not the problem the next item would be the “pick up”. I would rather swap out an entire distributor at that point then have to mess with changing just a pickup coil on the road. The distributor also makes a nice storage device for my new module, and now my new coil and rotor. So I ended up bring towed a mile. Aaa paid the $300 for that, but ended up loosing a hour or 2 for towing, over less then $100 of parts(coil,cap,rotor) And about 15 minutes to swap. -- Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
JK
Jim Kanomata
Tue, Jun 1, 2021 2:27 PM

What year is your coach, as 73-74 had the old point and condenser system.
If you have the later with the large cap  with internal coil, We suggest
you change both the coil and the module.
We have found that it is better to get the more expensive module as it
lasts longer.
also get the jell and put it on the bottom of the module for heat transfer.

On Tue, Jun 1, 2021 at 7:04 AM Jon Roche lqqkatjon@gmail.com wrote:

This brings back memories from last summer blocking traffic with my gmc
1800 miles from home....

Most should agree on no spark-

Check connector and power to distributor..  you did that.

Next it is usually module.  You can pull that out and auto parts places
can test.

Then it could be coil.

7 year old cap and rotor should be replaced anyhow.  It could also be the
cap/rotor.  But more unlikely.

Last summer I got towed
To autozone.    I pulled my module out and had them test it and it tested
fine.

I then bought a cap, coil and rotor and module.

I installed the old module,  and then installed new cap, rotor and coil.
And it fired up.

When I git home, I bought another distributor.  As I learned that if my
module, and coil were not the problem the next item would be the “pick
up”.  I would rather swap out an entire distributor at that point then
have to mess with  changing just a pickup coil on the road.    The
distributor also makes a nice storage device for my new module, and now my
new coil and rotor.

So I ended up bring towed a mile.  Aaa paid the $300 for that, but ended
up loosing a hour or 2 for towing, over less then $100 of
parts(coil,cap,rotor)    And about 15 minutes to swap.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/


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--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.gmcrvparts.com
1-800-752-7502

What year is your coach, as 73-74 had the old point and condenser system. If you have the later with the large cap with internal coil, We suggest you change both the coil and the module. We have found that it is better to get the more expensive module as it lasts longer. also get the jell and put it on the bottom of the module for heat transfer. On Tue, Jun 1, 2021 at 7:04 AM Jon Roche <lqqkatjon@gmail.com> wrote: > This brings back memories from last summer blocking traffic with my gmc > 1800 miles from home.... > > Most should agree on no spark- > > Check connector and power to distributor.. you did that. > > Next it is usually module. You can pull that out and auto parts places > can test. > > Then it could be coil. > > 7 year old cap and rotor should be replaced anyhow. It could also be the > cap/rotor. But more unlikely. > > Last summer I got towed > To autozone. I pulled my module out and had them test it and it tested > fine. > > I then bought a cap, coil and rotor and module. > > I installed the old module, and then installed new cap, rotor and coil. > And it fired up. > > When I git home, I bought another distributor. As I learned that if my > module, and coil were not the problem the next item would be the “pick > up”. I would rather swap out an entire distributor at that point then > have to mess with changing just a pickup coil on the road. The > distributor also makes a nice storage device for my new module, and now my > new coil and rotor. > > So I ended up bring towed a mile. Aaa paid the $300 for that, but ended > up loosing a hour or 2 for towing, over less then $100 of > parts(coil,cap,rotor) And about 15 minutes to swap. > > > -- > Jon Roche > 75 palm beach > EBL EFI, manny headers, Micro Level, rebuilt most of coach now. > St. Cloud, MN > http://lqqkatjon.blogspot.com/ > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: > -- Jim Kanomata Applied/GMC, Newark,CA jimk@appliedairfilters.com http://www.gmcrvparts.com 1-800-752-7502
JR
Jon Roche
Tue, Jun 1, 2021 2:40 PM

from his sigfile=  he has a 76 birchhaven,  so should be HEI.    from prior posting's this was a coop restoration probably 7 years ago,  so hence the
red cap.

The heat sync compound is a something for sure to mention.  New Modules come with the compound,  but about enough for one swap.  so if you install a
new module, and keep your old one for spare, you have no heat sink compound.  when I got home I bought some.  (have been known to donate some of my
spare parts to others too).

so now I keep a tube of this handy:
https://www.amazon.com/gp/product/B0044NI2M2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

from his sigfile= he has a 76 birchhaven, so should be HEI. from prior posting's this was a coop restoration probably 7 years ago, so hence the red cap. The heat sync compound is a something for sure to mention. New Modules come with the compound, but about enough for one swap. so if you install a new module, and keep your old one for spare, you have no heat sink compound. when I got home I bought some. (have been known to donate some of my spare parts to others too). so now I keep a tube of this handy: https://www.amazon.com/gp/product/B0044NI2M2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 -- Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/
L
Larry
Tue, Jun 1, 2021 3:37 PM

FWIW, I put a known operating module...that I took out of my distributor....in coach storage, and use the new module. That way I know I have a working
module IF I have a failure. I've seen/heard of to many new modules that were bad right out of the box. JWID

Larry
78 Royale w/500 Caddy
Menomonie, WI.

FWIW, I put a known operating module...that I took out of my distributor....in coach storage, and use the new module. That way I know I have a working module IF I have a failure. I've seen/heard of to many new modules that were bad right out of the box. JWID -- Larry 78 Royale w/500 Caddy Menomonie, WI.
JH
James Hupy
Tue, Jun 1, 2021 3:44 PM

You definitely can turn a good module into junk if you neglect the heat
sink compound between the module back and the plate beneath it. I try to
use the genuine GM product if I can find it. Also, do not forget to provide
a ground path for the distributor.  Dick Paterson includes a lug for that
purpose on his units, some of the other brands do not. It is important.
Jim Hupy
Salem, Oregon

On Tue, Jun 1, 2021, 8:37 AM Larry weidnerl@wwt.net wrote:

FWIW, I put a known operating module...that I took out of my
distributor....in coach storage, and use the new module. That way I know I
have a working
module IF I have a failure. I've seen/heard of to many new modules that
were bad right out of the box. JWID

Larry
78 Royale w/500 Caddy
Menomonie, WI.


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You definitely can turn a good module into junk if you neglect the heat sink compound between the module back and the plate beneath it. I try to use the genuine GM product if I can find it. Also, do not forget to provide a ground path for the distributor. Dick Paterson includes a lug for that purpose on his units, some of the other brands do not. It is important. Jim Hupy Salem, Oregon On Tue, Jun 1, 2021, 8:37 AM Larry <weidnerl@wwt.net> wrote: > FWIW, I put a known operating module...that I took out of my > distributor....in coach storage, and use the new module. That way I know I > have a working > module IF I have a failure. I've seen/heard of to many new modules that > were bad right out of the box. JWID > -- > Larry > 78 Royale w/500 Caddy > Menomonie, WI. > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
DS
dave silva
Tue, Jun 1, 2021 3:57 PM

So, a new HEI distributor should  cover all the bases, right?

Related question, could a distributor/ignition problem mimic a fuel problem?

I drove it 100 miles RT so another member could help me with a transmission swap (ok, i helped him, thanks Tom)

All through the journey  it went from running great to barely running.  Sometimes it resembled a clogged fuel filter  but we ruled that out.

Still, given the history the consensus was that it was fuel related.

I barely made it home with almost no power. this was a couple months ago.  Today was my first attempt to deal with it.

--
Dave & Ellen Silva
Hertford, NC

76  Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.

So, a new HEI distributor should cover all the bases, right? Related question, could a distributor/ignition problem mimic a fuel problem? I drove it 100 miles RT so another member could help me with a transmission swap (ok, i helped him, thanks Tom) All through the journey it went from running great to barely running. Sometimes it resembled a clogged fuel filter but we ruled that out. Still, given the history the consensus was that it was fuel related. I barely made it home with almost no power. this was a couple months ago. Today was my first attempt to deal with it. -- Dave & Ellen Silva Hertford, NC 76 Birchaven, 1-ton and other stuff Currently planning the Great american Road Trip Summer 2021 It's gonna take a lot of Adderall to get this thing right.
KH
Ken Henderson
Tue, Jun 1, 2021 4:26 PM

My take on the ignition situation:  I carry a known good complete
distributor, , ready to R&R the one on the engine.  To me, that's a simpler
repair than replacing the maybe-bad module, especially on my Cad500 where
the distributor is at the front of the engine, not back where it's easy
to get to like on the Olds.

When buying modules, I prefer to get an AC one out of a junked car, being
sure it's got the 7 pins my system required.  I figure the odds are in my
favor that the donor car was NOT junked because of a failed module.  So far
I've won and they've worked when swapped into my running distributor;
that's how I always test them (always using heat sink compound).

On Tue, Jun 1, 2021 at 9:40 AM dave silva admin@oldrv.net wrote:

Not sure which Electronic ignition i have- it's red, looks like any one of
several on Amazon for around $60.

I have no spark. i have power to the distributor.

Looks good inside, no obvious dirt or damage. Unit is seven years old with
less than 2000 miles.

Should i just replace it?

Or is there any additional trouble shooting i can do?

--
Dave & Ellen Silva
Hertford, NC

76  Birchaven, 1-ton and other stuff

Currently planning the Great american Road Trip Summer 2021

It's gonna take a lot of Adderall to get this thing right.


GMCnet mailing list
Unsubscribe or Change List Options:

My take on the ignition situation: I carry a known good complete distributor, , ready to R&R the one on the engine. To me, that's a simpler repair than replacing the maybe-bad module, especially on my Cad500 where the distributor is at the front of the engine, not back where it's easy to get to like on the Olds. When buying modules, I prefer to get an AC one out of a junked car, being sure it's got the 7 pins my system required. I figure the odds are in my favor that the donor car was NOT junked because of a failed module. So far I've won and they've worked when swapped into my running distributor; that's how I always test them (always using heat sink compound). On Tue, Jun 1, 2021 at 9:40 AM dave silva <admin@oldrv.net> wrote: > Not sure which Electronic ignition i have- it's red, looks like any one of > several on Amazon for around $60. > > I have no spark. i have power to the distributor. > > Looks good inside, no obvious dirt or damage. Unit is seven years old with > less than 2000 miles. > > Should i just replace it? > > Or is there any additional trouble shooting i can do? > > > -- > Dave & Ellen Silva > Hertford, NC > > 76 Birchaven, 1-ton and other stuff > > Currently planning the Great american Road Trip Summer 2021 > > It's gonna take a lot of Adderall to get this thing right. > > _______________________________________________ > GMCnet mailing list > Unsubscribe or Change List Options: >
JR
John R. Lebetski
Tue, Jun 1, 2021 5:02 PM

Red?  That’s aftermarket something!  Assuming you mean the cap?  I suggest you diagnose this to be sure it’s not fuel issue.  Ign modules
usually are either good or bad. I say usually because heat related issues can come up. Do not test for spark by disconnecting a plug wire!  This sends
coil to max voltage rise and stresses the module with back EMF. Get a spark tester at auto parts store instead. Other HEI things to look for are coil
ground wire, cracked rotor, bad contact button, fatigued pickup coil leads.

John Lebetski
Woodstock, IL
77 Eleganza II

Red? That’s aftermarket something! Assuming you mean the cap? I suggest you diagnose this to be sure it’s not fuel issue. Ign modules usually are either good or bad. I say usually because heat related issues can come up. Do not test for spark by disconnecting a plug wire! This sends coil to max voltage rise and stresses the module with back EMF. Get a spark tester at auto parts store instead. Other HEI things to look for are coil ground wire, cracked rotor, bad contact button, fatigued pickup coil leads. -- John Lebetski Woodstock, IL 77 Eleganza II
JR
Jon Roche
Tue, Jun 1, 2021 5:19 PM

I prefer to use a timing light to check for spark.  It is very quick to hook up.  zip tie the trigger on and if you have proper spark it will flash
pretty consistently, and easy to read.  if you hook it up carefully you can run down the road with it and get an indication on the spark when a
problem shows up.

an entire distributor generally will take care of spark problems,  but you are swapping too many parts at once, and may end up chasing problems.  I
can change a distributor module quickly.  a coil is not difficult at all.  but the pickup in the distributor means taking the distributor apart, so
that is why I keep a spare distributor.  I would not want to mess with pulling a distributor out unless needed on the olds powered GMC.    The pickup
is one of the more rare ignition failures.

yes-  fuel problems can mimic ignition problems.  and vice versa.  No spark is no spark.  and no gas is no gas.  whole different deal when you are
dealing with intermittent problems.

--
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/

I prefer to use a timing light to check for spark. It is very quick to hook up. zip tie the trigger on and if you have proper spark it will flash pretty consistently, and easy to read. if you hook it up carefully you can run down the road with it and get an indication on the spark when a problem shows up. an entire distributor generally will take care of spark problems, but you are swapping too many parts at once, and may end up chasing problems. I can change a distributor module quickly. a coil is not difficult at all. but the pickup in the distributor means taking the distributor apart, so that is why I keep a spare distributor. I would not want to mess with pulling a distributor out unless needed on the olds powered GMC. The pickup is one of the more rare ignition failures. yes- fuel problems can mimic ignition problems. and vice versa. No spark is no spark. and no gas is no gas. whole different deal when you are dealing with intermittent problems. -- Jon Roche 75 palm beach EBL EFI, manny headers, Micro Level, rebuilt most of coach now. St. Cloud, MN http://lqqkatjon.blogspot.com/