Timing woes

N

nate chase

New member
Apr 26, 1999
553
0
0
Welp, I've come to the conclusion it must be the vacuum advance. I know when
I got it back from Forest City, somehow it had the TVS lines backwards. Also
it was set way retarded (like I'm starting to feel). I guess there was a
method to that madness, not to my liking though... I got that fixed and
reset the timing. Now it pings regardless. I have it so retarded now it
hardly pulls a steep hill and still pings... not acceptable.

I will look close at the vacuum advance and see if it's adjustable (I hope
but would doubt it). Someone mentioned an ACCEL adjustable advance. How much
and do you have a part number or should I just break down and get the
Cinnabar one? Anyone tried to adjust the spring or can you buy weaker
springs to adjust the vacuum advance?

Hate to even call and bring it up to Chuck even though it's a Caspro engine,
distributor, EKE and the whole nine yards.

Nate '75GB (EKE'd out) Omaha
 
Thanks Tom, Bob and Rick for your replies. Got the Summit and Jegs catalogs
right here and have the numbers to order. Hope this does the trick.

Nate '75GB (PO'd about pings) Omaha

>

Date: 8 Jun 2000 04:29:07 -0000
From: tom warner
Subject: Re: GMC: JEGS on line

If you want a JEGS catalog here is the site to go to: http://www.jegs.com/

I would not be without one.

tom
 
Sorry, thanks go out to Emery and anyone else that replied as well! Don't
want to leave anyone out. I'd be lost without you guys! Thanks again to all
of you...

Nate '75GB (Getting to know more about my coach than I ever wanted to...)
Omaha
 
Your problem does not sound like a vacuum advance problem.
Are you sure you are on the # 1 cylinder with the light
when setting the timing? Have you pulled the vacuum line
off the Vacuum advance and plugged it before setting the
timing? Are you sure the knock sensor is OK if it has one?
Are you sure you have not jumped a tooth on the timing
chain. If the distributor has car weights and springs you
would need to put heavier springs on it or it would ping
all the way through the low to mid RPM but I would not
expect a great power loss in this case. If you have had
the Distributor out have you set the engine up correctly
when you reinstalled it? I do not have a part number for
the adjustable Vacuum advance from Accel.

>Date: Wed, 7 Jun 2000 22:05:13 -0500
>From: "Nate Chase"
>Subject: GMC: Timing woes

>Welp, I've come to the conclusion it must be the vacuum
advance. I know when I got it back from Forest City,
somehow it had the TVS lines backwards. Also it was set way
retarded (like I'm starting to feel). I guess there was
a method to that madness, not to my liking though... I got
that fixed and reset the timing. Now it pings regardless. I
have it so retarded now it hardly pulls a steep hill and
still pings... not acceptable. I will look close at the
vacuum advance and see if it's adjustable (I hope but would
doubt it). Someone mentioned an ACCEL adjustable advance.
How much and do you have a part number or should I just
break down and get the Cinnabar one? Anyone tried to adjust
the spring or can you buy weaker springs to adjust the
vacuum advance? Hate to even call and bring it up to Chuck
even though it's a Caspro engine, distributor, EKE and the
whole nine yards.

Nate '75GB (EKE'd out) Omaha

=====
Alan Bredbury
Clinton, Ct.
1974 GMC 26' Classic Motorhome
http://www.finesttool.com/index.html/special.htm

__________________________________________________
Do You Yahoo!?
Yahoo! Photos -- now, 100 FREE prints!
http://photos.yahoo.com
 
Bob,
I tried your ear method this AM but
without sucess. Seems that I can get it
to slowdown on retard but once it speeds
up (as I advance it) it just stays fast
and never drops down as I continue to
advance it like you mentioned. Thought I
could find that sweet spot you talked
about like a bell curve but mine seems
more like a ramp up without any ramp
down. Do you have to back out the idle
screw as it revs up to maintain around
650 RPMs or something to that effect?
Just wondering.
I ordered the Accel adjustable vacuum
advance and the spring/weight setup for
the '74-'79 HEI. I'll try the springs
first. Maybe someone put too light of
springs on the weights and it's
advancing too fast. We'll see.
Everything looks brand new in there (as
you would expect).
Thanks for your advise, though. Always
willing to listen...

Nate '75GB (Good riding weather... 90
today) Omaha



Date: Wed, 7 Jun 2000 23:59:50 -0500
From: "Bob Mclaughlin"
 
Nate,
Thanks for the test. It's always worked for me. Now I have to try it again
to see if I have an overactive imagination. Did you by any chance try it
with timing set at the point it speeds up and see if it pings badly and how
it effects power? I'll let you know how much movement it takes me to hear
the sweet spot (or if I dreamed it).
Bob McLaughlin

- -----Original Message-----
From: owner-gmcmotorhome
[mailto:owner-gmcmotorhome]On Behalf Of chase
Sent: Thursday, June 08, 2000 12:36 PM
To: 'GMC'
Subject: RE: GMC: Timing Woes

Bob,
I tried your ear method this AM but
without sucess. Seems that I can get it
to slowdown on retard but once it speeds
up (as I advance it) it just stays fast
and never drops down as I continue to
advance it like you mentioned. Thought I
could find that sweet spot you talked
about like a bell curve but mine seems
more like a ramp up without any ramp
down. Do you have to back out the idle
screw as it revs up to maintain around
650 RPMs or something to that effect?
Just wondering.
I ordered the Accel adjustable vacuum
advance and the spring/weight setup for
the '74-'79 HEI. I'll try the springs
first. Maybe someone put too light of
springs on the weights and it's
advancing too fast. We'll see.
Everything looks brand new in there (as
you would expect).
Thanks for your advise, though. Always
willing to listen...

Nate '75GB (Good riding weather... 90
today) Omaha



Date: Wed, 7 Jun 2000 23:59:50 -0500
From: "Bob Mclaughlin"
 
You must log in or register to reply here.
GMCMI Fall 2026 Rally
Banner Advertisement for gmcmi.com

Share this page

Share this page
Top Bottom
Back