I have had a similar experience this year with my '76. I bought the car late
last year and drove it until October. I rebuilt the carbs, distributor, set
valve clearances, etc. etc. etc. over the last winter, and started driving
on the points ignition with timing set as per Haynes manual. It ran fine
when warmed up, but was pretty rough until the engine temp came up. I have
also checked all the other possibilities like a timing chain tha had jumped
a toot, etc. and they are all correct.
EGR valve is gone, with the head being plugged with a NF bolt, locknut from
the EGR, and 262 loctite. A 1/2" pipe plug and some teflon tape took care
of the intake manifold.
I changed out the ignition to a Crane XR7000, and replaced the coil with a
full voltage type, and the distributor springs at the same time (yes I did
get them in the right orientation), and when I went to set the timing, I had
to get up to about 28 degrees advance to have the car run properly and
accelerate from an idle without stuttering and coughing. I actually went so
far as to "time" the rotor in the distributor by drilling a hole in the cap,
and using the timing light to make sure that the rotor was in the correct
place relative to the contacts in the cap when it is firing.
I finally settled on about 26 degrees advance as being the least I could run
and have the engine perform.
It does perform very well, and has considerably more power with the
electronic ignition that it had on points. I live in a mountainous region
in British Columbia, and the car pulls hills very well even at relatively
low revs with no pinging at all. I run 94 octane gas, and still have the
low compression ratio of 7.5:1. This will likely change this winter as I
need to have the head off to fix an oil consumption problem (guides), so it
will be interesting to see where we end up.
My question to you all is if the car runs well at these settings, what's the
problem? I have put over 6000 miles on the car in some very hard driving
conditions (heat, hills, slalom racing, lead foot, etc) and had no problems
with the advanced timing settings. Is there a potential to do damage that I
am not seeing here?
Thanks
Cris Hemingway
>From: tr6taylor@webtv.net (Sally or Dick Taylor)
>Reply-To: tr6taylor@webtv.net (Sally or Dick Taylor)
>To: jkorsak@heath-bloxom.com (John Korsak)
>CC: 6Pack@autox.team.net
>Subject: Re: Stumble, miss & hesitate
>Date: Thu, 25 Oct 2001 11:26:52 -0700 (PDT)
>
>John---You gave a lot of good information regarding your symptoms. The
>one about getting better mileage when the timing is set at 12 BTDC, but
>idles better when set at 32 BTDC and returns poorer mileage is
>troublesome. Do Frank's suggestion on checking the EGR valve, as it can
>certainly affect idle if stuck in the open position, but a real pain to
>block this off.
>
>You didn't state when this started, and it would be helpful to know when
>this all came about. Did you replace the points with Pertronix when
>'normal' points replacement didn't solve the idle/stumble? How about the
>advance control springs? Either of these two can cause a low rpm
>problem.
>
> What I am going to suggest for your mechanic to check could only
>happen during a rebuild, not during the course of normal wear. See if #6
>valves are "on the rock" (an English expression that took me years to
>figure out) when the timing pulley pointer is exactly on "0" with #1
>firing.
>
>We all like feedback on juicy topics such as yours!
>
>Dick T.
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