<VV> Bucking / Stalling diagnostics

[Harry Yarnell]

Two things I'd look at first:

Intermittent point wire (assuming you're using point). Copper wire breaks 
internally.
Clogged tank sock or inline filter.

Harry Yarnell
Perryman garage and orphanage
Perryman, MD
hyarnell1 at earthlink.net
----- Original Message ----- 
From: "Doug Mackintosh" <dougmackintosh at yahoo.com>
To: "Virtual Vairs" <virtualvairs at corvair.org>
Sent: Thursday, July 03, 2008 9:23 AM
Subject: <VV> Bucking / Stalling diagnostics


> OK all you diagnostics wizards, I need help!
>
> My daughter's Spyder has an intermittant bucking / stalling problem. This 
> has been going on, but progressively getting worse, over the last few 
> months. In addition to the bucking / stalling it had difficulty revving 
> over 4000 RPM and the tach needle would wiggle and drop when it was 
> bucking. I found a very sloppy distributor bushing and repaired that, 
> which seems to have cured those problems. The car ran like a champ after 
> that for 2-3 days.
>
> But last night we went for a Corvair cruise out on the back roads and 
> after about 30 minutes of spirited driving it started acting up. Here are 
> the symptoms:
>
> - It starts and drives fine for a while
> - It then starts to buck (jerk) intermittantly
> - The bucking increases in frequency and severity
> - It then stalls for a few seconds, then catches again and is OK
> - The stalling recurs, increasing in frequency and lasting longer each 
> time
> - Eventually it stalls long enough that the car coasts to a stop. After 
> waiting a minute, it can be restarted and goes a short distance before it 
> happens again
> - Last night, we stalled at a convenient place and I let it sit a few 
> minutes, then had Leigh crank it while I checked for spark (coil wire held 
> near ground) - nice fat spark (but it may have already cured itself from 
> the resting time). We restarted and drove (at a leisurely pace) about 10 
> minutes back home.
>
> From the behavior I have seen I am suspicious that the problem is heat 
> related since it never stalls until we have been on the road awhile, and 
> it seems to cure itself by sitting briefly, and it seems the longer it 
> sits, the longer it stays "fixed". Also it seems to get progressively 
> worse and more frequent with driving time. The only other possibility I 
> can think of is a partially plugged gas cap vent making it "run out of 
> gas".
>
> I eagerly await your suggestions! When we get to the bottom of it, I will 
> post the results.
>
> Thanks!
>
>
> -- Doug Mackintosh
> Corsa member since 1996
> Corsa/NC member since 1996, Virtual Vairs member
> Corvair owner 1969-1971 and 1996-on
>
>
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