<VV> Help - Convention Attendance at Risk!

[Ken Pepke]

How frustrating!  You sure have touched everything!  I have experienced a very similar situation and, although it tested well, the coil was the problem.  Perhaps you should take a moment to be sure the coil is not installed backwards.  And, if you can, swap a coil from a known to be running well engine for a test.  Hope you have good luck with this.

Ken P
Wyandotte, MI
Worry looks around; Sorry looks back, Faith looks up.

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On Jul 11, 2012, at 7:55 AM, Jeffrey B. Aronson wrote:

> Sorry in advance for this long email, also a post on the Corvair 
> Center/Corvair Forum!
> 
> I'm having a long stretch of continued running problems with my '66 
> Monza 110/4; now it's making my attendance at the Convention questionable.
> 
> The core symptoms are that the car will start and run quite well for 
> approximately 15 minutes - nice idle, smooth acceleration, good power - 
> and then cease to accelerate. Pressing the throttle to the floor will 
> result in a tremendous "bogging."
> 
> The only way to pick up and hold speed is to feather the accelerator to 
> slowly build speed. The car doesn't just slow down, it wants to die off 
> the side of the road. Unless the car sits for a few hours it will not 
> run well again. It will tootle about town fine - it only manifests 
> itself when it's under load at speed. When it has died, it will sputter 
> to a stop. Then it will start again. A mechanic on the roadside has seen 
> the carbs shoot gas when punching the accelerator - so have I.
> 
> The car has 129,000 miles on it. I've had the car since 2007 and have 
> put about 15,000 miles on it since its purchase. It did not exhibit 
> these symptoms until the past year.
> 
> A leak-down test yesterday revealed no cylinder blowby in any cylinder. 
> All the plugs looked the same - dry and a bit black from running around 
> town too often - both to me and more experienced Corvair enthusiasts 
> [thank you Dirigo Corvairs].
> 
> I've tried to tackle this in sequence to diagnose the problem 
> effectively, to determine whether the problem is fuel or spark, or some 
> combination of the two. Here's what's been replaced [so far to no avail]:
> 
> -New spark plug/coil wire set [Clarks]
> -New coil [Clarks]
> -Rebuilt distributor [Clarks]
> -New points, cap, rotor, condenser (replaced twice) [Clarks]
> -New engine wiring harness [Clarks]
> -Rebuilt carbs [Clarks]
> -New fuel lines from sending unit to carbs
> -New filter sock
> -In line fuel filter
> -New fuel lines in engine compartment
> -Replaced Facet electric fuel pump twice, then removed the pump altogether
> -Replaced mechanical fuel pump twice, now running only on mechanical pump
> -Gas tank drained examined with scope and pronounced clean
> -Filter stones completely clean
> -Carbs balanced and synchronized by an experienced tuner and confirmed 
> by a Unisyn.
> -Exhaust "doors" open when the car is warmed up
> -Placing my hand over each carb throat when running results in the same 
> drop in rpm.
> -Running the car at speed without a gas cap does not change the running 
> problems.
> -Balance tubes, vacuum hose and PCV pipe are fine and the PCV pipe has a 
> tiny orifice at the vacuum hose end. It runs the same with and without 
> that orifice.
> 
> Since the car starts and fires I can confirm that I have spark, low 
> tension and high tension. On the side of the road the car will restart. 
> Cracking a fuel line at the carb shows that I do have fuel pressure in 
> the lines.
> 
> The coil is in the stock location and has been there since I purchased 
> the car. The coil's been replaced twice with no change in running 
> condition. The coil was hot to the touch yesterday when I experienced 
> the problem again - but it's always been hot after running. When last 
> tested it had the correct voltage when running.
> 
> The car does run around town without these symptoms - the problems seem 
> to be when the car is running warm [> 10 minutes] and under highway 
> speed load.
> 
> The car needs to earn its keep as a work vehicle [4 hours of driving 
> once a week] and I want to keep my reservation and registration at the 
> Convention. Has anyone else experienced this problem and discovered a 
> solution not on my list?
> 
> Thanks for your advice,
> 
> Jeff Aronson
> Vinalhaven, ME 04863
> www.landroverwriter.com