Hi,
Are you 100% sure that you don't have a fuel problem?....fixing everything
else may have helped overall performance but not made the original issue go
away?
I guess you've got 2 carbs and wonder if the second one is getting enough
gas when it all heats up down there. Maybe the pipe to the second carb is a
bit grotty inside. Do you have those little mesh filters in the banjos? They
get blocked up.
Do you have an inline fuel filter in that area? I did and had all sorts of
problems until I took it out. I never knew how it was causing trouble - on
acceleration and load, particularly on steep hills - but it was and removing
it made a huge difference.
What is the heat shield like? I don't know much about BJ8 heat issues, but I
know that they can be major other Mks.
Simon.
-----Original Message-----
From: owner-healeys@autox.team.net [mailto:owner-healeys@autox.team.net] On
Behalf Of pdeturck@rochester.rr.com
Sent: 28 June 2005 02:56
To: healeys@autox.team.net
Subject: high rpm - misfire - followup
Listers -
A few weeks ago I posted about my 66 BJ8 running rough
at high (3500+) rpm. I have followed the suggestions of this
illustrious and knowledgeable list and things are noticeably
better but the problem now is more specific.
Here's what has transpired so far. What I thought originally was a
bad coil --- was in fact a coil failing. The replacement coil (high output
type) made a big difference.
New parts
========
coil
pertronix ignitor
ignition wires
distributor cap
plugs
damper oil at 20W and present
vacuum advance checks out OK
dynamic timing set
both HD8 carbs rebuilt
With this configuration, when I first go out for a drive,
the BJ8 performs wonderfully. There is only the hint of
a stumble at about 4000+ rpm.
But drive it for while, get it up to temperature and it stumbles
worse and worse until it almost seems to have a rev limiter at 3000 rpm.
You can slowly get the rpms up and cruise along fine but any sort of
moderate or hard accelleration (load) is cause for what sounds like half
the cylinders missing. Back off and it cruises just fine.
Plugs 1, 2 and 3 are slightly rich looking compared to 4,5 and 6 but all
in all, pertty clean.
Could I have a distributor problem that is accentuated by heat?
If so, any suggestions on a remedy?
Any thoughts on other causes?
I have swapped most of the components listed above with other parts
including a different pertronix ignitor. With exception of the old coil
(which
really runs poorly all the time), nothing seems to change the condition
when hot.
Could I have a new coil that's bothered by temperature?
TIA.
-pd-
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