[TR] TR4A Sputtering (Brian Thomas)

[Brian Induni]

Brian,
I've had the issue MANY times on many different cars, and I would suggest
the follow as a course of action, based on my 40 years restoring British
classics:

1. Replace the points with a Pertronix unit
2. Replace the coil with the correct one for the above
3. Get the best cap and rotor you can, and not the generic kind
4. Adjust the valves to correct specs at the correct temp
5. Check and adjust if necessary the float bowl levels, and consider
changing the float valves. Also adjust the F/A mixture. Use a ColorTune if
you can.
6. Make sure you have a good heat shield in place and the fuel line is
routed to mitigate the possibility of vapor lock
7. Check the timing and set as per the specs. Also make sure the vacuum
advance (or retard if you have that setup as I do in my Stag) is working
properly
8. Make certain the fuel is fresh and not contaminated. If any doubt, drain
and refill the tank
9. Check for obstructions in the fuel line all the way to the carbs. I
disconnect the lines and use compressed air to blow out (no need to 100psi)
and catch whatever comes out. This will give some indication as to what
might be lurking in the system.
10. Take it out right away and test!

I've had this issue caused by one thing one time, and another thing the
next, or a combination of things. It's always best to start off by setting
and adjusting everything as it should be before you set out to correct an
issue.

Remember, there are ONLY 3 things needed: Fuel, air, and ignition! The
trick is getting all 3 to be in the correct proportion and happen at the
correct time!

Sorry for the long winded answer, but I like to be as thorough as possible
to alleviate headaches later.

Brian I


> ------------------------------
>
> Message: 2
> Date: Thu, 14 Aug 2014 20:07:36 +0000
> From: Brian Thomas <thomasb at queensu.ca>
> To: "triumphs at autox.team.net" <triumphs at autox.team.net>
> Subject: [TR] TR4A Sputtering
> Message-ID:
>         <
> C11A4D073AAF8042BECE2B3D862F4EF820A95A9E at MP-DUP-MBX-01.AD.QUEENSU.CA>
> Content-Type: text/plain; charset="us-ascii"
>
> Hi,
>
> I've been fighting a problem with our TR4A for a couple of years and it
> just
> won't go away.  Symptom is a "sputtering" at high-way speeds.  Performance
> seems fine - it just becomes no fun on longer trips.  Our annual fall
> sojourn
> to Stowe is coming up and I'm looking for ideas.  So far:
> *       replaced defective stainless steel muffler that had incomplete
> welds
> on the intake - lifetime warranty honoured by TRF - thanks guys!
> *       fixed problem with coil to distributor wire which was not fully
> "home"
> in distributor resulting in pin making poor contact - checked all other
> plug
> wires at pins - ok
> *       installed NEW plug wires (yellow/black) and distributor cap
> *       perhaps unrelated, but replaced fuel pump that went bad 2 years
> ago in
> Stowe - replacement was Moss reproduction
> Any thoughts?
>
> Cheers,
>
> Brian