TR6 Diagnostics

- Coping with a Poor Idle and Stalling -

[A question arose concerning a rough idle and stalling, notably when the engine revs drop either at speed and in gear or at idle. Below are some answers posted to the Triumphs list.]

--Bad Rubber Fuel Lines--

Date: Thu, 29 Oct 1998 08:40:45 -0500
From: (Bud Rolofson)
Subject: Re:TR6 Keeps Quitting

I had a similar problem until I replaced all the rubber portions of the fuel lines between the carbs and the fuel pump (got the idea from Jim Altman's website). Try it to see if it solves your idle drop problem. Even if it doesn't you've still replaced an old rubber part with a new one which is usually a good idea on these old cars.

I think the rubber loses it's strength over time and may constrict just enough to starve the carbs when not under full pumping pressure from the fuel pump. In any case it seemed to solve my idle drop problem. I'm also going to replace all of the rubber fuel line between the fuel pump and tank just for preventative maintenance.

Bud 71TR6 CC57365

--Clogged Fuel Lines--

From: "Wages, Jeffrey"
Subject: RE: TR6 Keeps Quitting

I had almost the identical problem in my TR6 and after much ado it was....drum roll please.

A clogged fuel line. The metal line running up the car from the tank had more crap in it than I could imagine. Check it out! I replaced mine with a "temporary" run of regular fuel line and it ran great.

Good luck

Jeff
Atlanta-'71 TR6

--Valve Lifters Set Incorrectly--

Date: Wed, 28 Oct 1998 17:35:40 -0500
From: "Mark Hooper"
Subject: Re: TR6 Keeps Quitting

>The other suggestions are all good ones, but I had a similar problem and it
>turned out to be my valve adjustments.
>
>Jim Altman Illegitimi non Carborundum
>http://www.altlaw.com/metro/jaltman.html 69-TR6#CC28754L W4UCK

This sounds reasonable. If the lifters are too tight, then when the motor heats up they will kepp the valves open and the idle will fall. This is a fairly serious thing, since the valve seats will burn quickly if they never fully close. TR6s are clattery beasts; perfectly silent valves indicate an overtight setup. Use the old screw-driver method with the valve cover off the motor. If you don't hear any clacking at all, just a general wearing noise then the lifters are definitely too tight.

Good luck

Mark Hooper

 --Thrust Washers Bad--

From: Sam Haynes

Something not mentioned. If the thrust washers were installed incorrectly, the idle would drop when depressing the clutch.

Sam Haynes

TR3 Original Owner