Does it have an EGR valve. If so, remove it and plug the hole and see if
any improvement. It's any easy check before you get more in depth with
your troubleshooting. Can cause many symptoms. Won't affect timing but
can affect idle and lower RPM performance.
Good luck,
Jay Welch, Abington MA
1971 TR6 project
1973 TR6 driver - wanting to "Drive it Hard"
Member "Cape Cod British Car Club" @
http://clubs.hemmings.com/capecodbritish/
On Thu, 25 Oct 2001 09:40:17 -0500 "John Korsak"
<jkorsak@heath-bloxom.com> writes:
> Dear 6 Packers,
>
> I have a problem that my mechanic and I can't solve. I have a 74
> TR6 with
> overdrive that runs good. The problem is that my timing needs to be
> set at
> 32 deg BTDC at idle to run smooth (yes, I said 32). Setting it at
> 12 deg
> BTDC at idle makes it stumble, miss and hesitate between 1500 RPM
> and 3000
> RPM. After 3000 RPM it runs fine. Vacuum retard does not seem to
> be
> working as it has no effect on timing while on or off (I don't think
> that
> thermostatic vacuum control switch is working. It has vacuum from
> carb, but
> not at distributor).
>
> I have replaced points with Pertronix system, replaced spark plug
> wires,
> fuel filter, carb diaphrams, dash pot oil (10W50,stays full), and
> distributor springs. I have adjusted carbs full rich, but engine
> does not
> increase RPM when I lift Air Piston 1/16". I just finished checking
> compression, and her are my readings: (stock head &
> cam)130,125,140,125,125,140. We also checked to see that #1 piston
> was top
> dead center with crank shaft indicator. Tach cable points slightly
> away
> from being parallel with engine block (just outside of fuel pump).
>
> I also just checked my gas mileage. A 200 mile trip this last
> weekend
> resulted in only 22 MPG while I got 28 MPG when I went to the Trials
> (with
> timing set at 12 deg BTDC). The TR has always started great hot or
> cold(with
> choke).
>
> Any suggestions?
>
> John in Kansas CF25165UO
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