• Hi Guest! Being a Paying Supporter is NOT a requirement to participate at BCF. However, subscribing will help ensure we can continue to serve the LBC community for years to come. If you enjoy BCF and find our forum a useful resource...Please consider supporting us by **Upgrading**
    (PS: Subscribers don't see this banner)
Tips
Tips

TR6 Inertia cut out [off] switch TR6

jobster

Senior Member
Offline
OK, went thru my first experience with my new TR6 not wanting to start. Turning the key everything worked, motor turned, no start. Again and again, and than realised I did not hear the fuel pump. DPO had installed an ingenious anti-theft system under the driver seat cutting the electricity to the fuel pump. Messed around with it, nothing. In the end it turned out to be a malfuntioning inertia cut out (or cut off) switch. Took it out, hotwired the cables and off we go. At home, took it apart (very easy) cleaned the rods, bend them into shape, installed it and like new.
As long long as the square magnet or the steel ball is not missing (unlikely, unless the whole casing went to pieces which si also unlikely to happen), this very hard to find item can ben easily made to work again.
 

TR3driver

Great Pumpkin - R.I.P
Offline
DNK said:
Which inertia switch was it?
The one only found on fuel-injected TR6 (meaning non-US-spec). Don't recall the TR6 location offhand, but on the Stag it's mounted to the firewall near the fuse block.
 

TR3driver

Great Pumpkin - R.I.P
Offline
DNK said:
OH, it's your Stag. Thought it was a 6
Er, no, sorry for the confusion. I wasn't the original poster, just (perhaps rudely ?) trying to answer the question. Jobster (the OP) was talking about his (fuel-injected) TR6.
 

piman

Darth Vader
Offline
Hello all,

I don't think the Stag had an inertia switch, just the TR5, TR6 (injection) and the 2.5 P.I. saloons. This was to cut the fuel pump in case of an accident due to the 100+ p.s.i. fuel pressure which if a line was cut would be rather nasty.

Alec
 

tomshobby

Yoda
Offline
Would a wire to the ignition lead on the starter and another to the 3rd post on the oil send unit (anti-run-on valve lead) work?

The starter lead would make it run when the starter is engaged and the oil send post should get it to run when there is oil pressure. The starter lead would need a diode to prevent feedback so the starter would not run when there was oil pressure.
 
OP
J

jobster

Senior Member
Offline
It's the inertia switch to cut off the fuel pump in case of any mishap. You could do it manually as well if for any reason you need to switch on the ignition and don't want to have the fuelpump run in vain. It's mounted, at least on the TR6 PI versions, behind the main brake cilinder on the firewall.
 

TR3driver

Great Pumpkin - R.I.P
Offline
tomshobby said:
Would a wire to the ignition lead on the starter and another to the 3rd post on the oil send unit (anti-run-on valve lead) work?
Several problems with that approach, not least of which is that PI TR6 don't have the 3-post oil pressure switch.

Bosch actually made a cute pump-control relay, that monitored the ignition and shut the pump off if the engine wasn't turning. But I doubt it's any more reliable than the Lucas inertia switch (which seems to frequently show up used on flea-bay).
 

DNK

Great Pumpkin
Country flag
Online
I have a ford style on my car,yet unproven, has some kind of a switch that cuts power on jolts and such.
 
Similar threads
Thread starter Title Forum Replies Date
G Inertia Cut-Off Switch - E-Fuel Pump to Ignition [Key] Switch Austin Healey 3
Lin Gear Reduction High-Torque Starters: Inertia or Pre-engaged? Austin Healey 4
Gliderman8 TR6 Inertia switch location Triumph 9
Gliderman8 TR6 Inertia switch mounting location Triumph 4
steveg Fuel pump inertia cutoff switch Austin Healey 33
Got_All_4 TR2/3/3A Suggestions for shoulder harness retractable/inertia seat belts Triumph 4
GTP1960 TR2/3/3A Fuel pump inertia switch vs. dead engine switch? Triumph 14
H TR2/3/3A SECURON INERTIA SEATBELT ON TR3A Triumph 5
B T-Series Fuel pump inertia switch? MG 4
glemon T-Series MGB Inertia Switch MG 13
B Inertia, Ennui Triumph 30
Z T-Series Inertia fuel cutoff switch MG 7
Z Fuel inertia switch Austin Healey 3
Daimlerdb18 How to overcome restoration inertia MG 30
M TR6 TR6 inertia seat belts Triumph 8
A Inertia Switch Spridgets 1
B inertia reel seat belts Austin Healey 1
Rut Cut down windshield Spridgets 22
BN6 BJ8 Outrigger Cut Out For Exhaust Austin Healey 3
G General Tech Have new blank key for TR3 but cannot get it "cut" to fit ignition. Triumph 14
KVH TR4/4A Should I Cut the Lower Windshield Gasket Triumph 2
D You Tube made me do it. I bought a Milwaukee dry cut saw. Restoration & Tools 6
69MGC MGC Cut out the Rust! MG 9
Drone Dog cut-off switch Austin Healey 20
W TR2/3/3A Why a PO cut these holes in rear floor? Also, question re dealing with captive nuts Triumph 6
K TR2/3/3A A cut down side curtain for Fall driving? Triumph 7
CJD TR2/3/3A Cut away TR3 Triumph 6
Boink Moss Healey Cut-out... I'll ask... Austin Healey 2
Boink Cut-away B series engine... MG 6
TLW1958 TR6 1972 TR6 No ignition cut off Triumph 2
BobMunch MGB The MGB Cut-away, Heritage Motor Centre Museum MG 11
J Windshield question pt.2: Why not cut the frame? Spridgets 9
Boink Battery cut-off switch options... or??? Spridgets 10
K TR2/3/3A TR3 Cut Off Side Curtain. Triumph 18
D battery cut off switch Austin Healey 29
T TR4/4A TR4a positive earth to negative cut over? Triumph 9
Tinkerman Battery cut-off switch installation Triumph 22
AUSMHLY fuel cut off Austin Healey 23
vping T-Series Adding a battery cut off switch. MG 16
G To cut or not to cut Austin Healey 3
V Intermittent engine cut out 1989 v12 xjs Jaguar 9
Ouagabambou Cut, torn steering inner tube [+ photograph] Austin Healey 22
T TR6 What year TR6 cut over to Type-J O/D? Triumph 3
roofman Looks like Dale made the cut! Triumph 13
B T-Series cut off switch in MGB? MG 7
T What year cut-over to the 1500? Spridgets 13
jmwuva05 Fuel pump cut off switch Spridgets 6
R Cut off switch wire Austin Healey 2
jlaird First cut on trophies for Lake of the Ozarks Spridgets 32
beaulieu fixing a cut in half Temperature capillary gauge Restoration & Tools 13

Similar threads

Top