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Trouble starting TR7 after short drive

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615joeb Avatar
615joeb Joe Blair
Spring Hill, TN, USA   USA
I’ve noticed from time to time when I drive for a few miles, stop the car, come back after a few minutes my 1980 TR7 has some trouble starting. Eventually it does but wondered if this is common or I should have something looked at. Today’s example was I drove 3 miles to the store, spent 5 minutes inside and came back out and it took a little time to start. Any other time it has no trouble. Starts right up. Thanks for any help!

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mcmahontr7 Chris McMahon
Fort Worth, Texas, USA   USA
Joe,

Is your Tr7 fuel injected?

Chris

615joeb Avatar
615joeb Joe Blair
Spring Hill, TN, USA   USA
Hey Chris
It’s not fuel injected.
Thanks
Joe

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mcmahontr7 Chris McMahon
Fort Worth, Texas, USA   USA
I was checking the fault finding section of the repair manual. The only things I found that it might be are:
Inoperative choke
Choke sticking
Air valve sticking

Does your car have a choke and air valve that you can inspect, clean and test?

Chris

Darth V8R Avatar
Darth V8R Vance Navarrette
Beaverton, Oregon, USA   USA
1980 Triumph TR8 "Wedgie"
In reply to # 1490538 by 615joeb I’ve noticed from time to time when I drive for a few miles, stop the car, come back after a few minutes my 1980 TR7 has some trouble starting. Eventually it does but wondered if this is common or I should have something looked at. Today’s example was I drove 3 miles to the store, spent 5 minutes inside and came back out and it took a little time to start. Any other time it has no trouble. Starts right up. Thanks for any help!

First, you need to check your throttle linkage, to make sure that the linkage is allowing the carb butterflies to fully close, and that the butterflies are syncronized (opening at the same time). I would check your ignition timing too, and pull a couple of spark plugs and take a look at the insulators. They should be the color of corrugated cardboard - a light tan to an nearly white appearance (The TR7s and TR8s are set to run lean from the factory, so frequently the insulators are nearly white). If your plugs are black, then your baseline mixture is too rich, and you should start by getting a carb adjustment tool and leaning the mixture.

If you have a manual choke, you need to make sure that the choke linkage is fully releasing the chokes when the knob is pushed in.

If your car still has the FASD, then you need to see if it is shutting off properly. Start the car, let it warm up, and then place your thumb over the inlet to the FASD. It should not be drawing any air. (The FASD air inlet is the opening inside the air filter housing between the two carburetors).

If it is still drawing air, you should check to make sure that you have a thermostat installed in the cooling system, and that it is AT LEAST 180F, which is 82C. If your thermostat is missing, or it is the wrong temperature (e.g. 160F) then the FASD will never shut off. The temperature is usually stamped right on the thermostat itself.

If your thermostat is correct, and operating properly, but the FASD is staying on, then you probably need to hose the inside of the FASD down with some carb cleaner. They can get gummy and stick. So clean it up and see if that gets it working.

If your FASD is operating correctly and your thermostat is correct, then next I would consider the carb temperature compensators. They are the white covers on the side of the carbs, about the size of your pinky. They are held on by two screws (don't lose them, they are very small). Underneath is a bi-metal strip holding a black plastic pintle, and the smallest nyloc nut you have ever seen. These are not supposed to be adjusted, rather they are supposed to be replaced because they are so boo-hoo-hoo hard to calibrate. Simply stated, you back off the nyloc nut until you just feel the pintle lift off its seat by pushing down lightly with your finger. Then tighten the nyloc nut until you can no longer feel the pintle move when you push gently on it, and then one half turn more to fully seat the pintle. Replace the cover.

Let us know how it turns out.

Vance



1980 Platinum Metallic TR8, navy blue interior
Bare metal respray, Crower cam, raised compression
ported heads, modified Zenith carbs, 0.060" overbore

sheppjr Richard Sheppard
Huntsville, Alabama, USA   USA
Joe, do you have a spacer between the fuel pump and the block? if the spacer is missing and you have a short arm fuel pump, the TR7 can be difficult to start on a hot day.

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