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TR6 TR6 rough running - what can it be?

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tr6web

tr6web

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I can't for the life of me figure out this issue.

Engine starts right up and runs, lots of power, but it is missing at any speed. I've tried turning/retarding the distributor (which has all new points, rotor, condenser... also got a new Lucas Sports Coil), and checking for vacuum leaks using starter/carb cleaner (no leaks I can find, engine doesn't respond to the carb cleaner anywhere I spray it). Carbs have new seals too, but I didn't check to confirm nothing happened since they were put in last year.

Is it timing? If so, can someone explain in laymen's terms how to check? If not, what else can I try? Thanks everyone.
 
Were any of the new parts put on the car before or after the problem started?
Charley
 
Carbs have new seals ?
What exactly are you referring to and what was removed or disassembled in order to do whatever was done ?
 
Basics. Do a compression test, inspect plugs. If all six pots are good, use an inductive timing light and check all six wires, one-at-a-time for HV current.

Those two procedures should reveal which hole is misfiring. Once that's known the fix can be determined. Otherwise it's just guessing.
 
You may not have the inductive timing light Doc mentions. A fair shade tree test is to pull each wire off its spark plug, one at a time, and see which one doesn't make it run worse. That will probably be the cylinder in question. If this test doesn't worsen the running at all, at least you will know where the problem is not. Keep us posted.
Bob
 
poolboy said:
Carbs have new seals ?
What exactly are you referring to and what was removed or disassembled in order to do whatever was done ?
Click to expand...
Carbs have new seals as of early 2021. British shop added new kit. She was running fine for many months and just quit. Replaced all of the points, condensor, rotor, cap and coil and finally started up. Just can't figure out why it's missing.
 
Another source of irregular and hard to diagnose misses is the condenser. Brand new condensers do sometimes come with faults. If you still have your old condenser, you might try putting it back in there. You might try the same with the rest of your old ignition parts, one by one.
Bob
 
The important part of my question was. Were these parts added before or after the problem started?
Charley
 
tr6web said:
...She was running fine for many months and just quit.
Click to expand...
There's your clue. What would do that? Bad ignition capacitor, vacuum leak, fouled plug, burned valve...

Start by thinking it out and troubleshoot it methodically. Randomly replacing parts is probably the least efficient way to fix a problem.
 
Sarastro said:
There's your clue. What would do that? Bad ignition capacitor, vacuum leak, fouled plug, burned valve...

Start by thinking it out and troubleshoot it methodically. Randomly replacing parts is probably the least efficient way to fix a problem.
Click to expand...
Hi Sarastro. I was just explaining what I replaced. I did it all one at a time to see if I could figure it out. It started up after I replaced the condensor.
 
The point of Charley's questions is that, if a problem starts soon after (especially immediately after) you have worked on the engine, something you did is the problem. The idea is not to blame you, but to give you a starting point for diagnostics. Regardless of any of that, and even if the problem started without any prior work to be questioned, your diagnostic steps as suggested by several of the responses would still be the way to figure it out. The fact that the car started up after the work does not rule out that the work or parts are not the cause of poor running that arose after the work was done.
Bob
 
It could be the camshaft. that is what I went through when my cam shaft had lost a lobe. If you are still have trouble, I would pull the valve cover and watch the springs to make sure the springs have a full travel when adjusting because when a lobe fails, you can still adjust the valve thinking you have done that adjustment correct because the spring will always be closed ready for adjustment when the lobe is gone.

steve
 
Figured it out and it was one of those dumb ones. The painted labels on the the #5 and #6 distributor wires had rubbed off and they were mixed up when I put them back. Running like a champ now!
 
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