TR5/TR250 No spark on TR250

[mcqin]

So I finally freed the engine on my TR250. I posted previously that it sat for 20+ years prior to my buying it. I changed fluids, wires points, plugs, rebuilt carbs and had it running for short bursts. Then it froze up. I was lubing the cylinders and ended up freeing it with a breaker bar. I ran into the previous owner and he suggested that I take off the valve cover gasket and lube the valves, since I was only running for such a short period (seconds) the oil pump probably couldn't get anything on the valves. I did and it freed up immediately. Now the starter spins the engine no problem. You guys had given me suggestions along the way and all helped... thanks!

So now I thought I would be good to go, but no spark. I changed the points again and have checked everything that I can think of. Found a Lucas fault diagnosis manual... ran through that and seems like I should be getting spark. I have not replaced the coil, but from some basic testing, seems ok. Could it just be giving me a too weak spark to see? I haven't had the time to go step by step through everything, but six months ago, I had replaced the plugs, wires, rotor, distributor cap, points and condenser. Like I said, I went ahead and changed the points again, just in case, but nothing. I'm stumped. Should I just get a new coil and try that?

Thanks for any help!
-Bob

 

[poolboy]

Are you getting juice to the coil when the ignition key is twisted to the START position ?

 

[TR3driver]

New parts aren't always good parts; and I can't count how many times I've either screwed up installing the points (the wires go on _before_ the insulator), or forgot to put the rotor back in place.

First thing I'd verify is that the voltage at the points terminal on the coil goes to 12v when the points are open, and to zero when the points are closed. Then I'd try pulling a spark directly off the coil tower (so bypassing the rotor & plug wires). If the primary voltage goes up and down as it should, and no spark at the coil; time to try a new coil IMO. They rarely fail, but it does happen.

 

[mcqin]

I am getting juice to the coil with key in start position. I'll have to check a couple of other things as suggested... thanks

 

[trrdster2000]

Check that stranded ground wire in the distributor plate. They brake under the insulation and nothing works, but all appears OK.

Wayne

 

[poolboy]

I am getting juice to the coil with key in start position. I'll have to check a couple of other things as suggested... thanks

Since you changed some of these components, make sure everything went back like this, paying attention to those insulating washers.

 

[Marvin Gruber]

Distr cap off, rotor button out. Have someone motor engine over while you watch points. You should see spark. If no help to motor engine over, turn sw on and stick flat blade screwdriver inbetween point contacts and wiggle. You should see spark. If no spark, points probably grd some where.

marv

 

[NutmegCT]

Bob - in your first post you mentioned "I changed fluids, wires points, plugs, rebuilt carbs and had it running for short bursts."

So it was firing *before* you removed the valve cover and did that valve lubing.

I'm betting you accidentally knocked a wire loose.

Tom

 

[Tybalt]

Since you changed some of these components, make sure everything went back like this, paying attention to those insulating washers.

I'm with poolboy on this, whenever I hear/see someone say "changed points and no spark" this is the first thing I check.

Check that stranded ground wire in the distributor plate. They brake under the insulation and nothing works, but all appears OK.

Wayne

And since you would have been fiddling around in this area, this is the second thing I check.

 

[dklawson]

I am showing my ignorance. I'd like to ask a general question about the distributor. Based on the pictures posted above, does the TR250 use a Lucas 25 series distributor? I always assumed it would have a Delco like my GT6 but the points configuration shown above looks very "Lucas" like the distributor in my Mini.

 

[TR3driver]

I believe it's actually a Lucas 22D6.

 

[Tybalt]

I am showing my ignorance. I'd like to ask a general question about the distributor. Based on the pictures posted above, does the TR250 use a Lucas 25 series distributor? I always assumed it would have a Delco like my GT6 but the points configuration shown above looks very "Lucas" like the distributor in my Mini.

For some reason known only to Standard/Triumph the GT6 and conventional ignition system Spitfires were fitted with a Delco Remy distributor. As far as I know the Herald and Vitesse, even the Amphicar, had Lucas distributors based on the parts information that I have. Starting in 1975, the Spitfire changed over to a Lucas Opus (?, I believe that was their name for it) electronic ignition system with an internal ignition amplifier.

These turned out to be such problem children due to overheating of the internal amplifier that later production Spitfires (plus MGBs and Midgets) changed over to an electronic ignition system with an external amplifier box and Lucas put out retrofit kits for the 1975 and early 1976 cars that consisted of a new distributor tuned to the advance curve used for that model and production year along with an external amplifier box. Buried somewhere deep in my spares collection is one of these now NLS retrofit kits for Ms. Tybalt's '75 Spitfire.

 

[mcqin]

Got spark! Double checked everything on the points install and still got nothing... went through the Lucas fault diagnosis manual again and it pointed to the rotor arm. Replaced it and it fired up! Thanks for all your advice!

Now that it sparks and fires, I need to keep it running. When I rebuilt the carbs, I'm sure some adjustments are off. Is there a reference to what the base settings should be on the Zenith Stromberg carbs?

 

[mcqin]

I got spark! I tried everything with the points and no luck, but went through the Lucas fault diagnosis manual again. It pointed to the rotor arm... replaced and it fired up!

No that it sparks and fires, I need to keep it running. I'm sure I messed up some settings on the carbs when I rebuilt them. Is there a reference for what the base settings should be on Zenith Stromberg carbs?

 

[poolboy]

The original ZS carbs that came on the 250 did not have adjustable needles for changing the fuel/air mixture, so what all did you fool with on the carbs ?
Tell me and I can suggest what I consider 'baseline' settings.

 

[mcqin]

I followed what was outlined in the buckeye triumph carb rebuild instruction https://www.buckeyetriumphs.org/technical/Carbs/CarbsI/CarbsI.htm. I wanted replace the soft parts and clean the carbs up since the car had not run for about 20 years. I tried not to change any existing settings, but in disassembling and reassembling I assume something isn't exactly the same as when I started. This instruction has you run the engine to get it hot before starting to tune. I never got to run for more than a few seconds, then I had my issue with the engine locking up, which I eventually discovered required the valves being lubed. Once that was sorted, I have had this issue chasing down no spark. So it is now months since I rebuilt the carbs, which I left off on that step.

 

[poolboy]

Then although I might describe some short cuts it would probably be best for you to continue following the Buckeye tutorial.
But since you do not have adjustable needles you can skip that section,
And setting the float levels require removal of the carbs, so consider that.
Setting the Temperature Compensators require their removal.
You can go by the book setting the Throttle Bypass Valve OR just turn the adjustment screw as far Clockwise as it goes then Counterclockwise 11 revolutions.
Next would be the amount of choke that is created.. For that I have my own technique...but use the Buckeye version
Idle speed and synchronization would come next.
Again, my technique differs from Buckeye, so you should follow Buckeye.
Your result is going to greatly depend upon the correctness of your 250 engine's emission plumbing.
Most any of that either not as good as new or if any was disabled or bypassed without proper compensation will cause a less than perfect idle and certain running conditions

 

[mcqin]

Thanks for your advice. The emission plumbing has definitely been an issue, one that I wasn't aware of... The previous owner modified the air cleaner with two small separate units, but the emission hose that connected the air cleaner was gone and nothing attached. When trying start yesterday, I put my thumb over the end of the hose and it ran just fine. First time in 20 years that it ran for more than a few seconds. Seemed to idle just fine. I taped off the hose for now & will put the old air cleaner back on soon. Looks like I can go through and tune the carbs and move on to the many other things that need attention. Thanks again for the advice!