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TR2/3/3A No Spark on the TR3

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sammyb

Luke Skywalker
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Well I've been tinkering with the project TR3 and I have no spark. Changed the coil to one I know that works, and still have no spark -- and appears no power to the coil.

Drat!

I'm looking at the wiring diagram, and now I have to trace back. It looks like there can only be a few things, though.

Anyone been down this road before and care to save me some time? I'm guessing there's a wire off somewhere.

And yes, the car cranks -- very nicely, at that. I installed a new high-torque starter.

Interestingly, somewhere along the line I gained my turn signals, but I lost the left headlight! (The wires came undone, because I found them totally undone.)

Sam
 
Recrimped the white wire to the coil -- I have spark there now, but still nothing to from the dizzy.

I'm going to make sure the plug/wire from the coil to the distributor is actually fully engaged in the cap (there's some black electricians tape on it.) Then I'll make sure the points/condensor etc... are all appropriately setup. I changed them when I first got the car, but maybe I did something stupid. (It wouldn't be the first time.)
 
Did you change the points and condenser? If you did, I would look there....

Don
 
I did, but there was no spark before, as I remember...I think that's why I changed the points to begin with.
 
Check the wire inside the dist that grounds the contact plate to the distributor housing at one of the plate mounting screws. You can put a new jumper wire in place of the one that's crimped to the dist plate, just run it under the condensor mounting screw to the plate mounting screw. PeterK
 
Does your dizzy use the points with the separate little plastic insulator bits that must be fitted to the screw/stud where the condenser attaches? With the later 25D4 dizzy I've seen a number of problems where these washers weren't put in correctly or the forked lug on the condenser was positioned wrong... both of which can effectively ground the moving arm of the points. This is like having a permanently closed kill switch.
 
Lots of possibilities, I'll add... that White/Black wire that connects the coil to the distributor seems prone to internal breakage that isn't evident under visual inspection. May be intermittent so if you test it with a ohmmeter wiggle it about a bit by both ends to be sure of continuity.
 
Check your rotor I have had a couple rotor crack and short to the distributor and put me on the side of the road.

Don
 
Points, condensor, rotor, connecting wires, coil -- all are potential failures. The good news is that you can literally hold the entire ignition system in one hand...

MVC-759F.JPG


and an eBay bottom-feeder can put a spare one together for about 40 bucks. Greatly simplifies problem diagnosis and roadside repair. I know I carry too many parts in the boot for most folks' taste, but this is something I never leave home without.
 
That is great, Geo!!!

Basil, I think Geo's pic has to go into the BCF Hall of Fame (should it ever be created.)

I'm guessing that one of the wire connections was faulty AND I put the points in wrong. I'll check inside the dizzy tomorrow and report on what I find (or shall I say: "the dumb thing Sam did installing the points")
 
Did you forget to put the little plastic insulating washer in the right place when you put in the points? It took me three days to figure that one out when I did it. It sounded just like your situation; spark all the way up the line to the dist. and then nothing. Grounding the points out will do that to you.

Dick
 
Dick gets three gold stars!!!

When I installed the points, I was so concerned with everthing else on the car, I didn't even notice some part of the plastic washer was all-out missing!

I just switched to a new points set, and tested ...still no spark, then after testing with the test light, head scratching...DUMMY -- the cap retaining lever was laying on the end of the wire from the coil.

Cleared that and ZAP!!!

We're sparking.

So I think as soon as my dad gets here (he's visiting the grandkids here today,) I'll fire her up for the first time. I bought the car for him anyway.

Cheers everyone!!!
Sam
 
Great news! Even when it's our own fault it's still always nice to figure out the mystery when these old beasts don't decide to work right.
 
Er, um, I mentioned the plastic washers also.

Glad you got it sorted out.
 
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