Ugh! Frustration!!

[mikecyc72usa]

Ok, I posted a bit ago telling how I had no spark at the distributor. Well, I got a good distributor and still no spark. So here's the full story, and maybe someone can pick something I missed.

I got my 78 1500 after it had been sitting since 1993 in a garage. The engine turned, so I was optimistic. When I got to the point of getting it to run, I shot starter fluid in the carbs (I had switched to dual SUs), it ran really strong. So I put in a new gas tank (the original was almost a cheese grater) and fuel system. Things looked to be going well.

Odd part was after I had it started about 5 times, and it'd run for about 10 seconds, it began to get finicky. Sometimes it'd start first try. Sometimes third. Sometimes first try, then not at all the rest of the day. It was getting more and more intermittent. Oddly enough, if I unplugged the wire from the coil to the distributor, I had no spark except when I was shutting off the key, then there was a spark.

I had replaced the cap, plugs, rotor and wires before I even tried to start it. The distributor is the original Lucas 45detc etc one. I then replaced the ignition switch, no luck. I checked all my grounds, no luck. I put in a new coil and Pertronix system. No luck. Tonight I put in a good distributor, still no luck. By no luck I mean ot even a spark.

I've switched starter solenoids, cleaned all the contacts, have a new battery in it, nothing seems to help. I have good voltage everywhere, but it just can't seem to get to the distributor. I've tried bypassing everything, every combination you can think of, still no juice.

So, what have I missed? I'm at the point of considering rewiring the engine. Every electrical system works save the wiper pump motor. My motivation is really low to get my car finished since it doesn't run. I'm at the point of saying why bother with other things I could do since it might be for naught. Any help would be greatly appreciated. Thanks.

 

[Geo Hahn]

I'm not clear whether you're now running a Pertronix or points and (if the latter) whether you are checking for spark at the plugs or at the points.

This is likely something simple that has failed or been missed.

I know this can be frustrating but once it is running you will have learned something and be ready for some fun or the next problem.

 

[mikecyc72usa]

I have Pertronix. I'm checking for spark from the coil to the distributor. It's got to be something simple. This is my 10th Spitfire and 30th Triumph and I've never been stumped like this. Painful. When it's running at least I'll know it has a whole new ignition system, lol!

 

[TonyPanchot]

I ran into a very similar problem and found it to a poor ground
make sure that the coil holder is clean and the bolt the mounting surfaces are tidy as well

 

[AweMan]

It couldn`t be something as simple as a bad key switch, Or could it?

 

[pjsmetana]

I ran into a very similar problem and found it to a poor ground
make sure that the coil holder is clean and the bolt the mounting surfaces are tidy as well

I too have had this exact same problem. The Bad Ground scenario. Made me a big fan of additional grounding points.

 

[71MKIV]

My two bits,

Spark when shutting off the key, means that the key is acting like your points. So there's no switch turning the coil on and off. (points or electronic as in the Pertronix.)

Eliminate the car completely. Test lead from + of battery to + of coil, test lead from - of battery to the case of the coil. BE CAREFUL, read my note below concerning Pertronix systems and power left on. Try to start the engine, no start, the problem is in the ignition system itself.

To troubleshoot the whole system...

Find a helper, test light on the + side of coil, key on, light on? light on dim, you aren't getting full voltage to the coil.
test light on - side of coil, light on? key to "start" light blink on and off?
No blinky's nothings turning the coil on and off.
Test light on the case of the coil, if there is any light at all, run a test lead from the case of the coil to the minus of the battery.

<span style="font-style: italic"><span style="font-weight: bold">Be careful, if your distributor stops in the right place, the Pertronix can burn up in a few minutes with the power on and engine not running. It would be a shame to nuke your new ignition while chasing the no start.</span>
</span>
I have found that new solenoids come through with steel tabs for the connectors, which rust, then don't let electricity through. I've had one or two that started after wiggling the wires on the solenoid.

This could also be a miswired/broken ballast resistor. The 78 has a resistor wire in it IIRC, which can be a tricky trouble shoot. The first test as described above would eliminate the ballast wire.

I don't mean to impune your mechanical skills. I've been at it for over 35 years, and have been working on Spitfires for 25 of those, but I know what it's like to have one bite you in the tail.

 

[Gliderman8]

My suggestion when you have problems (electrical or mechanical) is to STOP and perform DIAGNOSTICS tests similar to what Steve and others are saying. Swapping out parts randomly can only compound the problem and drive you crazy.... it just gets you going in circles. I have found that common sense and logic work wonders.

 

[mikecyc72usa]

I have a friend at Audi here in town and he's the wiring guy. We pulled out the diagram and got his super sensitive tester everywhere. We are finding good voltage all over except non goes to the distributor. He and another friend who is an electrical engineer are both coming over soon to help me sort this out. My second friend has a 78 Spit, too. We'll try the tests again just to make sure. Thanks, and I'll keep you updated.

 

[tdskip]

Hang in there - and good for you in asking for help. Sometime a fresh pair of eyes makes a big difference. Are their any local Triumph clubs near you?

 

[emmett1010]

Could you have the wrong rotor, or cap installed?
If the gap is too great, no spark.
Don't ask me how I know--
Emmett

 

[mikecyc72usa]

I'm a member of Hill Country Triumphs. We're all stumped, but it's time to start from the beginning and work methodically through the car. At least when I do prevail (and I will) I'll knpw that my electrical system will be top drawer.

I do have the correct rotor, etc. It has to be a grounding issue. Time to reclean and check all connections. I'm also suspecting a broken or burnt wire inside a perfectly good looking bit of insulation. Had that on a GT6 once...

 

[tdskip]

Hang in there - and working it methodicaly and taking lots of notes helps. You'll find it.... Keep us posted.

 

[mikecyc72usa]

Well, tomorrow afternoon my buddy the electrical engineer shows up with all kinds of mad scientist gadgets, like an oscilloscope, etc. At the very least, by dinner tomorrow we should know where the problem is and have a plan to rectify it. Update tomorrow evening!

 

[mikecyc72usa]

Well, the testing is done. Bottom line is it looks like the Pertronix unit itself is bad. Everything else tests fine. The oscilloscope showed no pulse while cranking, like no closure. So, time to get another one. Or backdate to points to get it running, but that seems like too much work. My car never had points, just the primitive early Lucas electronic ignition. Once that's done, I'll finish up the braking system, diff, and then hit the interior.

 

[71MKIV]

hmmm, I was afraid of that.

before you go get another one, humor me and double check your inductor/pickup clearance against specs.

BTDT, mumble mumble grumble.

 

[mikecyc72usa]

Yeah, we did that, too. Tested all connections, grounds, coil, wires, everything. When we hooked up the scope and it was flatlined, we knew what we were dealing with. It's the way it goes sometimes. I actually am happy, as the guesswork is finally gone. Now I can rectify this, and finish getting it back on the road. Then I can begin a quest for a TR4...anyone have one that's solid and cheap? LOL