Well, this is a new one on me. I just got back from the alignment shop because they could not drive my car off the rack. Mainly this was because it would not start! The motor turns and turns, you can smell that it is getting plenty of fuel, but no ignition. The odd thing is that all accessories are working-wipers, turn signals and lights except for the aftermarket gauges installed under the dash. All the fuses are good, battery connections/ grounds are tight and the motor cranks easily. graemlins/clonk.gif

We fooled with the wiring for a while to no avail. My dash harness is a rat's nest of splices, electrical tape, crimp connectors and capped wires not to mention being "rigged" at the ignition switch (factory plug cut off and new ends put on each individual wire). Since it was closing time we left the car on the rack and locked the place up. There is a standing appointment for a flatbed tow rig to drag it home to me in the morning.

Any suggestions on where to start? I currently run a Mallory Promaster coil and unilite distributor- any common failures on these to speak of? Troubleshooting? I was already planning on replacing the dash harness (before Vintage air goes in). Maybe I should bite the bullet and replace it now instead of tracking down shorts through all this mess?! :confused:

Sometimes you may dive to deep on something that's simple. Do you know for a fact that it's getting spark? It's easy to look into the carb and see the fuel getting pumped when you crank and depress the accelerator pedal. I'd pull the coil wire off and put the wire so close enough to your block and crank it to see if the is spark arching. Check cap and rotor make sure there good. do a spark test on each plug wire if you have to. Just make sure you have spark and it's getting gas. After that, things could get deeper.

couple things - all by my past blunders.
Check: the coil wires and tach if you have one. Make shure you dont have them crossed, younever know!
Check the wire leading from the starter.
check the wire that leads from the battery to ignition.
The easy check, as said before, is to see if you got spark.
If no spark it may be the pick up modial in the dist.
Like I said, I made my share of blunders and hope they will help someone!

I'm not sure if you know how to hotwire a car but hotwire it. If it starts you'll know the problem is under the dash. Also maybe check to see if the distributor is turning when you are cranking.
Since it cranks just positive to coil then crank.
Nice car.

Very nice car !! No radio antenna? Could be one of two attitudes: A total gearhead, no radio and rolls the window down to listen the pipes, or 2. A thumper, has a CD player and thumps his head to the music..........LOL Sorry to read of your bad luck. Air, fuel and spark. All happen at the right time, you've got something....... graemlins/thumbsup.gif ;) :D

So far I haven't tried much besides wiggling a few wires, checking fuses and scratching my head. Unfortunately the alignment shop did not have much in the way of spare wire laying around so we tried to jump a hot lead to the coil with a test light- no difference. I didn't think about pulling a spark plug boot to see if there is any fire at all, graemlins/clonk.gif but it is obvious that something is amiss in the ignition circuit somewhere for whatever reason.

I'll dig into it this wekend for sure. Fortunately Dnult lives just on the other side of town from me and has offered to help track down this problem. I hope it is something simple...

As others have said, could be distributor at fault. If orig points dist, rubbing block on point set may have worn down, points not opening up.

Choptop,

I've not had much experience with the Mallory brand of distributors but in a recent conversation with a fellow gearhead he suggested that he reuse one he has for his current project. I suggested that he contact our local speed guy's and inquire what they thought? Our local speed shop's reply.... The owner indicated that there's a module in the distributor that is prone to failure and indicated that he sells many of these for that very reason. "Once they pop you're done" also there rather pricy I understand. Don't know how much help this is, but I thought that I would share in hopes to find a solution


Best of luck,
Tom

Where exactly did they spray around wiring. Maybe the paint got between the connections enough to make trouble. That or an alarms kill switch, old kill switch or just the alarms automatic kill (carjack) till reset needs to be done. I was in traffic a long long time ago checking my engine under the hood seeing I wasn't getting gas then figured I might as well relax a little and get back in and flip the rear fuel pump switch on that feeds the front fuel pump. :D

Tom, that is an interesting point you have made. I wonder if leaving the ignition on (the guy told me it was left on the entire time they aligned the car, ~3 hours <why they did this I don't know>) could have overloaded some of the components in either the distributor or the coil? Unfortunately I have zero experience with the Mallory system on my car. It was there before I bought the car and has worked flawlessly up to this point (3+ years at least).

I guess I'll know more when I get the multimeter after it...

Scott, Please get me more info on the distributor like model number ect. I need to make a trip to the speed shop tomorrow and can inquire more on the issue that the owner told me about several weeks ago. Hopefully I can then give a better suggestion on how to repair the beast


Thank,
Tom

the unilite module is very prone to failure. it's real sensitive to voltage spikes and such, thats why they (mallory) tells you to use the correct ballast resistor with the distrubutor. definately check for spark at the plugs, if no spark check for voltage at the dist feed wire, if theres voltage present, you can almost bet its the unilite module. do you have a spare dist. you could throw in? that might save you the 100$ a new module will cost you to find out for sure. good luck with it

Tom,
If you get this in time the unilite part # is 4748201. There is another # below that that is D 70 something (can't see the figure due to the angle- it's on the rear of the dist.)

68rs406, thanks for the info on the module also. I suspect this is what may be wrong, but I'll find out for sure this weekend when I have more time to dig into the problem. What does the ballast resistor look like? Is it a ceramic block with studs on one side for the power connections? I don't see any other obvious components anywhere.

Any recommendations for a more reliable system or are all the pointless systems vulnerable like the Mallory? I have firewall clearance issues (which is why there is a Mallory unilite there to begin with) so it would have to be a small footprint distributor.

Scott,

Got the info and will check with my speed guy today! I do know that he recommended the MSD distributor to my friend that was inquiring about reusing his Mallory piece. As a matter of fact I know he bought the suggested MSD piece. I will see which one he suggests for a tight fit as a replacment to the Mallory and a cost for the replacement module.

Regards,
Tom

I have the MSD Ready to Run dist. in my '67 and it clears the firewall just fine. Three wire hook up and away you go. It's been solid for me. No fancy box just the dist. and a coil. The only down side is it does not have an adjustable vacuum adv. on it.

choptop, glad i could help, hope you get it figured out. yes thats the ballast resistor you described, the ceramic block. if you have voltage at the resistor, and no spark, you can almost bet its the module. it should be 12v on the ign. side of the block (input), and i believe around 8v or 9v on the distrubutor side(output). as for other options, i went with a msd pro billet, its just a magnetic pickup in the dist., nothing really to fail. but you need a msd box to go with it. this works ideal for me and my application, but it may be more than you need. the msd ready to run might be a good choice. good luck, hope you get it figured out soon! by the way, sweet car! graemlins/thumbsup.gif

Thanks to Dnult's help we tracked down what we think the problem is. We pulled apart the ignition switch, fuse block and engine harness connectors to test continutiy along the ignition circuit.

Turns out that the hot feed to the coil at the firewall was very loose (read hacked by previous owner/s) and the spade was not making proper connection to the rest of the circuit. We jumped the suspected bad portion of the cicuit and the motor kicked right over. Of course it promptly backfired through the carb and scared the crap out of us both!

Big thanks to Dnult for taking time out of his 4th of July to help me with this problem. I owe you one! graemlins/beers.gif

Now all I have to do is repair the connection, button it all back up and it should be good to go! graemlins/thumbsup.gif

Thats the thing about having a job that sucks the life out of you. I actually enjoy working on cars on my days off. That back fire did get my attention. :eek: Glad to help, and I'll be looking for a good report once you get the bad connection fixed. graemlins/waving.gif

-dnult

Haven't heard from you lately choptop. How's it going? Have you fixed the electrical problem and fried the titties off them new tires yet?

-dnult

Not done with the repairs yet Dave...actually I just got done ordering new harnesses (dash, light and engine) and a serpentine pulley system. After some pondering of the possibilities I decided it was best to replace what I know is damaged (or at least hacked up)instead of trying to "rig" something to work for a while. Hopefully I'll have the parts in hand soon and start replacement right away!

Since I'm on a spending spree, I think Vintage air is calling my name (of course then I'll be broke for sure :( ).

Be sure to filler up with gas before you spend all your money. Take care.

graemlins/thumbsup.gif

-dnult