Ignition timing

[Brett Martin]

Question for Mopar gurus.
Late last year, my 318 ‘73 Challenger wouldn’t start. After a few tests, found there was no spark from the ignition module. Ended up wiring in a MSD ignition which worked fine for a few months. Then replaced the non working module for a new one. All was fine.
Took it out cruising a few weeks ago, reversed it into the garage, all was good.
Tried to start it 3 days later, just kept turning over, with no sign of starting.
Although, when I turned the key off, it chuffed back through the carburetor. This I knew was a timing issue.
Did a few more tests, and replaced the coil. It actually ran, but missing severely. Tuned carbie, but had no timing light. It was very fluttery under the throttle peddle.
Sent it to a workshop, turned out timing was 30dbtdc. Dizzy was not loose.
Any ideas guys? It’s got me stumped, just about ready to replace dizzy.

 

[DetMatt1]

Ignition switch could be worn out.
Do you know what condition the engine is in? Rebuilt? Did the place you took it to change the timing after telling you it was at 30 degrees?

 

[Brett Martin]

I bypassed the ignition with a wire from + coil to + battery, no different.
The car was imported into Australia in 2014, I bought it in 2015, apparently had a crate engine installed before being exported from the US. Been running great since I purchased it, until a couple of weeks ago. I’m not sure what the workshop did, he was only interested in working on later model cars, when I found out, I got it picked up and taken to another workshop. I’ll be going there tomorrow. The chap is a Chev wonder, not so much of a Mopar lover, lol. Thought I could get some ideas to try before hand.

 

[Brett Martin]

Yes he did adjust the timing, but it was still running very rough, to the point it was undriveable.

 

[Steve340]

Sounds like it has perhaps jumped a tooth on the timing chain.
Do the basics start with a compression test and check the operation of the valves.

 

[moparleo]

A 318 crate motor ? As stated above, assume nothing. You need tools to do any quality diagnostics/adjustments. How about a picture of your engine compartment so we can get some idea of what you are working with. We may have some Gurus here, but no magicians. It helps to know what carb, manifold, ignition type etc... You need a timing light. Compression/fuel pressure gauge. Vacuum gauge. Basic SAE 3/8" drive socket/wrench set. A few slotted and Phillips head screw drivers. basic wire cutters, pliers, A service manual and a fire extinguisher. It helps a lot to have a friend help you. An internal combustion engine works exactly the same whether it is a Mopar, Chevy or Ford. You need a fully charged battery and good fuel in the tank before you get started.

 

[aussiemark]

Sounds like it has perhaps jumped a tooth on the timing chain.
Do the basics start with a compression test and check the operation of the valves.

That's what I was thinking if it jumped a tooth that would alter both ignition and valve timing. If I was you I would remove the timing cover and check the valve timing and condition of the timing chain and sprockets it won't take long cost a couple of gaskets and just drain the coolant into a clean container and reuse it, at least that way you can eliminate this possibility. Where are you located?

 

[AUSTA]

Checked the basics charged battery ,plugs & leads.
The backfire could have been that you caused the plug to fire when turning off the ignition.
The fact it run fine last time out is a bit odd.
I helped a mate last week he had been cranking his new motor for a week without success
Turned out he had filled up the tank last time out & the fuel was full of water or contaminated .
tried it with a pipe from the fuel pump into some fresh fuel the motor fired up in seconds.
I would do a compression test before stripping the motor down

 

[quapman]

Usually, when you get the kick when letting the key back from the start position, it's a bad ballast resistor or bad ignition switch. No juice in the start position, but power in the run position.

 

[budascuda]

Before taking the engine apart and plastigageing the crank shaft !?!......
Perhaps the last time you drove the car home, the ballast resistor cooled down too fast or... and developed an internal flaw.
Micro fractures in conductive ceramic type materials (like that of the ballast resistors') can delay current from passing through or stop it all together or do both depending on the circumstances.
If the passing of current is delayed, the resistor can now behave a little like a capacitor too.
Imagine, with a capacitor connected to the coil, the coil is now delayed generating the spark,waiting for the capacitor to charge and reach it's threshold. the delay maybe not by 30 degrees but enough to mess things up bad. A faulty coil can do that too but you took care of that.
The guy who said the timing was off by 30 degrees,
should have known that if that were the case, you wouldn't have been able to drive the car home the last time without noticing anything was wrong.
I think quapman is right on!

 

[TRIPLEBLK]

hey guys, anyone ever had a pickup go bad?

 

[quapman]

hey guys, anyone ever had a pickup go bad?

Several times, yes.

 

[moparleo]

Always do the simple stuff first. Good that you charged the battery first. Bypass the ballast and try it. just run a jumper between the ballast connections.

 

[budascuda]

Add the pickup to list of stuff to be checked! Needless to say, the gap is important too.

 

[Brett Martin]

G'day guys, just a bit of an update.
Turned out to be the advance weights in the dizzy, so that problem solved.
Still drawing current from somewhere, flattening the battery within a week. now tracing all the wiring.

Thank you guys for all your ideas, they helped enormously.

Cheers Brett