1972 - ignition issue

[20cliff72]

1972 Mustang - motor spins over nicely but it is slow to actually start.

Someone replace the factory 302 with another 302. It's not suppose to be a performance motor but it does have an Edlebrock performer "289" intake and a Weber 4-barrel AFB carb.

Tried new points, condenser, cap, plugs and wires - replaced starter solenoid, re-built carb.

Seems like it's not getting enough voltage to the distributor. I know there is a "Start" & "Run" system in place to help start the motor. And I've heard about the "resistance" wire under the dash. But it sometimes will only "start" when you let "off" the key and ignition switch goes to the "run" position.

Like there is no or not enough voltage when it's cranking.

Even tried swapping out ignition with a "Crane elec ignition" kit - didn't fix it. Fact is, I had a lot of trouble with the install of the "kit" like having to trim the "breaker-plate" that the electronics sit on to get the plate to spin around to where the wire is to "exit" the distributor.

It ran pretty nice with the "Crane" stuff in it but it didn't cure the slow start trouble. So I took it out and put the "points" back in.

A friend suggested replacing the ignition switch and/or the distributor or maybe it's the "neutral safety" switch.

Anybody ever experience anything like it?

Thanks,

Cliff

 

[OMS]

Search the site as there was just some info on this

When starting there should be 12 volts direct from the solenoid.

When in the run position voltage comes from the resistor wire.

Don

 

[20cliff72]

Yep - I've tried that, but it won't crank at all until I take the wire off the solenoid going to the coil.

What's really odd, is that wire was hooked-up - and when I became determined to fix the slow start up and run issue and began swapping out to the Crane Elec ignition kit and it didn't fix it, then, when I went back to the points set-up, I had to, then un-hook the wire to get it to crank-up.

Crazy . . .

One of the reasons I put the points back in was the Crane "breaker-plate" was just sort of floating in the dist. - nothing to hold it down in the dist. except for the vacuum advance arm. Then it started back firing out the carb and running really crappy so I went back to the points, something I was much more familiar with. I ran the Crane stuff for about a week before it started all the crappy running issues.

But the slow to start-up issue hasn't changed in all this.

I was hoping someone had experienced an issue with their ignition switch that had a similar my issue.

Problem just seems so, I don't know - "random". Sometimes it'll crank with the solenoid wire, some times it won't.

Thanks for the info - if you think of anything else please let me know.

 

[Jeff73Mach1]

Retarded Timing will cause slow starts.

*fixed it. -72hcode

 

[72HCODE]

don't rule out the starter itself as the problem. the starter could of been rebuilt with less coils. or maybe it has a blown coil on the armature.

have you checked the battery is putting out 12 volts on its own?

if you jump the starter does it spin full power as opposed to the ignition switch and the slow start?

the resistance wire effects the coil not the starter.

do you have an engine grounding strap?

the starter should get full power from the solenoid ground is the engine and back to the body ground through the strap if the engine ground isn't solid that would cause a slow start as the voltage drop would be very high.

 

[Don C]

I would go through and check what 72HCode suggests, proper grounding is critical.

If that doesn't solve your problem you may have two coincidental problems.

One, the ignition switch should provide voltage to the coil when it's in the start position, and you shouldn't have to release it from the start position to get voltage to the coil.

Two, the starter solenoid may be bad or wired incorrectly. Connecting the coil 12 volt feed wire to the solenoid should not be able to keep the solenoid from spinning the starter.

You can do a search in the upper right search box, the coil wiring, adjusting the ignition switch, and solenoid operation and wiring have all been covered many times in this forum.

If you would like to eliminate the points, many of the members (including me) have had good success with Pertronix.

 

[73pony]

I will be able to attest to the pertronix comment next week. Ordered mine. Due to arrive on Tuesday!

 

[midlife]

A poorly conducting starter cable can draw voltage down sufficiently from the battery so that even with full battery voltage, there's not enough voltage to get the engine to start until you let the key go back to RUN. A bad grounding cable from the battery will do the same. Check both cables and the connection to the starter itself.

This was exactly the problem when I first bought my 66: no start until I let off of the key. Root cause: the post on the starter had stripped threads and poor connectivity to the battery.

 

[piper62j]

If the engine has fuel, compression and a good blue spark at the plugs, all that's left is timing.. The engine may have a stretched timing chain.. If all these requirements are in place, the engine has to start and run.. Keep us updated..

 

[Bru]

I too am no expert.

This shade tree meck-a-nic would try running a wire from the + battery to the + coil and jump the solenoid.

This will by pass everything but the engine compartment to help narrow it down.

 

[20cliff72]

OK - lots of good info here guys. Thanks!

The motor has always spun over nicely - full power and all, just wouldn't startup and run.

It's getting it to "run" is the issue. Not a problem with the starter motor spinning the engine over.

I had replaced the "starter" during all this cause it started hanging-up and I'd have to beat on it with a hammer to get it to work again. So I'm goon rule out the starter for the moment.

72HCODE & midlife may have the answer - I need to go over my all "grounding" and the rest of my starter wires.

I'll get a buddy over to help so I can get a volt meter on it to help run things down.

Thanks for all the advice guys!

Cliff

 

[Jeff73Mach1]

Recent thread of a similar nature turned out to be in part caused by an unplugged tachometer. Since it hasn't been mentioned, I hereby mention it.

 

[Hemikiller]

I'll second the grounding verification. My second Mustang had all sorts of ignition issues when I swapped it from auto to manual. Turns out the ground straps were missing and the tranny cooler lines were acting as engine grounds... :-/