71 ROADRUNNER NO START ISSUES

[TURBOSCHILZ]

So the ole 71 has been giving me some issues as of late, could sure use some help figuring it out. First off, purchased the car as basically a barn find, in horrible rusty shape. Engine is still all original but car has been completely restored since. Ever since I got the old engine started, seems to run great, but restarting it has always been an issue, the starter just spins, but it acts like it's going to start fire every time, in fact if you leave the clutch in, throttle to the floor, the car almost stays running as long as the starter is engaged like it's keeping it running, but once you let off the key, it dies immediately. Carb seems to be getting plenty of fuel, according to the timing light, all cylinders are firing. New cap, rotor, points, coil, regulator, starter and solenoid. Anybody have an idea what else it could be? Am I missing something?

 

[Don Frelier]

Check power at the ballast resistor in the key run position. Could be a bad ballast resistor.
Sounds like no spark in the run position.
Likely
Could also be a corroded or burnt connection at the bulkhead connector.

The only time you should try and start the engine with the pedal to the floor is if it's flooded.

Make sure the choke sets properly and the fast idle cam gets set on the carb.
I start it with a couple pumps and crank it.
Then maybe 1 more if it doesn't fire after a couple tries.

 

[KillerBz]

I recently was in the exact same boat, my fix was a wire wasn't carrying the 5 to 6 volts to the coil from the ballast just like Don said, once I corrected that it picked right up and ran fine. If you have a meter that would be great place to start.

 

[68BabyBlue]

Had the same issue, corrosion at the bulkhead connector. Restored car, had sat 22 years, still had original connector. No further issues after cleaning the spades.

 

[bobsgtx]

Check voltage at + terminal at coil with key in run position. It should be 8.5 to 9.5. If not check ballast resistor. Battery volts on one side and same 8.5 to 9.5 on the other. I don't remember the wire colors.

 

[DeltaV]

Get a test light and a factory service manual (wiring diagrams).

Nice looking car!

 

[DeltaV]

With the ignition key in the start position (the spring loaded twist to actually start the engine) the 12 volts goes straight out to the coil and bypassing the ballast resistor. This is so you get a good hot spark to start the engine even when the starter motor is drawing a lot of current from the battery. The ballast resistor is a white, rectangular block and probably mounted to the firewall.

It is not uncommon for the ballast resistor to go bad. At that point the car will seem like it is starting when the key is turned all the way to start, but will die as soon as you let the key spring back to run.

That's one thing to check or place to start, but see my comment in post #6.

 

[68BabyBlue]

With the ignition key in the start position (the spring loaded twist to actually start the engine) the 12 volts goes straight out to the coil and bypassing the ballast resistor. This is so you get a good hot spark to start the engine even when the starter motor is drawing a lot of current from the battery. The ballast resistor is a white, rectangular block and probably mounted to the firewall.

It is not uncommon for the ballast resistor to go bad. At that point the car will seem like it is starting when the key is turned all the way to start, but will die as soon as you let the key spring back to run.

That's one thing to check or place to start, but see my comment in post #6.

When I had the same problem with my next GTX a few years later, it was the ballast resistor. I’ve always carried a spare.

 

[TURBOSCHILZ]

Good morning and thanks for all the replies. Okay, I'll definitely start with the ballast resister, I swear it's about the only thing I didn't replace so that would make sense...lol And I will check the voltage to the coil and see what that comes back at. I'll keep you posted.

 

[TURBOSCHILZ]

Thanks for all the help everyone, it was indeed the ballast resistor, pretty much started right up. Might have a few other small issues I need to address however. First off, the choke kinda seems stiff and kinda stayed shut making it a little difficult to get it dialed in. Can someone please verify that this is how the choke should look? Kinda looks a little more skewed than it should be I would think, but what do I know?...lol Also I'm assuming the switch on the clutch pedal is going bad, the one that allows the ignition to crank the engine when the clutch pedal is depressed. When the vehicles warmed up, it hardly seems to work, you depress the pedal, hit the key and notta. Anyone know where to find a replacement, can it be rebuilt, can I just bypass it?

 

[WileERobby]

Neutral safety switch is readily available thru suppliers.

 

[Don Frelier]

Neutral safety switch is readily available thru suppliers.

Without testing your just guessing.
Could be the starter relay, starter itself or even a battery cable.

 

[GTXDAN]

Thanks for all the help everyone, it was indeed the ballast resistor, pretty much started right up. Might have a few other small issues I need to address however. First off, the choke kinda seems stiff and kinda stayed shut making it a little difficult to get it dialed in. Can someone please verify that this is how the choke should look? Kinda looks a little more skewed than it should be I would think, but what do I know?...lol Also I'm assuming the switch on the clutch pedal is going bad, the one that allows the ignition to crank the engine when the clutch pedal is depressed. When the vehicles warmed up, it hardly seems to work, you depress the pedal, hit the key and notta. Anyone know where to find a replacement, can it be rebuilt, can I just bypass it?

View attachment 1580709

Rock Auto is a good place to get parts like that. I posted a new discount code for them that's good until Jan 12.

 

[TURBOSCHILZ]

Is that what that clutch switch is considered, a neutral safety switch? Dan, as per Rock Auto, which I buy from regularly, I don't think they have the carb choke or the safety switch, but I'll double check, I assume it was the switch you were referring to? And I apologize Don, but I'm NO electrician, nor do I really even know how to test things with a multimeter to see if they're working or not. But the starter, relay and battery cables are all new.

 

[WileERobby]

Without testing your just guessing.
Could be the starter relay, starter itself or even a battery cable.

I'm not guessing. I don't guess. I troubleshoot. Been doing that for 55+ years. He asked if there was a replacement for "the switch on the clutch pedal is going bad, the one that allows the ignition to crank the engine when the clutch pedal is depressed".

 

[Don Frelier]

Is that what that clutch switch is considered, a neutral safety switch? Dan, as per Rock Auto, which I buy from regularly, I don't think they have the carb choke or the safety switch, but I'll double check, I assume it was the switch you were referring to? And I apologize Don, but I'm NO electrician, nor do I really even know how to test things with a multimeter to see if they're working or not. But the starter, relay and battery cables are all new.

Sorry I wasn't trying to be critical of anyone.
If you can duplicate the problem and simply jump the clutch switch and it starts then there you go.
If the starter relay clicks and it doesn't start then jump the battery stud to the solenoid wire right on the relay and see if it cranks.
If jumping at the relay doesn't change anything then it's most likely starter or battery cable.

Unfortunately new parts these days are mostly junk.
A 20% initial failure rate is fairly common.

 

[TURBOSCHILZ]

No worries at all on this end. I can restore an entire car, rebuild the engine, tranny, do all the bodywork and paint the car, hell I'll even weld in new exhaust but I just absolutely suck at electronics, can usually dumb my way thru it on these older cars, but that's about it...lol

Okay, so there absolutely is no clicking when it doesn't crank, it's just absolute silence. So I'm personally still guessing it's that darn clutch switch. Which I haven't ever seen a replacement for myself. So the next question would be how would you bypass that switch if you chose to do so? Does anyone happen to know what the part number of that switch might be by chance? Thanks again.

 

[71Beeper]

It must look something like this as Brewers sell it.

It says in the description that it can be used on E or B bodies.
It looks like the green wire goes thru the firewall and connects to the starter relay.

 

[TURBOSCHILZ]

Okay, perfect, thank you for that. It does look about right right to me, looks like it's an exchange rebuild service, I'll definitely have to contact them about getting a replacement or getting mine rebuilt. So another question about that ballast resistor, I did a bunch of tuning on the car yesterday, seems to run pretty good for her age. Is that ballast resistor supposed to get hot? After it running for some time yesterday, I touched it and it was QUITE warm, much hotter than the firewall it was mounted to, is that normal?

 

[QuickBpBp]

Those clutch safety switches are ONLY available used or NOS. They never made a replacement aftermarket one that I know of. Brewers sells them restored but expensive if you don't have a good core..