coldfire

Hi all,

I've got a 1970 Cutlass S that likes to act up now & again!

The issue I'm concerned with at the moment is as follows.

Amongst other issues, the car does not like idling in stop & go traffic, it will begin to idle rough and occasionally, if I'm not paying enough attention, it will sputter & die. -- That I can deal with --

The problem is, sometimes after I turn the key to the off position and then go to re-fire it - NOTHING HAPPENS - wont crank, no click, nothing. (but interior lights/hazzards/radio etc all still work)

Since it happens on the road, I am not in a setting to really diagnose the problem, and after a time (and me fiddling with wires, jiggling the shifter etc.) it has always EVENTUALLY cranked & fired - as though nothing was wrong.

The hardest part is that it has only happened maybe 3-4 times in the 3 years I've owned it, i.e. once I get it home I can't duplicate the problem, it always behaves, never a problem on cold starts either...

Thoughts? Most likely causes?

oldcutlass

Possibly a heat soak issue, worn solenoid, brushes, yadda yadda yadda. Next time it happens give it a sharp whack with anything that acts like a hammer, while someone turns the key. Clean all your connections and check your cables for corrosion.

oldsman72

Do you have headers by chance? I had a '70 S that would cold-start and run just fine. But wherever I was going I was gonna be there for at least 15-20mins because the car/starter needed to cool down.

coldfire

No, no headers... but your post and the one above are narrowing my symptom search, sounds like it may be a case of heat soak since it's only happened while the engine is hot -- and specifically in stop & go traffic (i.e. extra hot) and always eventually turns over & starts after a while (cooling down)

Other than cleaning/greasing my connections under the hood, any basic/easy recommendations to avoid this reoccurring in the future?

Unfortunately, since it's so intermittent, I won't really know if anything worked until it happens again... or doesn't

MDchanic

Are you sure it isn't the neutral safety switch?

- Eric

coldfire

That did occur to me as well, unfortunately (or FORTUNATELY, more accurately) it has been fine ever since its last episode & this is my daily driver

coldfire

Did it again to me the other day, city driving, got where I was going, parked & shut off... about 5 minutes later went to leave - no click, no nothing.

Was with friends so we just took someone else's car and when we got back it started right up

Kind of embarrassing :P

Still sounds like a heat soak issue
Would a new battery with higher CCA help overcome the resistance in the starting circuit when it's hot under the hood?

Sugar Bear

If the connections are clean and tight then it could be the starter, neutral safety switch or the ignition switch. Because heat soak seems to cause the problem, my guess is that the starter is most likely the problem.

To test the neutral safety switch, take a test light with you, the purple wires at the neutral safety switch should both have battery voltage when the key is in the crank mode. Voltage should go into the switch from one wire and come out of the switch on the other wire when trying to crank the car. If it does not, the switch is defective or out of adjustment.

Would a stronger battery overcome the problem? No. If your battery tests OK than a stronger/higher CCA will not change the problem.

oldsman72

Yep, that sounds like what I used to go through. I wish I could tell you how I solved my issue, but I never did. Car was stolen before I could get that fixed.
(Irony: my car was stolen from a movie theater parking lot in 1992. After investigation, it was determined that car was stolen within 15 mins of me leaving it. Oh sure, THERE it started within 20 mins!! )

Nasty455

Eexternal solenoid would help solve the heat soak problem.

Octania

That wiring looks incorrect to me. It still uses the solenoid on the starter exactly like the stock GM system. All the Ferd relay does is switch... the S wire to the GM starter. Doesn't seem to me to be a lot different from the stock GM feed to the GM solenoid's S terminal.

New solenoid
Inspect starter inside and out
Heat shield [there is one that also serves as a support/ ground strap]
Support/ ground strap
secure all connections

Friend's car had intermittent fail to start, turned out to be the S wire at the starter- the terminal was cooked and breaking. If your wires are all as old as the car, why not run a nice new fat purple wire to the S terminal from the next handy junction in the wiring harness while you are at it?

oldcutlass

Or you can wire it this way:

fordsol.jpg

MDchanic

Funny how of the millions and millions of GM cars sold and used every day from the sixties through the eighties and nineties, none of them needed a F_rd starter relay, but now some think they all do.

If you find and fix the problem, you don't need Rube Goldberg solutions.

- Eric

oldcutlass

This fix has been around for 40 years and it works, Eric. Mine is hooked to a mini starter. The theory is you can run a larger wire directly to the starter with a very short shunt to the S terminal.

MDchanic

Could you explain how this helps a stock starter to work better when hot? (I am not talking about mini-starters, of which I know nothing).

- Eric

oldcutlass

It overcomes thermal resistance in the wiring. There are many web links like this one. As you can see there are both schematics listed in the previous posts.

http://www.crankshaftcoalition.com/w...-_no_hot_start

MDchanic

You posted a link to a crowdsourced web site that offers only generalities, and no clear explanation of why this is better than the original system.

All of the original parts still have to work with this modification, the only change is that you've added another layer of complexity to potentially fail.

I can understand putting a 40A "foglight" relay in the line to the solenoid, as that line can sometimes suffer from resistance after running from the battery through the ignition switch and NSS, and back to the solenoid, but I see no reason why the F_rd relay should make any difference whatsoever.

Also, as I said earlier, "heat soak" was not a problem for the millions of regular folks who used GM cars every day for many years. I will grant that this modification has been around for forty years if you say so, but though it may have been around, it was not used by any measurable portion of those millions of people. If this modification is so necessary, why don't all those cars we see in junkyards have it?

- Eric

oldcutlass

It is a recommended fix when you have headers or an exhaust manifold close to the starter generating a lot of heat. Google remote GM solenoid

oldsmoguy

Now here is a suggestion right from the Rube Goldberg Playbook. Run a #14 gauge wire from the "s" terminal to the battery area leave the purple wire that is on the "s" terminal there, this is in addition to that wire. Do not connect it to the battery. Now when the car doesn't start touch the wire you ran to the positive battery post. If it starts you have a problem elsewhere if it doesn't bad solenoid. Yea, it's a Rube Goldberg thing but since this problem is rare and intermittent it's a start.
I also fail to see how another solenoid in the circuit would solve a heat soak problem. You are still calling the solenoid on that starter to pull in the bendix just the same as the ignition key would. You could pack that new solenoid in ice cubes but if the solenoid on the starter is suffering from heat stroke (soak) it ain't going to pull in that bendix.
Now here is my stupid question of the day, When it wouldn't start you did try to start it in neutral, yes?
Second stupid question, when it wouldn't start did you try hitting the starter/solenoid with a pipe/ hammer or something strong enough to give it a good jolt?
This is just my 2 cents worth of opinion for whatever it's worth.

MDchanic

I have done this to troubleshoot a no-crank problem, after trying everything else I could think of, and it helped clarify the problem quite well
(No-crank, no solenoid click, ammeter goes to -30A, lights dim, test light at purple wire at solenoid lights up just fine, starter and solenoid work fine off the car, new solenoid doesn't cure problem - it was resistance in the purple "S" line - enough voltage got through to light a light, or create a big drain through the solenoid, but not enough to actually pull the solenoid in).



Quite so.

By the way, technically, a Bendix is an inertial throw-out system found on F_rds, though I know that the term is often used to refer to the solenoid throw-out system on GMs as well.

- Eric

coldfire

Yes


Didn't have any tools in the car at the time

Is there a way to test the starter without waiting for it to fail again? Say, in the comfort of my garage as opposed to the side of the road? Lol

Octania

Yes, remove it and bench test it.

beware however my saga of the one that bench tested fine, over and over, but would not work in the car. Because the ground path was not good, because I left that strap off. Don't do that.

I agree that a 2nd wire at the "S" terminal to upstairs would be great to troubleshoot the system with, when you catch it misbehaving. Please use at least #12 or better yet the factory #10 [I think]. #14 might become a fusible link.

And, as I said before, and pointed out above by others, the purple wire and its terminal might just be due for replacement. Wire and terminals and heat shrink are readily available.

https://classicoldsmobile.com/forums...ird-issue.html