confirming hot start Options

[jmargush]

I have read several of the hot start (starter related not fuel) and have mixed opinions on the fix as the threads exhibit as well.

I have had the car on the road for 24 years and never had a problem with the stock setup.
then the other week at an autox I shut the car off in grid and it wouldn't turn over enough to start.

Let it cool down and it started fine.

Did some reading when I got home.

At this point I have cleaned all the connections except the one on the transmission.

Cables look good other than the one going to the alternator 9it have some corrosion around the terminal on the starter.

Ran it for 10 or so minutes the other day shut it off let it sit for a few minutes
it started but seemed a bit on the slow side
shut it off and tried again much slower but did eventually start
did it again and it was even slower
next time it wouldn't even turn over.
While doing this I was checking voltage form the ignition wire terminal on the solenoid to negative on battery.

it is down to about volts when trying to start.

so would you say this is confirmation of ignition switch or need for the additional solenoid or might the battery be weak?

[emerygt350]

I have read several of the hot start (starter related not fuel) and have mixed opinions on the fix as the threads exhibit as well.

I have had the car on the road for 24 years and never had a problem with the stock setup.
then the other week at an autox I shut the car off in grid and it wouldn't turn over enough to start.

Let it cool down and it started fine.

Did some reading when I got home.

At this point I have cleaned all the connections except the one on the transmission.

Cables look good other than the one going to the alternator 9it have some corrosion around the terminal on the starter.

Ran it for 10 or so minutes the other day shut it off let it sit for a few minutes
it started but seemed a bit on the slow side
shut it off and tried again much slower but did eventually start
did it again and it was even slower
next time it wouldn't even turn over.
While doing this I was checking voltage form the ignition wire terminal on the solenoid to negative on battery.

it is down to about volts when trying to start.

so would you say this is confirmation of ignition switch or need for the additional solenoid or might the battery be weak?

I don't think this is the solenoid issue. That just stops the starter from doing anything at all. It can be associated with a problem like yours because of the low voltage but in your case it really appears to be a ground or battery issue. You could add an extra ground from the negative battery terminal to the fan shroud (use a nice batt. Cable from a flaps that has two loops instead of the big lead terminal hookup ). There is a nice attachment point just to the right of the distributor. First I would clean the battery ground to the body, the connection from the battery to the starter, and the transmission ground.

How old is your battery?

[jmargush]

Only connection i haven't gotten a chance to check/clean yet is transmission to ground strap.

Ground to body have been cleaned.

Battery is at least 4 yrs old

[Ninja]

I'd install the hot start relay as a diagnostic step.

I believe in them. You can feed the relay from the battery terminal on the starter.

Original is a path from battery to ignition switch to solenoid. About 12 feet long with multiple connections.

The path with a hot start relay could be less than a foot with less connections.

I'd also install a bump start button somewhere in the engine compartment.

One of the members here made a super nice box mount with integral start button on it.

That's what I'll copy on mine.


50% of my "hard to start" cars get fixed with the relay. This is EVERYTHING, not just Porsche.

This rule only applies to old cars that didn't have a relay installed from the factory.

Everything modern I've hit already has a "start" relay installed.

Maybe the manufactures are on to something...

Grounds are SUPER important!

I'm also prone to add grounds, mostly on old stuff that didn't have enough to begin with.

[GregAmy]

I'm a big fan of the relays, too. It really does not make engineering sense to run the solenoid circuit's engagement current all the way up, through a plastic switch, then all the way back.

But an easy test: either get a remote start switch* and mount it to test when the starter isn't turning strongly, or be fluent in how to use a screwdriver on the back of the starter to jump it**. Both bypass the ignition switch circuit.

* Having a remote start switch in the toolbox is useful anyway when using the Cap'n Crusty procedure to adjust the valves from underneath.

** And for the love of everything holy, and your life, make sure it's out of gear and the wheels chocked.

[jmargush]

So i added a relay and still have slow sluggish starts after the starter gets heat soaked.
So it's it possible i need to replace the ignition switch or is it possible the battery is getting weak.
Or starter needs rebuilt?

[emerygt350]

Did you double up on the ground? Run one from the neg terminal on the battery to the shroud.

[BillC]

So i added a relay and still have slow sluggish starts after the starter gets heat soaked.
So it's it possible i need to replace the ignition switch or is it possible the battery is getting weak.
Or starter needs rebuilt?

If the starter is cranking reliably, the ignition switch is most likely not the problem. As long as your battery isn't dying, I would guess that your starter needs to be rebuilt or replaced.

[Superhawk996]

You can avoid throwing parts at this by troubleshooting with a multi-meter.

[emerygt350]

That's hard when it's a high current issue I would throw the 8 dollars at it. If the extra ground cures the ills you know you need to go in and replace and clean your ground straps. If it's still slow you know it's your pos cable or a bad starter.

[Superhawk996]

That's hard when it's a high current issue

No, it’s not.

It’s simply a matter of measuring voltage drops while cranking or attempting to crank. A large cable like a battery positive cable, a battery negative cable, or the trans ground strap should never have more than 0.1V-0.2v voltage drops while cranking or while attempting to crank. If it does you have bad battery cables, bad connections at the cable ends, or bad ground straps. You can tell which is the bad one based on the voltage drop across it.

Sure throw an $8 ground strap at if you’re not good with a multimeter. That’s quick & reasonable. Better yet save the $8 and just use a jumper cable to make that temporary ground while troubleshooting the problem.

But throwing high dollar parts at it as a troubleshooting method is foolish.

https://www.fenderbender.com/running-a-shop...ircuits-part-11

Same principle applies to the battery. You can measure the battery itself. It should be 12.5-12.7v with no load. Measuring directly from battery terminal to battery terminal if the voltage is dropping below 11v when cranking or attempting to crank, the battery is getting weak.

[jmargush]

Did you double up on the ground? Run one from the neg terminal on the battery to the shroud.

The shroud being the body of the stater?
If so how heavy a gauge of wire?

[jmargush]

Did you double up on the ground? Run one from the neg terminal on the battery to the shroud.

The shroud being the body of the stater?
If so how heavy a gauge of wire?

[emerygt350]

The fan shroud. There is a nice convenient hole for a bolt just in front of and to the the passenger side of the distributor.

[jmargush]

The fan shroud. There is a nice convenient hole for a bolt just in front of and to the the passenger side of the distributor.

I'll give that a try when i get back to it the end of the week.
Should it be a fairly heavy gauge wire?

[emerygt350]

The fan shroud. There is a nice convenient hole for a bolt just in front of and to the the passenger side of the distributor.

I'll give that a try when i get back to it the end of the week.
Should it be a fairly heavy gauge wire?

Yes, go to a flaps and get the lawn tractor battery cable.

Something that looks like this.
https://a.co/d/02bThXIK

[jmargush]

Haven't tried another ground yet .

It has been cooler so the hot start doesn't seem as bad, but I am starting to question the battery.
After setting for the afternoon on Saturday it was sluggish to start.

Today i checked resting voltage and it was down to 12.2v.

ON first cold crank battery voltage dropped to 9.1v

Second crank it only dropped to 10.1 and then fired up ready to run.

Does this point to a battery that is on its last leg or hard to tell at this point?

[Superhawk996]

60% SOC isn’t great

The fact that it drops to 9.1v when cranking is basically telling you the battery is on its last leg.

If this is the best it gets after charging the battery it’s toast.