Can't figure out my start issue!

[toddetch]

Hi guys!

So, I've been battling a starting issue for a few months. Below, I'll explain everything I've done; however, here is the latest update on my current status... I thought I had it fixed, drove it a few times, and the last time, there was a bit of hesitation (as in, power was on but no starter click for a 1/2 second or so, then it kicked off) when starting as I was leaving my previous errand. When I got home, I realized I hadn't pulled into the garage far enough and couldn't get it to start. I pulled out my phone and captured this video, mainly to capture the sound. This is the first time it sounded like it just couldn't turn the engine over. I'm glad I caught this video because that is the last time the engine seemed to turn. Power is still available, battery is good, starter clicks, etc., but the engine won't turn over. Do you have any ideas from the sound in this video?

I uploaded the video to YouTube: https://youtu.be/MBOs013XwD8

Here is the more extended version of what I have done...

A few months ago, my original style (incredibly heavy) battery died. I replaced it with the Odyssey light-weight AGM in the Rennline battery holder kit. At some point after that, occasionally, it would hesitate a 1/2 second or so before starting - no sound, no clicking, just nothing for the briefest moment before it would start up, and I would be off. I didn't think that much about it, but I guess I should have. On a drive with the local Porsche club, it would start after our rest break. Turn the key; power would come on, but no clicking at the starter, etc. We were able to push-start it and get it home. It seemed pretty cut and dry to me to be a starter issue, so I replaced the starter. After that, the problem was intermittent; sometimes it would start, sometimes it wouldn't. That led me to think maybe I had an issue with the ignition switch. I replaced the electrical part of the ignition switch. Again same problem. Okay, seems to be electrical somewhere else. I really cleaned up the ground connection for the transmission to the chassis and also put a battery monitor on. The battery is good, when running charging is good, but it did show that I had a low cranking voltage. Again, points to maybe something in the wiring. I put a hard start relay in, which was my last fix. The battery monitor still showed a low cranking voltage, but it started and I drove it several times, then what I described above. At one point I did trace the ignition signal from the ignition switch to pin 1 of the 11 pin connector in the driver side of the engine bay and then from there to the solenoid, which all seemed good.

The only idea I have at this point is some weird grounding issue, maybe one of the grounds on the driver side of the engine bay.

Do any of you have any other suggestions?

[wazzz]

Solenoid is engaging normally, otherwise you would hear clicking sounds but no engine turning. On your video it is clear that the engine is turning for brief moments, but not enough power is available at the starter motor to make it turn fast. Indeed that looks like a ground issue if you are sure that your battery is good.

[mysocal911]

Another NO CRANK thread!

[proporsche]

i`d say the battery has no amps..how strong is your battery?? what is your V charging should be 1,8-14,2 any less is not good or more too....
Ivan

[pmax]

Originally Posted by mysocal911

Another NO CRANK thread!

Exactly.

Sounds like the battery/alternator isn’t up to snuff in the OP’s setup.

[emac911]

You changed the battery and noticed starting issues.......I would start with taking the battery back and asking for a replacement or load test. I don't trust many new parts anymore, so much junk being sold nowadays.

[mysocal911]

Originally Posted by pmax

Exactly.

Sounds like the battery/alternator isn’t up to snuff in the OP’s setup.

The point was the post title is misleading! The more appropriate title is; NO CRANK.

[76FJ55]

I agree with the above, suggesting it sounds like a weak battery.

It really helps to specify what you are working on, not that in this case a dead battery would sound any different on a 65 2.0 or a 89 3.2, but sometimes it is critical to the electrical layout or engine management system.....

[toddetch]

Okay, so sorry I used a wrong or "misleading" title. Jeez.

Anyway, thanks for the helpful responses.

I forgot to mention that in order to rule out the battery as an issue, I checked out a loaner H8 battery (the direct replacement) from Interstate yesterday. They told me it had just tested at 1000 cold cranking amps, which should be more than enough. I hooked it up and same thing - turn the switch, power comes on, I can hear the solenoid engage but no clicking and the engine doesn't turn over. It does seem like a ground issue - like something is swallowing the current. The battery monitor tells me the alternator is charging well, and the battery is well charged.

I guess the next step, unless someone has a better idea, is to check all the grounds I haven't specifically checked yet. I checked and proactively cleaned up the ground point at the battery and the transmission. I know there are a couple on the driver side of the engine bay, which I'm afraid are difficult to get to, but since I think that is in the path it could be the culprit.

[76FJ55]

Where is your battery monitor connected? you state that it shows low cranking voltage. if you have a low cranking voltage and a confirmed good battery, this points to a few possibilities.

either

you have excessively high current draw, (the starter is trying (drawing high current ) but incapable of turning the engine. either because the starter is faulty or because the engine is hard to turn.

or

you have a high voltage drop in the system between the battery and the mounting points of the battery monitor due to a high resistance connection causing a voltage drop with starting current.

Still have no idea what year car you're working on.

[toddetch]

Sorry, @76FJ55, I didn't realize I hadn't identified my car and missed that in your earlier message. It's a 1980 911 SC.

I don't think it is the starter because it has worked during this intermittent issue. I'm not discounting your point, but I probably will test other things first.

So, a couple of follow-up questions and comments for you:
1. The battery monitor sits right at the battery, on the posts. When I said it was showing a low cranking voltage, it's something I have been seeing from it. FWIW, during my latest test with the known good Interstate loaner battery, the monitor was not installed and I still had no crank.
2. My guess it is a grounding issue, since I have a hard start relay right at the starter, which should bring the voltage to the solenoid up.
3. Next guess is the positive cable itself.
4. You mentioned the possibility of the engine being hard to turn. What would cause that?

Thanks again for your help!

[emac911]

You did push start before, will it do it again? If so, check voltage at starter as well as "trigger wire" on the solenoid from ignition switch, may have corrosion.

[76FJ55]

Originally Posted by toddetch

Sorry, @76FJ55, I didn't realize I hadn't identified my car and missed that in your earlier message. It's a 1980 911 SC.

I don't think it is the starter because it has worked during this intermittent issue. I'm not discounting your point, but I probably will test other things first.

So, a couple of follow-up questions and comments for you:
1. The battery monitor sits right at the battery, on the posts. When I said it was showing a low cranking voltage, it's something I have been seeing from it. FWIW, during my latest test with the known good Interstate loaner battery, the monitor was not installed and I still had no crank.
2. My guess it is a grounding issue, since I have a hard start relay right at the starter, which should bring the voltage to the solenoid up.
3. Next guess is the positive cable itself.
4. You mentioned the possibility of the engine being hard to turn. What would cause that?

Thanks again for your help!

I guess we should start out with, how much voltage drop are you seeing? voltage dropping into the mid 9s is probably not uncommon during cranking. into the 8s or below would be an indication that you have an issue.

If you are getting an abnormally high voltage drop indicated by the battery monitor, and you have it mounted at the battery posts (I'll assume you actually mean mounted at the battery cable connecting terminals) and you assume that it is a connection issue (not high current draw from the starter), than the only place for the drop to occur is at the interface between the cable terminals and the battery posts. a bad connection or cable after the monitor connection will only limit the current flow and provide less voltage drop at the monitor.

[PeteKz]

If you tried a known good battery, heard the solenoid click, and still got the delay before starting, that points to a problem with the starter. I know you replaced it, but as someone else noted, the replacement parts supply is iffy.

How do you know the solenoid is clicking? Have you put your hand on it while someone turns the key to start? I ask because you might be mistaking something else for the solenoid click.

Measuring the voltage when the engine is cranking is a good idea too. It should be in the 10-volt range with a healthy battery. You will need to disable the ignition to measure this, otherwise the engine will start and run before you can measure it.

Ground connections: Remove, clean and reinstall the ground strap at the transmission. Same for the ground strap/cable at the battery. Make sure the bolts that hold the starter to the tranny are clean and tight.

[ant7]

Have you tried starting it since its cooled down ? Reason being, if its an earth strap issue from Engine/Gearbox to chassis, then it will show up more prominently once the car has been running for a while, this is down to the bad connection increasing in temperature, due to there being resistance at the contact areas on either the engine or chassis, hope this helps, if in doubt; remove the earth strap in question, clean thoroughly the contact areas on the strap and Engine/Gearbox/Chassis, reassemble using a small amount of copper grease on the contact areas.
Ant.

PS, just noticed after writing; Pete in the previous post has also mentioned similar!
Good luck with finding the issue.

[motorstereo]

If you have only cleaned up the ground cables, I would recommend replacing them if they are original. They may appear to be fine, but could be oxidized internally. I had a bunch of electrical gremlins and replaced ground straps when I replaced my engine bay wiring harness (thanks Timmy2 !). After several decades , it was time !

[toddetch]

Okay, thanks to all those who have provided input! I finally got back out there today and did a lot of testing.

- Positive cables are good
- Negative cables are good and grounds are good
- Pulled the starter and shorted it. Plunger pops out but doesn't spin. Bad starter.

I guess Occam's Razor is a thing - the simplest explanation is likely the correct one. Our host is sending me a replacement as I type. I will be bench testing it before installing...

[emac911]

When you hear hooves think horses not zebras.

[911obgyn]

I replaced my starter with the wosp starter from our host and had similar issue. Was going to send it back and bench tested it it worked fine. Ended up cleaning surface where starter mounts and bolts for starter and all good. Had cleaned and checked grounds prior to removing new starter, bell housing where starter mounts was pretty grimy.

[toddetch]

Originally Posted by emac911

When you hear hooves think horses not zebras.

I like that! I'm putting that in my inventory of saying!