Kuroki924

*Update*
So we had to do some more tweaking and we determined that the idle stabilizer is in fact causing issues, most likely due to being as old as it is. We first got an idea for it when my dad accidentally dropped a very small screwdriver on top of it from about an inch above it and the car totally quit. We tried to start it again and it would crank but not fire, and we couldn't hear the fuel pumps buzzing so we took our handy test light needle and put it in the middle socket of the female end plug on the stabilizer, the pumps buzzed, plugged it back it and it still wouldn't start, due to the same issue. Curious, we bypassed the idle stabilizer (Plugging both plugs on the bottom of it into each other) and the car fired right up, and strong, on the first try. We tried it several times in a row and it consistently started confidently at the first turn of the key every time. It idled and drove beautifully as well, as well as starting up strong on the first try several hours later, with the same impressive performance. I've found a replacement stabilizer, but what are the consequences of leaving it bypassed like that, if any? I really like the way the car runs without it currently, and it has no issue ever starting anymore.

Kuroki924

Update 2.0
Sorry for the bombardment of updates, but we've been learning a lot about and making a lot of progress on our little Black Dahlia and consequently running into new issues as we fix others. So now , as we have that idle stabilizer bypassed, both plugs from the bottom of it are plugged into each other. Still starts and runs okay, only hesitating or sputtering going over bumps, which I haven't quite figured out yet. However, there is a much more pressing issue right now. So those plugs are currently plugged into each other, sitting right under the idle stabilizer. When it rains, this absolutely baffles me, but somehow, water will find its way into the plugs, causing all kinds of running issues and even making the car randomly quit. As a temporary solution, we've dried the plugs out, wrapped electrical tape around them, and taken a chunk of 1" inside diameter rubber hose and wrapped that around it and ziptied it, and we're going to see how it holds out through the next rain showers. But how could water find its way into those plugs? When they're plugged in like that they appear to be fairly sealed, along with the little plastic tabs almost, that lock the plugs in place. It completely baffles my dad and I as to how water can find its way into those plugs. I admire Porsche to no end and still love this car, but I can't help but feel it was a pretty critical design flaw placing an electrical component, let alone one that has dictation over whether or not the car works at all, right at the front of the wheel well like that.

mel_t_vin

Post a couple photos of where you are working and what component(s) you are referring to.

Kuroki924

Sorry for the bad photo quality here, it just got dark out. So this first photo is a bit zoomed out so you can get a good idea of what's going on, then I get in detail. You can see we bypassed the stabilizer, plugging both of the plugs from the bottom of it into each other, then wrapping electrical tape around it to seal out any water.

Kuroki924

Just to add, in the closeup pictures of the stabilizer, that isn't a wire cluster leading up to the left plug of it, it's actually the wire cluster leading up to the ignition control module (Or hall control module according to the Hayne's manual) that is actually fastened right behind the stabilizer.

mel_t_vin

Forgot this was an early car with CIS.

Agree with your assessment...not the best of locations. If this car is driven in the rain, with the headlights up, that box could certainly get wet.

Curious if other 924 owners have experienced this issue. Not sure what to tell you...will the wires allow you rotate that box 180* so the plug ends are pointed down?

Kuroki924

I could certainly give that a shot. Only the stabilizer itself is going bad, presumably due to how old it is. It can't handle much vibration at all without acting up in some way, and we're now suspecting the plugs themselves for the stabilizer are going bad as well. The prongs on the male end plug and the metal sleeves on the female end plug have a certain degree of play to them, very much likely causing a loss of connection, probably causing a few of my issues here. I feel like I could replace the plugs, and the stabilizer. I can find a replacement stabilizer, but the plugs for it I can't be entirely sure. I certainly hope I could find replacements, but I can't help but feel like that's an oddly specific part to try to find. As for rotating the stabilizer box.. I feel like it would certainly help with the issue at hand, allowing gravity to hold the plugs down on top of the box, but I feel like it would only make the plugs even more susceptible to getting full of water. On top of that, I can't even begin to imagine the issues that would arise should water get into that box itself. Should I maybe try to cover the entire unit with something?

mel_t_vin

Could be wrong, but surmised that rotating the box would allow water to run over the plug connectors and prevent water from collecting in the plugs.

Re: covering the area...how warm does that box get? Isn't that a heat sink behind the box? You could move the box away from the heat sink, isolate it with rubber bushings, cover it, and ensure adequate ventilation.

Kuroki924

Yes, that is a heat sink situated behind the stabilizer, with the ICM sandwiched between the two. Good news though, we're fairly sure we solved the starting and occasional running issue. The metal sleeves on the female end plug were opened too much and the prongs on the male end plug were far too compressed, so they were making a very shaky connection, so going over any kind of bump would cause them to break connection, causing the sputtering and hesitations going over bumps, as well as the occasional no start issue. So we closed those sleeves a bit and opened the prongs up some, and they make a very tight connection now, and before at an idle even so much as touching the wires that come out of the plug would cause the car to quit because the connection was so weak. After we did that adjusting, you could shake the plugs to hell and back and the rpms wouldn't even budge. Starts up consistently every time now, and she handles bumps. Out of curiosity, after fixing both plugs, we plugged them into the stabilizer to see if it would make any difference. The car still started fine, but even so much as a tap with your finger on top of the box would cause the rpms to jump around and eventually the car to quit. So for now we're definitely going to leave it bypassed, as the car runs a lot more reliably with it so. Add that to a new clutch cable (the old one snapped on me testing the car out after fixing the plugs, go figure) and once again she feels like a new beast. I also thought it ran funny upon starting up, but it does at first, only because it needs to warm up for a second, then it's back to purring. Now the only thing left to do is cover the plugs to protect from water, and fingers crossed, we should be in the clear.

mel_t_vin

Congrats on solving your intermittent starting/running issue.

With the idle stabilizer bypassed, suspect you could possibly have some [cold] idle issues at start up, which may/may not become more apparent as the ambient temps continue to drop. As you've surmised, this can be mitigated with a little extra warm up time prior to driving off.

Well done. Happy motoring...

Kuroki924

Well, it would seem as if I've spoken too soon. Yesterday I went to start her up, and nothing. No crank, the dash lights that come on upon turning the key were so dim I could barely see them, and the only gauge that moved at all was the fuel level, so I'm thinking(hoping) I might just have a dead battery. Thoughts? Though the troubling thing is, I have no idea what could have killed the battery. If it helps the thought at all, the night before I drove home from my buddy's house, and upon starting the car and turning the lights on, the lights behind all the gauges cut out after a second of being on, so I just played it by ear on the way home. Could this have anything to do with it?

Kuroki924

*Update*

So we got her jump started and took our chances at the nearest AutoZone, to find (according to their diagnostic gadget) that the battery had about a 50-60% charge, and it also said that the voltage regulator was failing the test. So we had them charge the battery for about an hour, only to find an hour later that the battery had not only not charged at all, but had actually completely lost its charge. So I bought a brand new one, and according to the tests we did after installing it, the battery had a perfect charge, and the voltage regulator had passed the test with flying colors. She still fired up and ran great, (I'd been itching to drive it for the past couple of days so I decided I was going for a quick spin) and I can only assume and hope the issue there was solved. Could the battery have just been a dud? It was only 8 months old, but the new one passed all of the tests with no problem.

mel_t_vin

Could a new battery fail internally/become defective after just eight months...sure.

In my experience, batteries that fail prematurely [typically within one or two years] are prorated for replacement.