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Unhappy Starting problems still...

I did a lot of searching before posting here. I also have done quite a bit of my own experimentation.

My car was pretty much dead in the water with regard to starting via the ignition switch. I tested EVERYTHING multiple ways which led me to my relay board. The starter and solenoid are fine. EVERY grounding point has been checked and scrubbed with a wire brush including the wires, I have tried 2 brand new ignition switches. Still nothing. So I bought two relay boards for further research.

I installed another relay board and "Vroom!" it started... MANY times... until I drove it for about 40 minutes, then it wouldn't start. I thought that it may be due to heat. I have a dual Weber 44 IDF setup on a 2056 motor. I am not certain that the Cylinder Head Temp sensor (CHT sensor) makes any difference on a non-FI motor.

I am able to start the car by running a lead from the positive post to the trigger wire in the wiring harness that leads from the relay board to the starter and also by jumping the bottom left spade in the relay board where the original FI wiring harness connected.

So, I got it started and was able to make several short trips with no problem re-starting. Then I took a drive for about 30 minutes and when I got home it failed to re-start again. Sometimes it doesn't matter if I let it sit for 10 hours, it won't start. It may start via the ignition switch after I have zapped the starter with a screw-driver or by jumping the ignition wire.

I checked the voltage at the trigger wire and it was around 9.5v. The battery was fully charged at 12.6v+ If I remove the starter / solenoid from the circuit I get full voltage, but I know the solenoid and starter are good from bench testing.... and again from jumping it at the relay board.

I got to thinking that the voltage drop could be due to the starter being heat-soaked but when I crawled under to check the temp by feel, it was just warm; I would not say it was anywhere near "hot."

This morning I also gave-in and ordered a hot start relay kit as added insurance even though I can pretty easily start my car by jumping the battery and starter wire... I just didn't want to have to keep starting my car from inside the engine bay (I very recently graduated from laying on my back and jumping the solenoid.)

I am still determined to fix this wiring issue without the use of the hot start relay.

So here are some questions:

1. How HOT does a starter and / or solenoid have to be in order to be considered heat-soaked? The starter and solenoid felt warm but if my food were served at the same temperature I would send it back. Considering I can jump the starter at the relay board directly from the battery doesn't this rule out a heat-soaked scenario? or maybe the length of the circuit (12 to 14 feet I believe) gives a lot of room for voltage drop where as jumping from the battery reduces the distance of the circuit to less than half giving the current less opportunity to drop voltage? I am not a rocket surgeon so I am really reaching here. I don't think it's resistance in the wire because I have checked the voltage via a lead from each of the ignition pins / wires in the wiring harnesses and directly from the ignition switch with the same drop in voltage.

2. Is there something special about the solenoid in a high-torque starter that would correct the no-start issue? I don't want to throw parts and money at it, I am just trying to narrow down the issue.

3. Does the CHT sensor come into play with my carb setup? I have read that it does not, so then why is it connected to my coil? Can I just remove the sensor and seal the hole with a bolt?

I am going to go drink some beers now since I spent half the day working on my car. I hope someone has some answers when I return and that I have the sense to not respond drunk. I know, I expect too much... but not really... I am being silly as it beats being frustrated.

Last edited by frank; 03-22-2014 at 08:00 PM..
Old 03-22-2014, 07:53 PM
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If the CHT sensor were attached to your coil, one of 2 things would happen. (1) If attached to the (+) side, you'd have wires melting (commonly, all the way to the ignition switch) and probably a fire. (2) If attached to the (-) side, the car would never start. Ever. Basically, heat soak can happen any time the car is driven for a while, then parked. The starter may not feel all that hot to the hand. In most cases, a quality rebuilt starter will solve the problem. I prefer genuine Bosch remanufactured starters. If you're going to use a "hot start" solenoid, go all the way and get a 6 volt Ford solenoid. It will work on as little as 4 or 5 volts, so a 2-3 volt drop in your trigger circuit won't matter. Use fairly heavy wire for the installation, and make sure the solenoid is well grounded.

The Cap'n
Old 03-22-2014, 08:39 PM
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Uhhhh..... brain-fart.... The CHT sensor is in the wiring harness that runs from the rear of the relay board to the coil. The CHT sensor does not connect to the coil however.

But my question remains, can I disconnect the CHT sensor or does it still keep the car from starting when the motor is hot?
Old 03-23-2014, 10:45 PM
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Car won't start, particularly when warm, with a disconnected CHT. ECU interprets the open circuit/infinite resistance as cold engine and dumps in fuel. Engine may initially try to fire but then quickly floods.
Old 03-24-2014, 01:48 AM
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Quote:
Originally Posted by frank View Post
Uhhhh..... brain-fart.... The CHT sensor is in the wiring harness that runs from the rear of the relay board to the coil. The CHT sensor does not connect to the coil however.

But my question remains, can I disconnect the CHT sensor or does it still keep the car from starting when the motor is hot?
You're obviously confused about the CHT Sensor wire, which is located in the FI harness, NOT the main engine harness. In the ignition harness there is a power wire for the coil, a wire for the tach, a wire for the oil pressure switch, and a wire for the AAR. That's it, IIRC. Black with red to coil +, smaller black with violet to coil -, green with red to the OP switch, white (or is it red?) taped off. The CHT sensor, located inside the right side upper tin between the intake runners on a FI equipped car, has NOTHING to do with your coil, your carbs, or your problem.

The Cap'n
Old 03-24-2014, 07:30 AM
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Sounds like this is a CRANKING problem, not a STARTING problem. Or both? CHT sensor is irrelevant if your problem is that you have to jump the starter terminals with a screwdriver. if cranking is the issue, then this statement:

"I am still determined to fix this wiring issue without the use of the hot start relay."

...is likely to cause you a lot of grief. A good start with that tactic is replacing all the starter-related wiring from the front to the rear of the car.

Or you could put in a $15 relay in about 15 minutes.

Your call.

GA
Old 03-24-2014, 09:08 AM
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Quote:
Originally Posted by The cap'n View Post
You're obviously confused about the CHT Sensor wire, which is located in the FI harness, NOT the main engine harness. In the ignition harness there is a power wire for the coil, a wire for the tach, a wire for the oil pressure switch, and a wire for the AAR. That's it, IIRC. Black with red to coil +, smaller black with violet to coil -, green with red to the OP switch, white (or is it red?) taped off. The CHT sensor, located inside the right side upper tin between the intake runners on a FI equipped car, has NOTHING to do with your coil, your carbs, or your problem.

The Cap'n
Yep, as quoted, I corrected my comment. It's part of the ignition wiring harness and not connected to the coil.

I wanted confirmation that the CHT sensor has no impact on my setup, so this means it does not have to be connected for my car to operate.
Old 03-24-2014, 12:49 PM
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Originally Posted by GregAmy View Post
Sounds like this is a CRANKING problem, not a STARTING problem. Or both? CHT sensor is irrelevant if your problem is that you have to jump the starter terminals with a screwdriver. if cranking is the issue, then this statement:

"I am still determined to fix this wiring issue without the use of the hot start relay."

...is likely to cause you a lot of grief. A good start with that tactic is replacing all the starter-related wiring from the front to the rear of the car.

Or you could put in a $15 relay in about 15 minutes.

Your call.

GA
It has already caused me a lot of grief... but made me even more determined.

I considered replacing the ignition wire from the ignition switch and all the way to the starter but before doing that, as stated in my original post, I ran a lead from the ignition switch to the starter solenoid and the car still would not start.

I have put in 3 new starters and they crank up immediately after installation however after a few runs the condition returns. I have bench tested the existing starter and it is fine. So it leads me to believe my issue is with heat-soaking or the relay board.

I don't know what to make of the fact that I can jump the starter from the relay board ignition wiring harness.

Maybe I am looking at the wrong wire? Instead of testing the Yellow ignition wire, I should be testing the Red hot wire from the wiring harness to the ignition and from the battery to the relay board. The big black wire from the battery to the starter is new.

As stated in my original post, I did cave-in and order a Bosch relay kit as a insurance but I really want to fix this the right way. My car has not had a starting issue since I posted my original message, even on a long drive but I know it's just a matter of time.

Maybe in the end I will just install the relay kit and forget about for a while.
Old 03-24-2014, 01:01 PM
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Originally Posted by beatnavy View Post
Car won't start, particularly when warm, with a disconnected CHT. ECU interprets the open circuit/infinite resistance as cold engine and dumps in fuel. Engine may initially try to fire but then quickly floods.

There is no ECU.
Old 03-24-2014, 01:02 PM
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Those "3 new starters" wouldn't have come from your FLAPS, would they?

The Cap'n
Old 03-24-2014, 01:46 PM
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Quote:
Originally Posted by frank View Post
Yep, as quoted, I corrected my comment. It's part of the ignition wiring harness and not connected to the coil.

I wanted confirmation that the CHT sensor has no impact on my setup, so this means it does not have to be connected for my car to operate.
Maybe you didn't read what I wrote. The CHT sensor wire IS NOT in the IGNITION wiring harness, not now, not ever.

The Cap'n
Old 03-24-2014, 01:49 PM
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Originally Posted by The cap'n View Post
Maybe you didn't read what I wrote. The CHT sensor wire IS NOT in the IGNITION wiring harness, not now, not ever.

The Cap'n
Haha! You are a SASSY one Cap'n!

I most definitely read what you wrote.

Here is a photo, maybe I am confused again but it looks to me like the CHT sensor wire is coming out of the ignition wiring harness... maybe I should call it the Ignition coil wiring harness after it splits away from the wiring that goes to the starter? And maybe I should be looking into the engine bay when I comment so as to not be going by vague memory too.



Thank you and everyone for the feedback.

Last edited by frank; 03-24-2014 at 04:43 PM..
Old 03-24-2014, 04:40 PM
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Those "3 new starters" wouldn't have come from your FLAPS, would they?

The Cap'n
Yes, they absolutely did come from my FLAPS. I have also suspected the cheapo solenoid. The current starter and solenoid bench test well and I can start them via a direct jump from the battery to the ignition wire in the relay board. I want to understand how the voltage drop is associated to the starter / solenoid. How does the starter / solenoid cause the loss of voltage. I have had no fear in experimenting with my FLAPS starter due to the lifetime warranty. I just go in and get another one. I wouldn't want to experiment with a Bosch since I don't know that it would have the same kind of warranty.

I hate to just through money and parts at something... particularly when I don't have either at my disposal this moment.

If it's a heat-soak issue, with what can I wrap the starter & solenoid?

If the fix is just to get a genuine Bosch starter / solenoid I would be okay with putting one in and never looking back, but I am not convinced yet since the starter I removed was a Bosch that was having the same symptoms.
Old 03-24-2014, 04:56 PM
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What you are showing, right there next to the ignition distributor, is the oil pressure switch, and that green wire goes from there to the oil pressure light in your instrument cluster. This photo shows a 914 cylinder head, and the empty hole near thew left (#3) spark plug is where the CHT sensor goes. With the head installed, this sensor is about 18" from the distributor. This is a CHT sensor:



Now we should be clear. The oil pressure wire does NOT need to be plugged in to run the engine, at least not on this car.
Old 03-24-2014, 06:42 PM
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Yep, that clears it up. I don't have a CHT Sensor installed... and I should have known better since I have a brand new one still in it's packaging from MANY years ago that looks exactly like your photo.

So that rules out a CHT sensor issue.

Another project... hook-up my center console gauges.

So this narrows my issue down to either an electrical issue with my cheapo FLAPS starter / solenoid which is either simply just a crappy starter or it is failing due to heat-soaking. I suppose it could still be my ignition wire or relay board but I have tested them extensively and feel pretty comfortable that it not either. When I get a voltage drop, it goes away when I remove the starter from the circuit (remove the ignition wire from the starter).

With what can I wrap it?

All that stated, it has still not failed since my initial post... but again I feel like it is just a matter of time... but who knows. My car seems to know the worst time to fail, like in Big Sur in the middle of nowhere, or like last week when I was in a suit stopped at a gas-station for fuel and on my way to a funeral. I had to get under my car to jump it... that's when I decided to find a "no-lay-down" method for jumping it.
Old 03-25-2014, 12:45 AM
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Sounds like a poorly rebuilt starter solenoid to me.
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Old 03-25-2014, 10:52 PM
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Quote:
Originally Posted by frank View Post
It has already caused me a lot of grief... but made me even more determined.
...
I don't know what to make of the fact that I can jump the starter from the relay board ignition wiring harness.
...
I did cave-in and order a Bosch relay kit as a insurance but I really want to fix this the right way.
Let me ensure I'm understanding your situation.

- It's a CRANKING problem, not a starting problem.
- It's happening when the car is hot.
- It will crank over every time either via jumping the relay board and/or a screwdriver on the starter solenoid itself.

Is this all correct? If it is, then you do not have a starter problem. If you had a starter and/or solenoid problem, then it would not consistently crank using the jumper and/or screwdriver. The starter is working fine.

You have a wiring problem.

You insist that you want to "fix this the right way." Define "right". Guess what, it's a subobtimal crappy design that has not aged gracefully through the years. Porsche decided, 40 years ago, to run the full voltage of the solenoid through a long wire to the front, through a plastic switch designed circa 1968 for the Beetle, through another long wire back to the solenoid. Over time, that wire degrades, the switch degrades, connections degrade, and when things get hot those wires, switches, and connections can no longer carry adequate amperage to actuate the solenoid.

Thus...the "hot fix relay". Despite those wires, switches, and connections being 40 years old, they can still carry enough amperage to actuate a small relay. That relay, in turn, can carry the amperage to actuate the solenoid. The solenoid, in turn, can carry enough voltage to crank over the starter and start your engine. There's a reason cars have starter relays in addition to the starter solenoid...

You are free to tilt windmills all you want in order to keep the original design - I'm assuming this is a concours build? - but you will continue to beat yourself over the head with a 40-year-old system that, in its best day, was under-engineered. Or, you can install a simple $15 fix and enjoy driving your car.

GA, been there, done that...gave in.
Old 03-26-2014, 04:42 AM
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Let me ensure I'm understanding your situation.

- It's a CRANKING problem, not a starting problem.
I wouldn't call it a "CRANKING" problem as it doesn't crank when I turn the key. I don't even hear a click. There isn't enough voltage to make the solenoid do anything. Perhaps it should be called an ignition triggering problem.
- It's happening when the car is hot.
Typically yes. Usually this issue manifests when the motor is hot... say after 30 or 40 minutes of driving.* However, if I let it cool down overnight, in the morning it will still not start unless I jump it. It has also failed after a short drive to the grocery store about 2 miles away.
- It will crank over every time either via jumping the relay board and/or a screwdriver on the starter solenoid itself.
This is correct. Every time... I have toasted two starters since I started my assessment / testing of this issue. No issues since I narrowed it down to the Relay Board and Starter / Solenoid. I also replaced the relay board recently and it failed once (maybe two times) right after I installed it but hasn't failed since in over 20 starts.


Is this all correct? No, but you are very close. If it is, then you do not have a starter problem. If you had a starter and/or solenoid problem, then it would not consistently crank using the jumper and/or screwdriver. The starter is working fine.

You have a wiring problem.
Most people would be inclined to agree with you as your logic is solid; at least superficially. The Starter / Solenoid bench-tests successfully outside of the car's circuitry. The cars's circuitry tests successfully with the Starter / Solenoid removed from it's circuit. I am not a electro-surgeon but I am not convinced that successfully jumping the posts on the solenoid is a conclusive test. It does prove that there is a current when the posts are jumped from the "Outside". It's doesn't tell me what is happening during "normal" operation on the "Inside." Maybe there is a solder break and when the unit is hot, parts expand and the solder pulls away and fails to complete the circuit. This is a speculative example. I am not savvy enough to tear-down and thoroughly test a solenoid in a way that would satisfy a qualified rebuilder or certified mechanic.
You insist that you want to "fix this the right way." Define "right". Guess what, it's a subobtimal crappy design that has not aged gracefully through the years. Porsche decided, 40 years ago, to run the full voltage of the solenoid through a long wire to the front, through a plastic switch designed circa 1968 for the Beetle, through another long wire back to the solenoid. Over time, that wire degrades, the switch degrades, connections degrade, and when things get hot those wires, switches, and connections can no longer carry adequate amperage to actuate the solenoid.

The "right" way is to not introduce a relay. I do not dispute the points you make here with regard to wire degradation however, as stated in my original post, I replaced the switch twice, I even disassembled and tested one of those new switches so I could understand how it works. I also ran a new lead from the switch, circumventing the relay board, and directly to the solenoid trigger post. The voltage dropped when the solenoid was introduced. So, I am confident it's not the wire. This really could just be a crappy FLAPS solenoid internal wiring issue.


Thus...the "hot fix relay". Despite those wires, switches, and connections being 40 years old, they can still carry enough amperage to actuate a small relay. That relay, in turn, can carry the amperage to actuate the solenoid. The solenoid, in turn, can carry enough voltage to crank over the starter and start your engine. There's a reason cars have starter relays in addition to the starter solenoid...

You are free to tilt windmills all you want in order to keep the original design - I'm assuming this is a concours build? - but you will continue to beat yourself over the head with a 40-year-old system that, in its best day, was under-engineered. Or, you can install a simple $15 fix and enjoy driving your car.
I understand what the relay does, and it will most definitely work as proven by the way I have jumped the car. I had a relay in it since I purchased the car over 17 years ago but I pulled it out and threw it away last year when it failed. It ran fine without it for quite a while.

I did order a Bosch relay kit $13.95 at: w w w . f c p e u r o . c o m for peace of mind, although I no longer worry that I can't start my car. I may just install it and forget about it. I feel as though the relay may be a Band-Aid. In the process I did discover things in my circuit that were not right, and I corrected them along the way. This has been a good albeit frustrating experience.

It's not by any means a concours car but it is damn good lookin' and I like to keep it clean and uncomplicated.







GA, been there, done that...gave in.

I may be giving in too, but I'll be satisfied that I gave it a go.

I think I am subconsciously preparing it for sale and I want it to be correct.

Thank you very much for your feedback.


See my responses in-line above.

Last edited by frank; 03-26-2014 at 09:25 PM..
Old 03-26-2014, 06:32 PM
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See my responses in-line above.
Okey doke. Nothing more I can offer to you here. Good luck.

GA
Old 03-27-2014, 07:25 AM
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