Took the car into the city yesterday to visit the Cemetery and place Mothers Day flowers. It has been running flawlessly, So no issues taking it anywhere. Stopped a couple places and it started right up, then it didn't....
Turn the key, hear the fuel pump buzz, turn key to start and nothing.. Did hear the pump buzz again. crawled under the car to check the solenoid wire and it was connected. couldn't get a good grip on it to pull it off.
I was on top of a hill and only had to push it a few feet to get it rolling and it caught right away. Made it home without issue. doing mental trouble shooting on the drive home, I figured either starter of ignition switch. It was charging fine on the drive home.
But pump did buzz when key was turned all the way. which would rule out the switch.
Anyways got it into the garage and up on the lift. and connected a pushbutton starter switch to the solenoid and the starter cranked. then plugged the yellow solenoid wire back on and it started. Whew...
Pulled the wire back off, cleaned the terminal and tightend up the wire end. plugged back on and everything is good now.
BUT, now you have that question in the back of your head. did I solve it or is it an intermittent problem that will rear is ugly head again in the future...
So lets play Devils Advocate here and guess what OTHER things I should check to rule out or eliminate the problem.
I have a wiring diagram here, but have not checked it yet.
Full Version: Another No Start
Not sure if you've already gone down this road, but it sounds a lot like the all-too-common hot start issue. Car starts fine until it doesn't. And always after a drive. Fortunately, it's an easy fix. And probably one i'd make anyway in case there's no hill around next time 
.
Here's a quick link to Mark Henry's excellent write-up.
http://www.914world.com/bbs2/index.php?sho...308904&st=0
.Here's a quick link to Mark Henry's excellent write-up.
http://www.914world.com/bbs2/index.php?sho...308904&st=0
If you suspect a future no start issue, put in a permanent remote starter button.
Find a nice button you like and hook one connection to either of the rear most pins in the 4 pin connector on the left rear of the relay board. Hook the other one to non switched power. Mount the button somewhere that you only know. On a carbed car, the plug is not used, and on an L-jet car, they only have one connection on the plug so this is easy on them. On a D-Jet car, you would have to connect inside the plug for the D-Jet.
If it won't start from the key, use the button. If that doesn't work, then you know it is either the starter or the wire from the relay board to the starter.
It can also come in handy when troubleshooting other issues on the car too.
Find a nice button you like and hook one connection to either of the rear most pins in the 4 pin connector on the left rear of the relay board. Hook the other one to non switched power. Mount the button somewhere that you only know. On a carbed car, the plug is not used, and on an L-jet car, they only have one connection on the plug so this is easy on them. On a D-Jet car, you would have to connect inside the plug for the D-Jet.
If it won't start from the key, use the button. If that doesn't work, then you know it is either the starter or the wire from the relay board to the starter.
It can also come in handy when troubleshooting other issues on the car too.
QUOTE(cuddy_k @ May 8 2020, 10:04 AM) 
Not sure if you've already gone down this road, but it sounds a lot like the all-too-common hot start issue. Car starts fine until it doesn't. And always after a drive. Fortunately, it's an easy fix. And probably one i'd make anyway in case there's no hill around next time
.Here's a quick link to Mark Henry's excellent write-up.
http://www.914world.com/bbs2/index.php?sho...308904&st=0
Thanks for the link. I saw this once before, but of course thought it won't happen to me..
I like the idea that no wires need cut and its easily reversible.
Anyone have a good part number for the relay to use??
I plan on doing this soon. In the meantime I put my pushbutton starter button in my toolbag. Just in case.
Cemetery pic.
Click to view attachment
Thankful I Was
1. On a hill
2. Made it home.
Standard SS-558 is the 6V single small post, works fine at 12V and takes less amps to kick than the 12V.
Standard SS-588 is the 12V two small post, also called SW3
There are many similar switches, you want the 90 degree bracket as explained in the thread.
Standard SS-588 is the 12V two small post, also called SW3
There are many similar switches, you want the 90 degree bracket as explained in the thread.
Do Marks relay conversion by all means,takes the load of the crappy replacement switches that are around,I don't know if the genuine Porsche part is any better as the design has issues besides,this follows on to 924/944 and the VW part with are pretty much the same.
Someone needs to make a reinforced plastic switch cap that won't spit @ the point of the return spring (914rubber
).
Don't assume your switch is ok ,in my case I had random faults over a period of time until the bloody thing finally died
.
Good luck.
Someone needs to make a reinforced plastic switch cap that won't spit @ the point of the return spring (914rubber
).Don't assume your switch is ok ,in my case I had random faults over a period of time until the bloody thing finally died
.Good luck.
Check the body to transmission ground strap before you assume anything.
You need a zero ohm connection between the body and the transmission.
Ohms law: Voltage = Current x Resistance.
A starter can easily draw 50-100 Amps. Let's use 100 to simplify the math.
V=100A x 0.12 ohms ;Therefore the voltage drop across that braided ground cable would be a full the 12 volts.
Even if the resistance was 0.06 ohms you would drop 6 volts across the ground strap. the other 6 volts that is left at the starter motor is not sufficient to pull in the solenoid and crank.
I'm picking extreme examples but the reality is that it doesn't take but a fraction of an ohm of resistance at that ground strap to cause serious problems.
You need a zero ohm connection between the body and the transmission.
Ohms law: Voltage = Current x Resistance.
A starter can easily draw 50-100 Amps. Let's use 100 to simplify the math.
V=100A x 0.12 ohms ;Therefore the voltage drop across that braided ground cable would be a full the 12 volts.
Even if the resistance was 0.06 ohms you would drop 6 volts across the ground strap. the other 6 volts that is left at the starter motor is not sufficient to pull in the solenoid and crank.
I'm picking extreme examples but the reality is that it doesn't take but a fraction of an ohm of resistance at that ground strap to cause serious problems.
C&P from my own post on the voltage drop of 12 feet of wire, the circuit to the dash and back is at least that long and this drop isn't counting switch and fuse box connectors.
QUOTE
Vdrop = IR, basic voltage drop law.
12v at 8 amps on a 12 foot run with 22awg wire will see a voltage drop of 25.83%.
That 12v is down to 8.9v, border line for kicking the Bosch solenoid.
That's not counting the resistance of the connectors, fuse box, switch, age, heat, etc.
I don't know the actual length of the run or if that's the correct size wire, etc., etc.....but its a good enough example to show that a DC circuit has substantial losses even when new.
note same calculation with 20awg wire loss is 16.25%
I'd say obviously heat is a major contributor as this is more than often a "hot start issue".
12v at 8 amps on a 12 foot run with 22awg wire will see a voltage drop of 25.83%.
That 12v is down to 8.9v, border line for kicking the Bosch solenoid.
That's not counting the resistance of the connectors, fuse box, switch, age, heat, etc.
I don't know the actual length of the run or if that's the correct size wire, etc., etc.....but its a good enough example to show that a DC circuit has substantial losses even when new.
note same calculation with 20awg wire loss is 16.25%
I'd say obviously heat is a major contributor as this is more than often a "hot start issue".
I’ve had my 76 2.0 for 20 years and always had hot engine slow start issues. A year ago I put the car up and switched out the starter relay to the 6v Ford relay Mark recommended. One of the better mods I’ve ever made, the car starts up instantly now, hot or cold, every time. Thanks Mark!
Mark’s solenoid is the way to go.
But the switch might already be done for.
Replace the switch and follows Mark’s modification.
But the switch might already be done for.
Replace the switch and follows Mark’s modification.
QUOTE(ClayPerrine @ May 8 2020, 07:10 AM)
If you suspect a future no start issue, put in a permanent remote starter button.
Find a nice button you like and hook one connection to either of the rear most pins in the 4 pin connector on the left rear of the relay board. Hook the other one to non switched power. Mount the button somewhere that you only know. On a carbed car, the plug is not used, and on an L-jet car, they only have one connection on the plug so this is easy on them. On a D-Jet car, you would have to connect inside the plug for the D-Jet.
If it won't start from the key, use the button. If that doesn't work, then you know it is either the starter or the wire from the relay board to the starter.
It can also come in handy when troubleshooting other issues on the car too.
I think I had that problem......................now I carry a long regular screw driver to I can jump start the hot wire relay if it does not start. I think I had two problems, the connections inside the relay box and the hot start wire kept poping off the started, crimped it closed more and not it fits tight on the starter. May have to clean up the connections inside the relay box every couple of years.
QUOTE(Mark Henry @ May 8 2020, 09:26 PM)
C&P from my own post on the voltage drop of 12 feet of wire, the circuit to the dash and back is at least that long and this drop isn't counting switch and fuse box connectors.
QUOTE
Vdrop = IR, basic voltage drop law.
12v at 8 amps on a 12 foot run with 22awg wire will see a voltage drop of 25.83%.
That 12v is down to 8.9v, border line for kicking the Bosch solenoid.
That's not counting the resistance of the connectors, fuse box, switch, age, heat, etc.
I don't know the actual length of the run or if that's the correct size wire, etc., etc.....but its a good enough example to show that a DC circuit has substantial losses even when new.
note same calculation with 20awg wire loss is 16.25%
I'd say obviously heat is a major contributor as this is more than often a "hot start issue".
12v at 8 amps on a 12 foot run with 22awg wire will see a voltage drop of 25.83%.
That 12v is down to 8.9v, border line for kicking the Bosch solenoid.
That's not counting the resistance of the connectors, fuse box, switch, age, heat, etc.
I don't know the actual length of the run or if that's the correct size wire, etc., etc.....but its a good enough example to show that a DC circuit has substantial losses even when new.
note same calculation with 20awg wire loss is 16.25%
I'd say obviously heat is a major contributor as this is more than often a "hot start issue".
Don't get me wrong, Marks hot start relay is generally a great fix. His post above is also spot on about how voltage drop can occur on the solenoid side too.
However, electrical issues don't lend themselves to guess work. Find the root cause and fix.
Damn, it did it again. But I had my push button with me and got it started quickly. But I did have to lay on the ground at a crowded gas station to get it going. Kind of embarrassing.
Drove home put it in the garage and shut it off. Then restarted it TEN times and it worked every time !!??
And it worked great for 4 months.
Ok, I did the Ford starter relay mod that Mark talked about. so there is still an issue. I had already cleaned up the relay plate, but not sure which connections have to do with the starter circuit.
Can anyone point me in the right direction as far as that goes?
Maybe its time for a different ignition switch. Others have said that the switches that are available new are from China and not the best quality.
Can the switch be disassembled and clean the contacts? I'm not doing this until I have another switch in hand.
Drove home put it in the garage and shut it off. Then restarted it TEN times and it worked every time !!??
And it worked great for 4 months.
Ok, I did the Ford starter relay mod that Mark talked about. so there is still an issue. I had already cleaned up the relay plate, but not sure which connections have to do with the starter circuit.
Can anyone point me in the right direction as far as that goes?
Maybe its time for a different ignition switch. Others have said that the switches that are available new are from China and not the best quality.
Can the switch be disassembled and clean the contacts? I'm not doing this until I have another switch in hand.
Did you clean all your grounds ? take off and clean to bare metal the trans strap, battery ground, clean the battery terminals (both +/-) check your fuses ,sometime the fuse block tabs get bent and are hardly touching the fuse.
Start with all the simple stuff first (grounds) and then work towards the harder bits.
Could be the switch, but I think you would have more frequent issues with it.
Start with all the simple stuff first (grounds) and then work towards the harder bits.
Could be the switch, but I think you would have more frequent issues with it.
Next time it doesn't start with the key, let the key back off the "start" position just a little. Play with the position a little. 9 times out of 10, the starter kicks in. Worn spot on the ignition switch.
QUOTE(Mark Henry @ Sep 1 2020, 03:24 PM)
Did you clean all your grounds ? take off and clean to bare metal the trans strap, battery ground, clean the battery terminals (both +/-) check your fuses ,sometime the fuse block tabs get bent and are hardly touching the fuse.
Start with all the simple stuff first (grounds) and then work towards the harder bits.
Could be the switch, but I think you would have more frequent issues with it.
Just finished cleaning all the grounds, by the relay board, under the dash, trans strap and Bat terminals, and at the starter. Just had the starter connections off when I put the Ford relay on and it looked good as did the one by the relay board
Picture or my Ford relay install.
Click to view attachment
the one on the body at the other end of the neg bat cable looked a little tarnished. That would be the main connection from the battery to body ground. Haven't touched that one since I put it together.
Put the Dremel to them and they all have a nice brass shine to them now. then wiped down with Wax and grease remover before putting them back together. (didn't bother with the ones by the headlights)
Should I have used some dielectric grease?
Started it up like 5 times after I was finished and it does SEEM to start a little crisper, But that could be in my mind...
QUOTE(Root_Werks @ Sep 1 2020, 05:45 PM)
Next time it doesn't start with the key, let the key back off the "start" position just a little. Play with the position a little. 9 times out of 10, the starter kicks in. Worn spot on the ignition switch.
I tried multiple times at the gas station wiggleing (?) the key around, didn't help then.
I did order a new Porsche OEM switch, 2-day shipping $$
I'll hold that in reserve, IF it Fuchs with me again I'll put the new switch in.
Time will tell.
QUOTE(Mark Henry @ Sep 1 2020, 01:24 PM)
Did you clean all your grounds ? take off and clean to bare metal the trans strap, battery ground, clean the battery terminals (both +/-) check your fuses ,sometime the fuse block tabs get bent and are hardly touching the fuse.
Start with all the simple stuff first (grounds) and then work towards the harder bits.
Could be the switch, but I think you would have more frequent issues with it.
If i was having this problem, I would chase the mechanical connections that perhaps are moving when the car is being driven - hence the intermittent maddening results.
As Mark says - Focus on the battery cables - remove the battery to chassis cable (NEG) and clean and re-connect. Look for loose or broken connection at the battery connector - had one of these with 1/2 of the cable strands broken......
NEXT do the same with the chassis strap that connects to the Tranny. Clean and reconnect both sides.
You are Plumbing Electrons. When the starter key is turned there are a lot of these felas trying to get around the circuit. If there is any resistance (dirt, rust, etc.) the flow will be impeded (impedance) and starting will be slow.
NEXT do the RED side.
You are very close to getting this fixed - stay at it!
Looks like new (-ish) paint, that's enough to make for bad grounds, BTDT many times.
You may have got it this time, but I'd check the grounds all over to be sure every ground has bare metal contact.
The dielectric grease is a good idea, it also protects any bare metal should you get a bit overzealous cleaning ground points.
You may have got it this time, but I'd check the grounds all over to be sure every ground has bare metal contact.
The dielectric grease is a good idea, it also protects any bare metal should you get a bit overzealous cleaning ground points.
Cleaned all the grounds to shiny brass ( the other day) took if for 35 mile drive today and when I got back to the house it wouldn't start. 
At least I was at home.
Grabbed my pushbutton and connected it to the Ford relay... Nothing... Maybe a bad ground on the relay. ( I hadn't cleaned this one. ) So I hooked a jumper wire to the ford relay bracket to the ground strap. Still nothing.
Disconnected the yellow wire from the Ford relay and plugged the yellow wire back onto the started solenoid, which takes the ford relay out of circuit and Voila it started.
What is happening here? Did the Ford relay choose just this moment to go bad? too much of a coincidence...
I'll take the Ford relay off of the car and bench test it. and go from there.
New ignition switch should be in the mail today, but jumping the Ford relay with the pushbutton kind of takes it out of the running as being bad.
And when connected up as originally wired it worked fine, This time.
I have to have this straightened out before Teenerpaluza in 20 days....
At least I was at home.
Grabbed my pushbutton and connected it to the Ford relay... Nothing... Maybe a bad ground on the relay. ( I hadn't cleaned this one. ) So I hooked a jumper wire to the ford relay bracket to the ground strap. Still nothing.
Disconnected the yellow wire from the Ford relay and plugged the yellow wire back onto the started solenoid, which takes the ford relay out of circuit and Voila it started.
What is happening here? Did the Ford relay choose just this moment to go bad? too much of a coincidence...
I'll take the Ford relay off of the car and bench test it. and go from there.
New ignition switch should be in the mail today, but jumping the Ford relay with the pushbutton kind of takes it out of the running as being bad.
And when connected up as originally wired it worked fine, This time.
I have to have this straightened out before Teenerpaluza in 20 days....
The trans bolt stud area should be shiny clean and the nut tight, the solenoid grounds through the bracket.
QUOTE(Mark Henry @ Sep 4 2020, 01:35 PM)
The trans bolt stud area should be shiny clean and the nut tight, the solenoid grounds through the bracket.
Mark, thanks for sticking with me on this.
I am going to take the multimeter and do some resistance tests from the ford relay bracket to trunk ground and between a couple other points before I take anything apart. Would like to be able to pinpoint a fault rather than just hoping I fixed it.
Don't understand why it would be a HOT start issue. If you have a bad ground it would be bad regardless of the temp, right?
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