input needed for no start

[A horse with no name]

I have had some great help from '86 911 Targa' this afternoon!

He not only sent me 'many pages' from his OEM Porsche Electrical manual, but he also guided me through numerous tests. I still have a 'no start', but at the moment, at least the alarm is now correctly disconnected with the proper jumpers. I'll keep on trying to resolve it...Whatever it is, it continues to be very elusive.

I plan on taking the electrical section of the ignition switch off to see whats happing within. At the moment, the current 'run' position, does power everything that I know of.

The first 'turn' powers pin #86 on the relay which is the cornerstone of everything else to turn on and off in the DME relay.

Has anyone ever had only 'one position' fail on their ignition switch?

[ischmitz]

OK, I re-read your previous comments. fuse #7 and fuse #8 are both powered from the ignition key. They both need to have power when the key is in RUN (or START). If there is no power with the key in RUN it's your ignition switch.

Get a jumper wire and run it from the battery + terminal directly to the top of fuse #7 and then try again to start. Or even easier connect top of fuse #6 and fuse #7 with screwdriver while an assistant cranks.

If the car starts with that you have conclusively shown the ignition switch to be bad. And try that before taking the electrical part of the switch apart. There will be lots of parts coming out and it's not trivial to put it back together.

Ingo

[A horse with no name]

Thanks for the info Ingo... It has to be ay. I have good readings from the speed and reference sensors, including the new head temp sensor. Even both the original and the spare new relay check out. The car is stock, and all of the wiring is in excellent condition. Very clean and pliable.

I'll take the electrical part of the switch out in the am. I assume that I should be able to see where the terminal is worn....Or?

BTW, '86 911 Targa' is on the same page. A 'big' thanks to both of you.

I'll post a reply tomorrow to what I find. I'll order a new switch tonight, whether I need one or not. 99.9% of the reasoning makes me quite sure that I do indeedee need a new one.

Thanks again!

[ischmitz]

Before taking it apart try jumping the fuse #6 and #7 just to make sure. Also get a new part since you might not get all the springs and little pieces back together in the right order...

[A horse with no name]

Originally Posted by ischmitz

OK, I re-read your previous comments. fuse #7 and fuse #8 are both powered from the ignition key. They both need to have power when the key is in RUN (or START). If there is no power with the key in RUN it's your ignition switch.

Get a jumper wire and run it from the battery + terminal directly to the top of fuse #7 and then try again to start. Or even easier connect top of fuse #6 and fuse #7 with screwdriver while an assistant cranks.

If the car starts with that you have conclusively shown the ignition switch to be bad. And try that before taking the electrical part of the switch apart. There will be lots of parts coming out and it's not trivial to put it back together.

Ingo

'I wish' but it is not the ignition switch

[ischmitz]

What happens at the DME relay when you connect fuse #6 and fuse #7 and then turn ignition to RUN?

What voltage do you see at the alarm module connector?

What voltage do you see at the screw terminals of your ignition coil?

Ingo

[rick-l]

Since you can't see electrons moving you can't really tell an electrical component is good by looking at it.

How about if you go back to some of those components you declared good and tell us why you reached that conclusion?

[A horse with no name]

Originally Posted by ischmitz

What happens at the DME relay when you connect fuse #6 and fuse #7 and then turn ignition to RUN?

What voltage do you see at the alarm module connector?

What voltage do you see at the screw terminals of your ignition coil?

Ingo

Hi Ingo...I had checked the black wire on the alarm yesterday, and it had no power with the key on or off. At that time, just to make sure that the alarm was not the issue, I pulled the two separate connectors off of the module and made up two short, permanent, jumpers with spade ends on them, for between #61 -#61 and #87a -#15 terminals on the 8 pin connector.

Fuses:
After putting a jumper from #8 -#7, I then tried to start the car. Still a no start.

Coil: Both sides have 12.8 V.

The coil check :

1. I pulled the coil wire out of the distributor cap.

2. I Attached it to a new spark plug, and grounded it to the ground point on the engine.

3. I disconnected the ignition wire from the coil, and replaced it with a jumper. When lightly touching the other end of the jumper to the ground on the engine - off and on- I got a bright blue spark each time.

Being that it appears not to be the ignition switch, it just may be that the new speed sensor is a dud. I have had it out and rechecked the gap with my new-old 'torched' sensor that does have a 8 mm washer glued to the end of it. The replacement sensor has no marks on it this time around so the clearance is good. Both sensors do test out OK in ohms on the multimeter.

'1986 911 Targa' suggested that I should do a diode test so that I would be able to literally see a pulse, that is if it has one. I'll then be able to check the speed sensor. Hopefully it's dead Installing a new one should technically[/I] make the engine start.

I will let you and others know how the Diode testing goes.

Thanks for your input Ingo, I appreciate it.

Michael
PS- Do you happen to be in competition with the greater L.A.'s 'IN -N-Out Burger' chain with -> 'IN-GO-OUT Burgers'?

[A horse with no name]

Originally Posted by rick-l

Since you can't see electrons moving you can't really tell an electrical component is good by looking at it.

How about if you go back to some of those components you declared good and tell us why you reached that conclusion?

Hi Rick-I...I did so by checking and rechecking. Like multitude rechecks with a high end Fluke multimeter. I did continuity tests, Volts, ohms; tests on numerous wires and components. The checked out values are Porsche's.

Although I am getting the correct reading for the sensors on a multimeter, they are not able to show me if they are sending a pulse. I'm buying some items today so as to give them a dioate test which are able to show if there is a pulse. Sometime today I will be able to confirm if any of the two new sensors are duds or not. Hopefully the speed sensor is. Problem solved....I hope

Thanks for your interest.

[ischmitz]

I wanted you to jumper fuse #6 to #7. Please try that and report back

[A horse with no name]

Will do - #6and#7
Then just try to start or should other multimeter checks be made while jumped?

Thanks!

PS - Being that #8 has 12.8 V , #7 doesn't, and #6 does...What difference will this make than when I used #8?

[ischmitz]

Please check how you count the fuses. See the diagrams below for the fuses. 5 & 6 are powered from A of the ignition switch (hot when ACC and RUN but not hot when START) and 7 & 8 are powered from C (hot when RUN or START).

So you need to short 6 and 7 and then see if the DME relay stage 1 switches when you put the ignition switch to ACC or RUN. Also check if you measure +12V on the coil screw terminal.

The car will not start because fuse 5 & 6 loose power once you crank. If you want to start the engine you need to run a jumper wire from the battery positive terminal to fuse 7 (red arrow). Once you have power there you should have power at the coil and the DME relay and the ICV should vibrate.

Ingo

[A horse with no name]

Hi Ingo...Thanks for the additional info.
First... I tested the ECU connectors speed and reference pins with a diode with a 1/4 watt resistor soldered to it. I got nice, bright, flashes from them when cranking it over - The sensors are OK.

I now understand your reason for jumping #6 & #7 fuses. When turned to AC the pump started. I then jumped from the + battery to #7, but unfortunately still a no start.

12.7 V on both sides of the coil prior to and during the jumper set up. There was also no sounds from the ICV... I previously did clean it with carb cleaner and it 'rattled' freely when shook. Mind you, it did before I cleaned it.

Do you have any other suggestions?

[mysocal911]

Originally Posted by A horse with no name

Hi Ingo...Thanks for the additional info.
First... I tested the ECU connectors speed and reference pins with a diode with a 1/4 watt resistor soldered to it. I got nice, bright, flashes from them when cranking it over - The sensors are OK.

I now understand your reason for jumping #6 & #7 fuses. When turned to AC the pump started. I then jumped from the + battery to #7, but unfortunately still a no start.

12.7 V on both sides of the coil prior to and during the jumper set up. There was also no sounds from the ICV... I previously did clean it with carb cleaner and it 'rattled' freely when shook. Mind you, it did before I cleaned it.

Do you have any other suggestions?

Hopefully you didn't plug the two sensors in the wrong connectors, i.e. happens often.
You did say that you got a spark when turning the ignition switch on/off, right?
If so, you probably have power to the control unit (DME). If not, just check three of
the four corner end pins for power (1, 18, 35).

[A horse with no name]

Originally Posted by ischmitz

Please check how you count the fuses. See the diagrams below for the fuses. 5 & 6 are powered from A of the ignition switch (hot when ACC and RUN but not hot when START) and 7 & 8 are powered from C (hot when RUN or START).

So you need to short 6 and 7 and then see if the DME relay stage 1 switches when you put the ignition switch to ACC or RUN. Also check if you measure +12V on the coil screw terminal.

The car will not start because fuse 5 & 6 lose power once you crank. If you want to start the engine you need to run a jumper wire from the battery positive terminal to fuse 7 (red arrow). Once you have power there you should have power at the coil and the DME relay and the ICV should vibrate.

Ingo

Re counting the fuses.
I am manually counting them from 1 forward as they are on the bus.
#6 is the pump. The top has red with a greenie- gold striped wire with one solid red at the bottom. The top red one with the greenie-gold stripe runs to the DME relay.

#7 has nothing on the top and two 16 gage wires on the bottom. A solid black and a green with a fine blue stripe.

# 8 - Top has a large red with a yellow stripe including a 16 gage red wire with a black stripe. The bottom has a single black 16 gage wire.

The car is a Cab with a manual roof. All options with the exceptions of no auto heat nor heated seats.

[A horse with no name]

Alarm voltage.

12.8 V on connector #15 with key OFF.

With key ON - 12.8 V on T- and 30.

[A horse with no name]

Originally Posted by mysocal911

Hopefully you didn't plug the two sensors in the wrong connectors, i.e. happens often.
You did say that you got a spark when turning the ignition switch on/off, right?
If so, you probably have power to the control unit (DME). If not, just check three of
the four corner end pins for power (1, 18, 35).

Thanks for your thoughts Dave... Appreciated. No, all three of the sensors are in their correct connectors. Head - Speed and Crank Sensor. I have also double checked them by running a continuity test from the male plugs to the ECU connector pins- 25 & 26 for the crank sensor and 27 & 8 for the speed sensor.

[mysocal911]

Originally Posted by A horse with no name

Thanks for your thoughts Dave... Appreciated. No, all three of the sensors are in their correct connectors. Head - Speed and Crank Sensor. I have also double checked them by running a continuity test from the male plugs to the ECU connector pins- 25 & 26 for the crank sensor and 27 & 8 for the speed sensor.

The only way to properly know whether you have the sensors connected correctly is to
measure their voltage while cranking, i.e. ref (25, 26) - .10/.20 VAC, speed - (8, 27)
1.0/2.0 VAC. Did you do that? Did you measure the main powers (1, 18, 35)? You obviously
have some power since you get a spark at key on/off. You know you can always jump the
DME relay's #30 power to the proper pins to allow the engine to run and then work backwards
to solve the possible fuse problems.

[ischmitz]

The diagram in my previous post has fuse position per fuse box. When you look at your fuse panel there is a 3-fuse block and then anther block with more fuses right next to it. Your count is off by 3 and you ended up connecting #3 from block 1 (fuel pump) and #4 from block 2 (Term A powered with switch in ACC). Please re-do the test and add 3 to my instruction: Connect (counting from left to right) fuse 9 and fuse 10 at the bottom. Report back.

The 9th fuse is #6 in the diagram and is energized when the key is in ACC. It has red/yel from ignition switch and red/blk black and red/blk at the bottom. The 10th fuse has red/blk from ignition switch and a brown to the anti-theft relay at the top.

With this jumper turn the ignition to RUN and verify the DME relay clicks stage 1 clicks. The fuel pump should NOT start when you turn the key. Then run a wire from the battery plus terminal to the 10th fuse. With that the car should start. If not continue troubleshooting by checking voltages at the coil and whether ICV is vibrating. If not it could be connectors reversed for speed and reference or issues with the chip inside the DME.

Ingo

Originally Posted by A horse with no name

Re counting the fuses.
I am manually counting them from 1 forward as they are on the bus.
#6 is the pump. The top has red with a greenie- gold striped wire with one solid red at the bottom. The top red one with the greenie-gold stripe runs to the DME relay.

#7 has nothing on the top and two 16 gage wires on the bottom. A solid black and a green with a fine blue stripe.

# 8 - Top has a large red with a yellow stripe including a 16 gage red wire with a black stripe. The bottom has a single black 16 gage wire.

The car is a Cab with a manual roof. All options with the exceptions of no auto heat nor heated seats.

[A horse with no name]

No spark or fuel. Only power on ECU connector is #1 and #30 on the relay.

I got the spark by taking the the ignition side of the coil wire off, and then I hooked a jumper to it. This included pulling the coil cable off of the distributor, and by plugging a spark plug into it. I had the plug grounded, and when I brushed the jumper on the same ground, the plug gave off a bright blue spark. So the coil is OK.

The issue has been due to having no power at the injection or ignition/distributor.. It continues to baffle me. If I hold both the first and secondary points in the DCE relay closed the pump will work but the car will not start. The 'emergency jumping method of the relay will not start it.

Ingo's latest info on where to jump it, should have started it, but that also was a no go. No power to the pump or distributor.

Pin # 86 is the one that makes all the magic happen but I can not can power to it. I've also had a lot of input from '1986 911 Targa', who like Ingo, is very good at 911 electronics... I'm missing something but have yet to find out exactly what it is.

After today's checks, it appears that it may be in the ECU itself.

Thanks again.