input needed for no start

[A horse with no name]

Originally Posted by 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

Thanks...I will go and try it out right now... Will get back ASAP.

[A horse with no name]

I haven't jumpered anything yet. I'll send this first for you to have a look.

As you may be able see, my TOP 9th, count from the left, has a 16 Gage black wire and the Bottom has one large red wire with a black stripe.

My TOP 10th, count from the left, has two 16 Gage wires - One is black with a purple stripe, and the other is red with a black stripe.

The Bottom of 10: Two of them are a larger red with white stripes; one is solid red, the last - 4th is red with a black stripe.

The TOP 8th, count from the left, has the large red with a yellow stripe and a 16 Gage red with a black stripe.

The Bottom of the 8th, has one 16 Gage solid black wire.

I have none with a brown wire of any Gage at the top nor bottom of the fuse bar.

[mysocal911]

You have made this troubleshooting effort overly complex. It should only take 5-10 minutes
(15 at the most) to find the problem if you had followed the explicit instructions of the
many helpful posters. You need to re-read this thread!

Again, do you have a good #30 power at the DME relay? That should have been your starting point. You can eliminate all the fuse efforts by focusing on the DME relay and the #30 power and
jumping it.

[ischmitz]

Correct. Connect fuse 9 an 10 at the top.

[ischmitz]

Then run a wire from battery to fuse 10 top and try to start.

[A horse with no name]

Originally Posted by ischmitz

Then run a wire from battery to fuse 10 top and try to start.

Hi Ingo...Unfortunately the relay never 'clicked' when jumping the bottoms of 9 & 10. Jumping from the battery+ to 10 of course was a was a no start, with 9 & 10 jumped.

Is there a way to check 'something' from the secondary ignition/fuel injection stage of the relay? As previously mention, when the points for the pump are manually closed, the pump will turn on. I have held both points closed but also get a 'no start'.

[ischmitz]

So when you place the jumper between fuse 9 and 10 can you verify that you see power on both with the key in RUN? If yes continue to trace the power to the DME relay stage 1.The next 'way station' is the alarm module. A blk/red wire to pin 1 (term15) on the two-pin connector on the alarm module receives power from the ignition switch and it will come out of the alarm module on pin 4 (87a) on a black wire if no alarm condition is present. So both connectors need to be plugged in. If you eliminate the alarm module you need to jumper pin 1 (term15) to pin 4 (term87a) on the harness to the alarm module.

Ingo

[A horse with no name]

Re: " between fuse 9 and 10 can you verify that you see power on both with the key in RUN?"...Yes, the power is coming from 10 to 9. Both had power but no action on the relay.

The alarm has not been used for years, mainly due to a lost key. On the door, the key slot is vertical. Because it could be the problem, I jumper'd it, as you described, a few days ago.

Can you suggest any thing else to test?


Thanks so much for your input. Much appreciated.

[mysocal911]

A simple step at this point is to use two paper clips to jumper/bypass the DME relay:
30 to 87 & 30 to 87b on the connector for the DME relay. At this point the engine should
run. If it does, then you would work back to determine why the relay doesn't function, e.g.
wiring/fuses/alarm. If it doesn't, then work forward to determine what can be causing the ECU
to not function, e.g. reversed pickup sensors, bad ECU, etc. You can then verify that power is
on pins 1, 18, 35 of the ECU. It's that simple. It should take 5 minutes at the most to do this.

Sorry for all your wasted effort in possibly being mis-led in troubleshooting in this thread.
Seventy posts in a simple troubleshooting effort is very unfortunate.

[rick-l]

Originally Posted by mysocal911

jumper/bypass the DME relay:
30 to 87 & 30 to 87b on the connector for the DME relay. At this point the engine should run.

I think he did that but did not report any results e.g. the fuel pump runs or the DME now has power. Just said the car didn't start.

[mysocal911]

Originally Posted by rick-l

I think he did that but did not report any results e.g. the fuel pump runs or the DME now has power. Just said the car didn't start.

O.K. Then he should have focused his efforts there:
1. Are the sensors reversed? Check the sensor voltages to determine that.
2. Is there an injector pulse? Use the LED tester.
3. Does the ICV vibrate?
4. Check for spark. If a spark, use carb cleaner in the intake to start.
5. Find another 3.2 to plug the ECU in, or send it out for testing.

[A horse with no name]

Originally Posted by mysocal911

O.K. Then he should have focused his efforts there:
1. Are the sensors reversed? Check the sensor voltages to determine that.
2. Is there an injector pulse? Use the LED tester.
3. Does the ICV vibrate?
4. Check for spark. If a spark, use carb cleaner in the intake to start.
5. Find another 3.2 to plug the ECU in, or send it out for testing.

Dave - Rick, thanks again for your input.
All of the above has been done, including numerous other tests.
I have read and applied all of the inputs.

It had been a matter of rechecking everything that was done, including removing the speed and reference sensors. The new O2 and head sensor check out. My old relay that was working including the spare that I have look as new and no cracks etc. can be found in either of them.

The ECU is also as new inside; not even any dust. Under magnification there are no solder flaws. There are a few more re checks to do with the alarm system.

It will come down to a ECU check but I do not no of anyone close by to have checked it out. They are about $850.00 Canadian, which I will spend if that's what it is.

Please understand that 'Ischmitz' fix's these things as a business. His help, including '1986 911 Targa'- a diehard Porsche guy, who is retired electrical engineer, has all 911 electrical manuals, who I communicate back and forth by email, has not as stated in context: "unfortunately you have been provided misleading info' ... It's been the very opposite!

This note in no way is meant to offend you nor anyone else but what you have been suggesting had been posted and tired in several different combinations.

They are just trying to help me check every avenue prior to refurbishing the ECU for, with tax, $650.00 + Canadian.

BTW Dave, I will take contributions if you want to chip in

Take care, and and half a good day.

Again, thanks for both of your inputs.

[A horse with no name]

Some great news for me, at the moment that is, but no prize yet.

Both of the DCE relays are working, one when turning to ACC, and the second one closes when the starter engages. The ICV is now humming away, 'but' I do not have spark at the plugs. It appears that I'm now as close as I can get, at the moment, to hearing it run again.

On the ECU connector:

Power on:
1+

14+
15+

18+
20+
35+ with a smaller amount?...On 34 and 33.

I had one big sigh of relieve after I finally found out what the the cause was for having no 'power'... Of all things, it was due to having dirty points in the the alarm module!.. Crazy eh! It was a 'check' suggestion from '1986 911 Targa'.

Now, if someone won't mind to continue to assist me, I need to know how to check for a 'no spark' issue. It would be much appreciated...Thanks in advance!

[mysocal911]

I did a Pelican Forum search and found this:

Simple tests to localize a 911 3.2 no-start problem:

1. Remove the coil wire from the distributor cap and place the end about 10mm
from the engine case.

2. Remove the #1 injector connector and insert a noid light, buy one at
AutoZone/Reillys or Pep Boys.

3. Have someone crank the engine while you monitor both the coil wire & noid light.

Tests results:

A. Both immediate spark and noid upon cranking then;
Both speed & ref sensors, powers/grounds O.K., and DME ECM O.K. - Check for fuel
pressure and/or spray carb cleaner into air filter and re-do steps 1-3 above.
Check distributor cap next. The temp sensor can be bypassed by jumping the
temp connector (white) with a paper clip, which simulates a warm engine.

B. If neither noid nor spark then; check sensors (1k ohms, speed > 1.0VAC,
ref >.10VAC), DME ECM powers (1/18/35) & grds (5/16/17), or DME relay

C. If noid but no spark then; DME ECM a problem, or power to coil from ignition
switch (if already replaced the coil), also check coil wire for resistance.
Once it starts, remove the ref sensor connector, the engine should keep running
and accel perfectly (If not, then a bad speed sensor). Next, try reversing the
speed & ref sensors on the engine and then the two connectors on top,
i.e. To check for a possible weak sensor.

D. If spark but no noid then; power connection to injectors & ECM (pins 14/15) or
bad DME Relay.

Note: The temp sensor, AFM, and altitude sensor affect the fuel and are essentially
eliminated as problem sources for basic starting by using carb cleaner (A above).

The above is a starting point and NOT an exhaustive/in-detail troubleshooting guide.

Here you have not checked for grounds:

On the ECU connector:

Power on:
1+

14+
15+

18+
20+
35+ with a smaller amount?...On 34 and 33.

Have you actually measured the voltage on the sensors, which will verify their proper connections?

It had been a matter of rechecking everything that was done, including removing the speed and reference sensors.

You have not checked for an injector pulse (need your LED thing or noid light) here:

The ICV is now humming away,'but' I do not have any spark at the plugs.The ICV is now humming away,'but' I do not have any spark at the plugs.

[ischmitz]

Ok, now that the ICV is humming you have a powered DME. Great news. The next checks need to focus on the speed and reference sensors. If they are reversed or their gap isn't correct the engine won't fire.

Checking for the speed sensor and whether it's plugged into the correct socket on the engine tower is very straight forward: Disconnect the DME and measure on the harness connector pin 8 and pin 27 with a voltmeter set to AC. When you crank you should see around 2V AC.

For the reference sensor use you LED test light (I seem to remember you built one) and connect it to pin 25 and pin 26 and check for single flash per revolution.

If both tests check out (and please do them again now) your DME needs to issue fuel and spark signals. If not I'd check for the gap of the reference sensor one more time or something inside the DME is wrong.

Ingo

[mysocal911]

You can send the ECU to Pelican for testing and/or rebuilding if necessary. The cost from them
should be less than what you posted early, but do a check in the Pelican Parts catalog.

[A horse with no name]

Originally Posted by ischmitz

Ok, now that the ICV is humming you have a powered DME. Great news. The next checks need to focus on the speed and reference sensors. If they are reversed or their gap isn't correct the engine won't fire.

Checking for the speed sensor and whether it's plugged into the correct socket on the engine tower is very straight forward: Disconnect the DME and measure on the harness connector pin 8 and pin 27 with a voltmeter set to AC. When you crank you should see around 2V AC.

For the reference sensor use you LED test light (I seem to remember you built one) and connect it to pin 25 and pin 26 and check for single flash per revolution.

If both tests check out (and please do them again now) your DME needs to issue fuel and spark signals. If not I'd check for the gap of the reference sensor one more time or something inside the DME is wrong.

Ingo

Thanks Ingo...I haven't tried to see if I have 2V AC when cranking since finding the alarms dirty contact-points issue out late this afternoon. I will, for sure, check it out in the morning.

I have though re-pulled the speed sensor so as to make sure that the gap was correct. It was definitely bottoming out on the ring gear. I then tightened the two bolts up on the bracket.

This time around, the second new sensor, I calibrated my old sensors overall length with the 8mm washer glued to it, and the length of it was spot on. Once I had the new sensor back in, I tested it with the diode that I had soldered a 220 ohm watt resistor onto...It did the trick. The speed sensor, when turning the motor over, lit up very brightly when the diode pins were in 27 and 8 on each revolution, and the reference sensor, on pins 25 and 26 were not so bright, which one would expect. The reference sensor, as you know, is in its own sleeve which allows it to sit at the correct distance from the flywheel once the speed sensor is set correctly.

I did run a continuity test on the car's harness for the three sensors, which also confirmed that they were the correct plugs for the speed and reference sensors at the DCE's connector pins, and in their correct slot on the bracket. Head- Speed- Reference.

Like you just mentioned, it may be within the ECU... I checked around today see if the Porsche dealer that I go to could help me out, but they never had a classic model. They recently had three, but they must have sold them. If I need to have it checked out, the best place for me will be to send it to CA... I'm first though going to replace the alarm module just to make sure, that during my DCE relay tests, that I didn't somehow accidently burn a capacitor, or the likes of, out. That also may be the current reason why that I have no spark.

I'll make a post after I try for the 2 V AC in the morning.

Thanks 'again' for your info.

[DRACO A5OG]

Ah man, sorry to read your troubles.

If I may suggest, start a thread if a Pelican in your area with a 3.2 can allow you to place your DME into their car to eliminate it as a culprit. Note, your DME into their car, not the other way around, if your car is the issue it may damage their DME.

I have lent my car to many local Pelicans to test their DME, I have not had an issue doing this.

Jim

[A horse with no name]

Howdy Jim...Yes, the 'no start' did become quite a frustrating thing to find...To say the least. Alarm contact-points of all things!...One for your notebook eh

Thanks for the good suggestion...I'll make a post right now.

Take care Bud!

[A horse with no name]

Originally Posted by DRACO A5OG

Ah man, sorry to read your troubles.

If I may suggest, start a thread if a Pelican in your area with a 3.2 can allow you to place your DME into their car to eliminate it as a culprit. Note, your DME into their car, not the other way around, if your car is the issue it may damage their DME.

I have lent my car to many local Pelicans to test their DME, I have not had an issue doing this.

Jim

BTW Jim...What years of 3.2's ECU's should I ask for?