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No, I was observing that you said you had no injector pulse, and ONE bad wire could do it. . But I must Digress... Stick to SPARK... Spark is your friend..
Im Still leaning in the direction of Sensor wires from the Sensors to the computer... or the gap isn't right...
And you shouldn't have to remove the orange box, Just find the big round plug...that comes out of it...
Ah, I got it re: injector pulse.. disconnect them all to see if the noid lights up while cranking. But, I agree, might as well try for spark first.
Here's my homemade sensor gap tool--I used one of the old sensors. The one that was still in one piece:
I also used another bracket I bought used (broke mine); it came with the aluminum sleeve but not the extra "figure 8" washer. I ordered both washers (thin and thick) and came to the conclusion that the thicker one is correct. I used my tool in the speed sensor hole--the one further out.
I'm pretty confident in the gap. After all, I am getting a good looking speed sensor signal, and if that's set right, then the ref is automatically adjusted, no? The sensor wires seem like a possibility, and perhaps I'll order a set now, but they'll take a little while to get here, so until then, I will hook up the "horoscope" again and see if I can make the sine wave on the reference sensor fit nicely on the screen (and show it in expanded detail).
I'm also thinking of trying Tom's "follow the signal" procedure--probe inside the DME at the chips and see where the signal goes (or doesn't go). What the heck, I'm running out of ideas, and I ain't got no (2nd) DME to try.
There is a unique intimacy developed by poking a measuring device into the TDC hole. My 951 will sleep good tonight.
And so will I. The stud is there—top a bit too shiney for comfort; but, it measures 5mm in height.
I believe that's correct
EDIT: I remember setting gaps with a feeler guauge before putting the bellhousing on; therefore, the shiney stud. Yes, I realized after that the bracket had to come off again to fit the non-slotted bellhousing lol
The polarity of the reference sensor signal is critical, measured at pin 25 (pos) and pin 26 (neg). If the wires are reversed, you will have, a signal, but NO Start.. See Vol 6 of the Turbo, pg 28-21. The signal must go positive first, then negative, as viewed from pin 25, DME connector.
So You have Verified Gap. You had tossed another DME and KLR at it and that didnt work Either. WHAT is the Common Denominator here? Verify that the DME and KLR and actually getting biased up (power). There is a 14 pin plug that is by booster. and it is right next to the hood light switch.. Normally covered by a plastic piece with two screws.. Follow the Green wire for the coil it is PIn1 BTW I assume You Ran ALL the Fuses with a meter or used the handy porsche "TEST" relay.
That 14 pin Connector is KEY.. It carries power for the DME It also Carries the Green Wire for the the Coil. Pin 1 on the DME and pin 1 also on the connector by the booster. So by Rights you should be able to put one lead of an Ohm-meter on pin one of the DME and the other on the Green wire of the Coil and Read ZERO ohm, (or very close). The Other wire to the Coil Comes From the Ignition lock in the car. THAT is a black wire to pin 15 of the ignition lock. I dont know if you disconnected this connector or pushed the wires out of the way to do service but its worth a look at this point. Make sure you have power to those computers. then make sure the wires do not have any opens..
In the DME KLR test procedure, one of the steps involves opening that 14-pin connector and using the VOM on it. I did that step, and the result was proper; however, I will open it back up and do as you suggest.
But first... I am all in scope mode... will try to test for this polarity and to get a clearer pic of reference sensor signal.
The polarity of the reference sensor signal is critical, measured at pin 25 (pos) and pin 26 (neg). If the wires are reversed, you will have, a signal, but NO Start.. See Vol 6 of the Turbo, pg 28-21. The signal must go positive first, then negative, as viewed from pin 25, DME connector.
I Agree with this, However unless he cut and re-soldered the wires or pulled them out of the sockets, the connectors Are "KEYED" Two Tabs on top and one Tab on the Bottom Making 180 degree pug in impossible. Or are you saying the speed and Reference sensor are reversed..?
Agreed, unless you have the harness apart somehow (e.g., pulled out pins in the connectors or cut wires) I'm not sure how you'd reverse the wires. Switching the connectors, on the other hand, is a common mistake. Forget the 30 year old harness labels, check that the reference sensor pins run to 25 and 26, and that the speed sensor pins run to 27 and 8 (from where you disconnect the sensors under the hood to the pins in the main DME connector). Looking for the boost gauge to show "1" with the ignition on and engine off is a decent proxy for DME/KLR power, since that gauge is driven by the KLR and will be dead if the KLR doesn't have power. It doesn't rule out all power issue, but I think you confirmed power and ground at the DME/KLR connectors. Can't remember if you checked power at the coil and/or checked the coil in general? Until you get tach bounce, however, I'd still be looking to confirm you're getting good speed and ref pulses, either raw or post-S100 processing.
(Did your friend reinstall his DME after testing on your car, and did it work fine after being in your car? A million years ago I changed a clutch on an old car and inadvertently trapped a wire between the block and bell housing, which grounded the wire and kept frying parts until I found it...)
Gentlemen, if this scope reading doesn't show healthy (EDIT: I mean clearly) reference sensors, then I don't know what does.
The iPad camera can't seem to film the steady screen signals; so, I took screenshots of what it looks like. In real life, it looks steady and solid as I crank.
Reference on the bottom, speed sensor on top. 1ms / div horizontal, 5v / div vertical; trigger set at 2v, normal. Both channel and trigger DC coupled:
(Did your friend reinstall his DME after testing on your car, and did it work fine after being in your car? A million years ago I changed a clutch on an old car and inadvertently trapped a wire between the block and bell housing, which grounded the wire and kept frying parts until I found it...)[/QUOTE]
+1 We tend to do things like this from time to time.. Thats when you have a That moment when you think... How the hell did I do that, and at the same time you are so happy that you found it....
"On a long enough timeline everyone's mortality rate is zero" - Tyler Durden
"Work on cars long enough and you Will F-Something up"- Me..
03-30-2018 | 02:55 PM
