mark kibort

Thanks!

or pin 13 from the ezk that is basically what you are saying, pin 1 on LH?

so, where does that pin 1 or pin 13 from the EZK end up on the fuse/relay panel?

Thanks,

Mark

and here is the EZK that i wanted to post before.

dbrown928

I discovered that through the troubleshooting process someone had replaced the CE from guess what....an automatic car. Removed the relay and it runs.

Initial efforts were correct however, the CPS that was in the car was in fact bad. Shame the previous troubleshooters didn't try that.

Again, thanks to all for the input.

I intend to keep this thread open to complete the PC based o-scope.

John Speake

Excellent ! Have seen that one a few times before :-)

Mark, yes pin 1 LH is fed from pin 13 EZK with a spur off to the tach. What MY is your fuse/relay panel ?

mark kibort

Good news! Glad you resolved the issues.

Thanks John! MY is 1988. the pod is almost removed functional, but loose, so I can see all the connections on the middle main ribbon connector. (which i think goes to the tach)

John Speake

Tach signal from LH1/EZK 13 comes into fuse/relay panel on W1 and goes out to the tach on J11. To find those pins, see diagram in post #9 in this thread. The wire then goes from J11 to pin 2 of conenctor "B" on your dash (assuming that is also MY 88). It is a green wire. Hope that helps !

You can use your multimeter on ac volts to trace the signal if you can run the engine. Otherwise Ohm the wire out out, or use a buzzer .

mark kibort

this thread is awesome! thanks

Ok, get this

the drawing of the relays is wrong. the kickdown relay is XV, not XVII which is the AbS. the bottom connector of the relay (I forgot the pin number, i think 31b) goes to that blue wire at the bottom of the W connector on the fuse panel. on the holbert car, this was cut. off the harness, the blue wire, was jumpered to the green wire on the J connector
(J11). (which also seems to connect to the kickdown relay bottom pin). My thoughts are that my wiring harness blue wire, leading to /or from the W connector (W11) is cut. that could be the issue! I thought because they led to the kickdown relay XV, that it wasnt needed due to it being a 5 speed. Ill re-jumper it like I had on the Holbert car and see if the tach comes alive.

You mean, W11, not W1 below, right? I see how this is all working. I bet that is my issue. too bad i cant start it right now, as I have all the radiator and oil out of the car!

edit: I think on the holbert car, J11 was cut, and the wire that normally leads to W11, was connected (jumpered) there. could it be that the M11 provides the speed output signal as that drawing refers to ? if not, is that yet another speed signal output that leads to somewhere else?

mark kibort

Isnt the unused relay, relay XV, NOT XVII??

other than that, this helped me find my issue I think.

Thanks,

Mark

mark kibort

john! I just checked the continuity between W11, J11 and both go to the green wire on spot 2 on the tack connector at the dash! whoo hoo! but, like I said, the blue wire that goes from the engine wiring harness for W connnector is cut. so, ill jumper it or hey, maybe even replace the connector to the W connector at W11. either way, i think that is the issue. thanks !

mark

davek9

Voltage divider: Want to say I am not the first to post how to make a divider but I think this is the first basic drawing that most should be able to make.
OK I did this in paint let's see how it goes.

Disclamer: I am not responsible if you fry your Notebook, however this has worked for me and Andrew O.

working Demo
http://www.youtube.com/results?searc...rch_type=&aq=f

davek9

Mark I listed that as a '91 but is is not a '91 has three unused all on the top row

3, 5 and 20, Just like 928 specialest relay chart shows, I'll edit my post thanks!

John Speake

Maybe start a new thread for the 'scope ? It is too useful to get buried !

davek9

That is great news, you learn a lot working on these cars, glad it worked out

Let me know if you need more info on how to make the Divider.

DaveK9

Tails

Davek9,
Thanks for the sketch for the Voltage Divider.

All I have to do is buy the parts and make one as well as install the programme on my netbook.

Thanks again,
Tails 1990 928S4 Auto

davek9

That's cool, please keep in mind that most head-phone jacks (male and Female) are three wire, and so is the head-phone cable.
My drawing only denotes using two of the three wires (Left or Right and the shield for ground).

If one were to build two Voltage Divider's in the box, and have two probe inputs, you could use both the Left and Right Audio inputs into the Notebook/PC and have a dual trace scope

Please post your results, I think I'll do a new thread as John Speake has suggested and place a link it to the one that I learned from.

Z

No, the drawing is correct. It's for a '91. The position of the kickdown relay is different in the fuse panel of your car because your's is an '88, and the fuse panels are not the same between the two different model years.

In a '91, it's relay location XVII. In an '88 it's relay location XV.

The plug locations at the bottom of the fuse panel for the signal going to the tach are also different between the '91 and '88. On the '91 it's M11, as pictured in the diagram, and on the '88 it's J11.

It is for a '91. That relay location is for the automatic transmission kickdown relay, so it is a used location in a '91 car that's equipped with an A/T. It's only an unused location in a manual transmission car of that same model year. The location was labeled as "unused" in the diagram because that diagram was made and sent to someone with a '91 manual transmission car, to help him when he was connecting some data logging equipment.

Using potentiometers instead of fixed value resistors makes it variable, for use on different input voltages. It will also let you start out low and increase the voltage going into your sound card as needed if you're not sure of the voltage you're checking, or how much your sound card is happy getting.

The two channel version is handy for comparing two different signals and how they relate to each other. S4 tach and cam position sensor signals: