Trucho-951

I want to share some pictures of my recent Zeitronix Wideband O2 install and contribute back to Rennlist, I’m very grateful for all the rennlisters who have shared their installations tips, searching the rennlist archives has made my installation a fun and successful one. Thanks, Marlon


I bought the Zeitronix wideband kit with boost sensor, but WITHOUT a display, since I would rather review the data sitting at my desk sipping on a cup of coffee (or having a beer) than while zooming around at 6,000 RPM .




Thanks to rennlist, it was easy finding a home for the new wideband O2 sensor



The hardest electrical part for me was finding that darn #21 DME tachometer wire. Well on my 86 951, it turned out to be the 1.5mm green w/ black stripe wire.


Also another tricky part was figuring out how to splice the boost sensor and the aftermarket boost gauge lines into the KLR vacuum/pressure line.

The solution turned up after a few trips to the local OSH hardware store, great tech assistance there. I picked up a couple of 1/8” National Pipe Thread (NPT) brass Tee’s , these are the smallest Tee’s that OSH carries, and also got some brass compression fittings for connecting these plastic lines.

3/16” Compression fittings for the top and bottom KLR lines into the brass Tee’s and a 1/8” compression fitting for my boost gauge line. The great thing about compression fittings is that one can assemble and disassemble as many times as desired and they provide a gas tight seal every time. So next time I need to get in there, I can quickly disconnect and reconnect these lines.




So now I’m enjoying the data logging feature and am able to log: TPS, BOOST, RPM, and AFR. I think this is the minimum monitoring data I can get away with to get a decent picture of what’s going on under the hood.

Z-log

ibkevin

Nice job! This is next on my list..

TRACKIN951

How much did it cost you without the display?

testarossa_td

Thank you for the write-up!

hally

do you know the voltage curve on that map sensor, i wouldn't mind getting one for my tech edge.

edit, from zeitronix:
0.5V 0PSI absolute
4.5V 50PSI absolute
linear

Ian Carr

15 psi at 2900 rpm... not to shabby

Trucho-951

ok, here is a better run, how about 15 psi at 2600 rpm... alas, this is only a k26/6.

chapstic951

Trucho,
I know it has been a while at this point, but I have a question regarding your installation of the Zeitronix WBO2 data logger. When you spliced into pin 21 of the DME for the tach signal, did you have two wires coming from that port? One green and the other green and black?

I noticed that someone had been in to the wiring harness before, they had cut the solid green wire and put in a "two layer" wire, with only the inner wire being used. It is odd, I know. I am hoping someone can identify with me. I do not know what the green and black one is for.

I just completed the install and cannot get my car to start and I have the feeling that pin 22 is the problem.

Trucho-951

Nope, it was a single 1.5 mm green w/ black strip wire. The "two layer wire" that you talk about is most likely a reference sensor "shielded wire", the outside layer wire shields the inside wire from RF interference.

If you are careful, you can unscrew the plastic cap off of the entire DME harness connector, there is a screw at the very end, and then crack it wide open so that you have access to the backside of all the terminal connectors. Then with on Ohm meter, you can probe and run continuity tests to pin point whatever wire you are interested in. hope this helps.

chapstic951

Damn, I was afraid you were going to say that regarding the wire color. I cut into the solid green (shielded) wire. I cannot find the thread, but there was a link to someone who installed the same system and said, "use the green wire from pin 21." I didn't notice that there were two coming out of the same pin at the time of my handy work.

Guess which wire I am splicing into tomorrow? Did I do irreparable damage to the shielded wire since I have to undo my work from today? It was cut inside the firewall, in the passanger compartment.

theedge

Solid green isnt the speed and reference sensors. Theres a few wires that are solid green, and layered but not in the shielded sense. The VR sensors go to multiple pins on the connector anyway so if you hacked into only one wire coming from the connector then that isnt it.

Are you ABSOLUTLY sure that you had the correct pin?

chapstic951

Yep...(real quick, what is a VR sensor?)

As I mentioned, I didn't notice that there were two wires coming out of the same pin, pin #21 on the DME (for the record, the DME is the larger of the two computers in a 951 from 1986 yes?). I didn't look at the other pins but, off hand I don't recall seeing any other wires sharing a pin out.

though, theedge, I did notice there were a few green wires and I quad check my work, and three more times after the car wouldn't start. I was a timid as could be, cutting into the artery of my car, for this exact reason.

I will take a pict in the AM for clarification (and to put my mind at ease.).

theedge

VR (Variable Reluctance) sensors are what the speed and reference are.

If you take some pics ill have a look at them and see if I can spot anything.

chapstic951

My camera is terrible for close up shots, but you can see that there are two green wires going into pin 21 (checked it another 3 times). The skinny green on is actually green and black (on the left) while the thicker solid green is on the right is layered. Should I be using the grn/blk for the tach signal?

theedge

Ok from the 86 Turbo wiring diagrams, there should be two wires coming from there. You do want to use the smaller Green/Black one, its the wire that goes to the tach in the gauge cluster.

That big solid green layered one would in theory work as well, but it goes to the KLR. To get a signal from it for RPM youd have to cut into the very inner wire but I wouldnt do that.

Check that maybe it hasnt pulled loose at the other end, pins 9 and 10 on the KLR (smaller box). Is there still a connection from the outter part of the big green wire to pin 21?