Zeitronix datalogging.. weird RPM spikes
 

I started putting around today, logging to see where im at with my air/fuel.. and for hte most part everything reads correctly. The only wierd thing is, the RPMs will spake way high (much higher than the car could ever go).. i was wondering if anyone had any idea why this is.

Re:Zeitronix datalogging.. weird RPM spikes
 

i have the same damn! problem. I my RPM spikes like a bitch and its EVERYWHERE! I usually just go with the trend of the RPM... if you move the line around you'll get a good idea of what RPM range you're in.

Re:Zeitronix datalogging.. weird RPM spikes
 

Kinda glad to hear im not the only one having this prob.. my main complaint isnt the spikes themselves, but hte fact that since they spike so high it screws the scale up of the line and you cant see the highs/lows as easily.. bump for anyone know can help!

Re:Zeitronix datalogging.. weird RPM spikes
 

What setups are you guys running? I'm hooking mine up this weekend so I'll see if I get anything like this.

Re:Zeitronix datalogging.. weird RPM spikes
 

1991 DX hatch.. mpfi conversion
pm6 turboedit, dsm 450s.
negative coil wire tapped at dizzy, ran inside car..

i just got done soldering my tach wire, ill see if that helps it any.

Re:Zeitronix datalogging.. weird RPM spikes
 

obd1 b16

i know the spikes get crazy. I've tried tapping the line on the driver sider where the rpm wire goes to a clip and also tap the line that goes to the distributor... same thing.

I was going to contact zeitronix about it but havent had the chance and just ended up using the lowest value for that range of the rpm as the correct one. if you look at it, it doesnt spike down, it only spikes up so its almost safe to say that the lowest values are the correct ones.

Re:Zeitronix datalogging.. weird RPM spikes
 

Weird... I have never heard of this problem before. It could have something to do with the fact that both of you are tapping your engine speed wire at weird locations... I tapped all my wires on the wiring harness to the ecu, and my Zeitronix has been reading completely solid--no rpm spikes at all.

Re:Zeitronix datalogging.. weird RPM spikes
 

I would have tapped it at the ECU, but afaik there is not a rpm signal going into the ecu

Re:Zeitronix datalogging.. weird RPM spikes
 

Lol...there must be a rpm signal going to the ecu...
How do you think the ecu works then?? in turboedit or uberdata you see the rpm's set at the tables...the ecu needs it to get the right value out of the table

Re:Zeitronix datalogging.. weird RPM spikes
 

thats exactly what i thought also, but ive looked at the ECU pinouts and didnt see a rpm signal wire

Re:Zeitronix datalogging.. weird RPM spikes
 

Seems like i'm not alone with this problem.

I tapped mine at the ECU. It was working fine, but now i aslo got these spikes. Don't know what's up with it.

Re:Zeitronix datalogging.. weird RPM spikes
 

There should be one...

Re:Zeitronix datalogging.. weird RPM spikes
 

The rpm signal that I am using is off of the dizzy, it's the solid blue wire. The ecu doesn't have this wire going to it. I think that the ecu gets rpm from the other wires off the dizzy, mabye it has to calculate it or some ----. But the blue wire is there so that other sources can get the rpm (EX. tach, wideband). I am also getting the rpm spike though.

Where did you guys tap in at the ecu?

Re:Zeitronix datalogging.. weird RPM spikes
 

There is a Blue wire going to the Tach...that's the one you guys are using..
There is also a wire going to the ECU from the ignitor ... it's a white wire.....I traced it and it become green/white...it goes to several other sensors and then to C12 on the ECU......try that one out...it could be that one...
I yet have to install my WBo2

Re:Zeitronix datalogging.. weird RPM spikes
 

i have my SAFC tapped for RPM signal at the ECU. ill look at what pin it is and let you guys know!

or you could go to the APEXI.com website and use the pin they use for the old school afc. i beleive its on the last black plug....

Re:Zeitronix datalogging.. weird RPM spikes
 

here is the link

http://www.apexi-usa.com/productdocu...s_afc_gen1.pdf

here ya go

http://www.newbieforces.com/files/rpm SIGNAL.jpg

Re:Zeitronix datalogging.. weird RPM spikes
 

gracias, i will tap it tomorrow and see if it makes any difference.

Re:Zeitronix datalogging.. weird RPM spikes
 

let me know ur results.. if they are positives i will have to tap mine.

Re:Zeitronix datalogging.. weird RPM spikes
 

I looked at that pin out again, and that pin B5 that the apex diagram says to use, goes to the alternator..

Re:Zeitronix datalogging.. weird RPM spikes
 

Lol...I made a mistake..yes it's B15 on the second plug...I just traced the white wire coming from the ignitor unit to the ECU and it goes to B15 and B17...the white wire splits up in the middle and both B15 and B17 are are white.....you guess you can use either of them.

Re:Zeitronix datalogging.. weird RPM spikes
 

All hail Semnos, Don't hook up the rpm to the blue tach wire, hook it up to the white wire on the ecu at b15/17. It works like a charm, no spikes.

Re:Zeitronix datalogging.. weird RPM spikes
 

;DAnd I haven't even hooked up my zeitronix yet ;D

Re:Zeitronix datalogging.. weird RPM spikes
 

i have the plx m500 and was told to try any injector wire (A1 for #1) instead of the igniter (b15/b17). obd0. ill log again to see if it helps.