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