b-16 ecu speed sensor/vtec
 

I have a b16 swap into an 86 civic h/b & the vtec doesn't work due to not having a speed sensor.

Is there any way to get the vtec to work automatically either by installing a speed sensor or modifying the ecu program?

Roger

Re:b-16 ecu speed sensor/vtec
 

RPM activated switch will do the trick.
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Re:b-16 ecu speed sensor/vtec
 

Will the switch cause the ecu to switch over to the vtec fuel & timing curves?

Re:b-16 ecu speed sensor/vtec
 

Hmmmm...no. I don't know what to tell you about that. Most of the mini-me guys run an RPM switch and don't have VTEC maps to worry about. You might want to figure out your problem.
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Re:b-16 ecu speed sensor/vtec
 

find out what voltage the ecu needs to see from the speed sensor and make a rpm switch to emulate it uses resistors and such.

Re:b-16 ecu speed sensor/vtec
 

Hmmm, pretty sure the speed signal is a pulse per second; which the ECU counts to determine speed. An RPM would just engage the cams but no the high speed fuel/ignition maps.
No direct exp. here, but if you can score a gauge cluster from 88-91 (w/ the
speed sensor mounted in the cluster) you could try and remove the guts and mod your own cluster. :-\ What about the tranny mounted VSS on Tegs.....transplant that...anyone?

Re:b-16 ecu speed sensor/vtec
 

92+ b series uses electronic VSS. Maybe you can use that? What did u hook the speed sensor into that was on the tranny that is in your car right now?

Re:b-16 ecu speed sensor/vtec
 

Can the ghettodyne re-program the chip to ignore the speed sensor & just run off the tach to work the v-tec & maps?

Re:b-16 ecu speed sensor/vtec
 

OK, hold on. Everyone is making this much more complex than it needs to be.

First, what ECU is being used? If it's an OBD0 VTec ECU (PR3/PW0) the program code will read the VSS and compare that to RPM, and activate VTec accordingly.

If it's an OBD0 ECU without VTec, there is no code to read VSS for VTec, because, obviously, there is no VTec code. VTec will have to be activated by an outside source. RPM Switch, V-AFC, that sort of thing. This would not be depending on vehicle speed. Only RPM.

OBD1+ ECUs will be similar to OBD0 VTec ECUs. If everything has been wired correctly during the conversion, the ECU will read the VSS, as this still comes to the ECU.

To address the mapping concern, RPM switches will not modify fuel or ignition tables. That will have to be done through a ROM editing program, or MAP sensor signal scaling device (V-AFC, Field S-AFC, Joseph's MapHack.. things of that nature). These cause the ECU to think it's at a different pressure, and apply less or more fuel accordingly.

An, no, Ghettodyne can do nothing for this issue. Ghettodyne does not support V-Tec.

Now, what ECU is being used, and we can get your question answered.

Re:b-16 ecu speed sensor/vtec
 

I'm guessing it's B16A1 swap, with PW0/PR3, into 4G Civic.

How do you arrive at this is a VSS problem? Are you clicking code 17?

The VSS is in the instrument cluster, driven by the speedo cable. If you are having a speedo cable problem (not seated properly, broken, etc) and/or your gauge doesn't work then check that out. Check your VSS connections. Test with another cluster.