Speed Sensor

[Mgardiner1]

I'm going to install my stroker in an 87 YJ with a 91 XJ harness. My 87 is cable driven speedometer, and the 91 has provisions for an electronic sensor. How critical is it that i purchsae the hesco adapter to use both? If the speedo sensor is not plugged in (Its an ECU from a manual XJ, and the YJ is too) will it cause the engine to not run properly?

[Mgardiner1]

*chirp*........*chirp*..........*chirp*


I hear crickets....

[dwg86]

SORRY, CAN'T HELP YA

[Mgardiner1]

Its alright. I have a feeling its not a particular piece that people have a lot of experience with

[yuppiexj]

It will run but MAY stall when coming to a stop.

The ECU uses the speed sensor to raise the idle as you come to a stop.

I read it some where else but this alludes to it. http://www.naxja.org/forum/archive/inde ... 44774.html

You'll get similar symptoms if you use a Manual trans ECU in an AT equipped vehicle.

you may be able to get away with a pass through VSS (find an AT XJ with dealer installed cruise control it will have a VSS that retains a speedo cable output to run the speedo)

[Mgardiner1]

I did a little investigating over at the Hesco forums. I've found more then one thread describing that a malfunctioning or non present VSS will prevent the ECU from learning and adapting to driving characteristics. I guess i'm gettin a VSS/Cable adapter from hesco!

[amcinstaller]

which transmission/transfer case are you using in this project?? any idea how many pulses per mile?

[gradon]

I have a vss cut switch to get past 116(136 is the highest thus far) and yes, if you don't have it connected, it will like to stall when you pull it out of gear/push the clutch in and let it dip below idle. You can give it a little gas to prevent that. Other pts I have to tune the psc1 to give a bump in fuel.

[Mgardiner1]

I have the original NP231 transfer case, and an AX15 out of a 91 cherokee. Both of these items are currently in the jeep.

[amcinstaller]

on my aw4/242 (92 cherokee) the speed sensor was between the transmission and transfer case. im understanding that the adapter housings are different?

[Mgardiner1]

Yes. My speedo cable reads off of the output shaft of the transfer case. It is in the output housing for the slip yoke