Finally got my MS installed and have been doing some testing prior to trying to start it for the first time.

When the ignition is switched on MS powers the fuel pump for a couple of seconds and then stops the pump if no rpm is detected.

When the pump stops the display on the JAW turns off as well. However the power to the JAW is NOT cut off.

I am controlling both LP and HP pumps using the MS via 2 relays/fuses. JAW/MS/EDIS/Inj power is supplied via a 3rd relay. All 3 relays have the same 12v feed.

If I disconnect the control wire from MS then the pumps obvoiusly dont start but the JAW dislplay does NOT switch off. If I reconnect the control wire while the ignition is on then the JAW display stays ON.

If I disconnect the HP pump only the MS will run the LP pump for a couple of seconds and then turn it off but the JAW display stays ON



Ground for MS/JAW/EDIS is the same but the pumps have separate earths.




Unless I am missing something obvious then the only thing I can think of is a power spike killing the JAW display when the HP pump stops.

What's JAW? What output/connections does it use?

I have heard of various power display problems like the mexican wave effect but never going dead, can you take a feed from another circuit?

Doesn't draw that much so doesn't need a relay in my opinion.

JAW (Just Another Wideband) LINKY

Cheers

Rich

[Edited on 19/4/09 by RichardK]