Suz0nda

1999 XJ Body, Auto, 4x4, A/C, Aftermarket Radio
​​​​1998 4.0, PCM, TCM, and Wiring (Distributor Ignition)

So we tore apart a 1998 4.0 after the timing jumped 2 teeth on the crank gear. We set timing, new head gasket, and put it back together only to find it now has no spark whatsoever and it's throwing a code for P1698 NO ENGINE BUS and also a NO TRANSMISSION BUS on both an Innova 5610Pro and Foxwell OBDII Scanner. We flick the key on and off a few times and codes go away until we disconnect battery and reconnect it. Security light does NOT turn on at all even in the IGN ON position during Ign cycle. What's weird about all this is before we changed timing set is it ran fine (Just acted like it was off timing by 30°) and had no start problems, even after sitting for a year with no battery in it.

Brand New parts include Dissy and Hals effect sensor, CPS, Ignition Coil (BWD), Battery, Chassis and Engine Grounds, Head Gasket, Timing Chain and gears, every fuse and relay in the PDC is brand new as well as the ones in passenger kickpanel.

We did the pin test on the PCM and even changed the PCM from a running 1998 XJ, but we still have no power to the ign coil pigtail. Crank/HALS effect sensor tested good, so did coil, and so did the other sensors. It does have a AC pump but the condensor is ripped out. The ASD is acting normal, fuel pump is cycling normal during Ign cycle, and 7-10v is getting to ign coil ONLY when cranking. We tore apart the harness and saw no broken or frayed wires, and all management sesnors a tested good. We are ABSOLUTELY stumped, any ideas?

agreen

Have you taken a look at the pins on the connectors? Specifically the ones at the ECU? If a pin (or a row of pins) got laid down or pushed while connecting, it can cause all kinds of crazy problems.