Jaguar x-type 2003, 160k miles.
Car never stops having issues in the past three yrs of ownership. This time is longer and I can’t seem to get by having her back on the road. Car starts going over 2500 rpm for a second then goes down to under 1000 rpm, cel on p0123, p0223, system engine error, gear box fault. Car can drive 15 mph max, gas paddle no real use only a tiny bit.
I have attempted to open up the throttle body and checked two connections, one w four wire going to position sensor. Votage testing showed incorrect voltage, definitely change between car sitting still, vs key on, vs engine running idle. One wire goes over 10 volts when car in running, one ground wire (I think it is) goes from 0 volt to over 10 v. The other two wire connector was loose but I managed to plug in with a plastic tube ensuring no contact. replaced the wire connector ($19 )yesterday and measured voltage, both around 9.6 v.
All this started w battery sign on a few months ago. I replaced battery, still on, replaced alternator w refurbished one. At one point I disconnected the air box and started the car. Car stopped and since then I never get it running normal.
To continue w fixing, found loose connection on positive cable to fuse box and don’t seem voltage drop in line. The battery measure 12.3 volt in cold, after car started it jumped to 15.05 v.
Wonder if refurbished alternator
Is bad, putting out too much juice and thus causing error in misfire (I redid one cylinder because wire plug wasn’t tight to spark plug).
Meant to get rid of, but limp mode plus a huge door damage from a street parking wrong doing, the car is probably worth a few hundred at most.
I’d like to restore it to when I got it from an auction and then move on.