I just had a shop put in a used motor out of a '99. While in the shop I had the heads checked, and new head gaskets put in. Now I have a rough idle, codes P1313, P1316, P0300 and P0307. Before burning down the previous motor I replaced the exhaust from the manifolds back... minus the O2 sensors. I never had the codes before the used motor.... It has new plugs and plug wires since the install, I put one of my old plug wires on #7 and still running rough... Any thoughts???

Also my lights pulse dim to bright... Volts pulsing from 13 to 15.3... I have checked all grounds from other posts in the forum and should have a new alternator this week... That surely cant cause this can it?

Please help!

 

I had all those codes at one point or another while troubleshooting pretty significant power loss. In my case, I did the same as you...new plugs, new wires, new O2 sensors. Problem continued, until we looked at the ECU and there had been some water ingress. While you're under there, worth checking to make sure the pins and contacts aren't corroded. After replacing the damaged connectors it's back on the road.

 

Alternator regulator sounds like a problem, which is inside alternator. Grounds to check should include the one at the end of the black battery cable to frame by lower part of radiator. You can test the ground issue with a battery jumper cable from (-) battery terminal to that big metal piece that sticks up above the power steering pump.

Rover problems don't usually come to the party alone.

 

I will check out the ECU... The initial problem was the expansion tank blew up while I was up on a trail.. I tried to milk it down the trail so I could get a trailer to it.... Needless to say it melted down.. But the underhood was showered with coolant for a bit.. The ECU very well may have gotten wet. I will check it out and let you know.. Thanks... KCCO!

 

I got the Disco at 135K and the previous owner has detailed records of service and maintenance with no record of the alternator being replaced.. I checked the battery connection, frame connection by radiator, starter connections, the connections in the underhood fuse box, alternator connections... I have an alternator that will be here from BP Utah this week but will throw a jumper on it tonight to rule the ground out. Hope that fixes this issue. Do you have any advice on the codes it is throwing? Do you think the pulsing alternator could effect the system to make it misfire?
Thanks again!