The trusty old 4.0 in my XH went bang so I have put a 4.0 from an EL sedan in. Problem is the EL motor was running like a sewing machine right up to parking on my hoist. Prior to the blow up the XH engine was running sort of OK but a bit of a miss (probably head gasket which is what caused the blow up). Before I swapped I did some checks, the EL has a BBM whereas the XH had the earlier manifold, my XH had the connector for the vacuum solenoid control and I checked that the control wire was connected to pin 15 on the eec iv. When I start the engine the BBM butterfly switches over but I cannot get the engine to run smooth. I have tried to do base timing with both EEC units (both are EEC IV) but it seems to go through the process and after removing the bridge on the two left hand pins the engine runs back up to correct idle but the timing light shows the timing to bounce around a bit and it still runs rough, it doesn't want drive off without feathering the throttle to get some revs up and is a bit of a pig to drive. Any advice would be great