Could be a dodgy connection for the start up mixture solenoid. You're looking for a connector underneath the throttle housing. The solenoid richens the mixture for starting I had endless trouble: Poor starting and, ccasionally, kangarooing in low gear, and also occasionally high idling speed.
Check the connector is connecting properly.
John
February 2008
check the connections on the short pipes leading into the fuel injection racks. just above the rocker cover at front of engine. especialy if its a v6
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