: 1999 etc



D'Elegance
09-19-10, 08:45 PM
Hey guys! i got a 99 eldorado etc that all of a sudden out of no where developed a serious misfire and loss of power. it also feels like theres some surging as well. the only code that comes up is a po300. however there is also a u1000 and i belive it was a u1599 or something like that. car has new plugs, wires pcv valve gas filter and fuel pressure regulator. there is no specific cylinder thats misfiring as far as i know. i also checked the plenum for vacuum leaks and came up with nothing. i think the ecm is on its way out but thats just my guess due to the U codes. what do you guys think?

Submariner409
09-21-10, 12:54 PM
................no such U code (1599) - pull them again - all of them, and note whether each is Current or History, come back - post the codes and their definitions.

Are your plug wires connected exactly as in the diagram ??? It's important. Google "waste spark ignition" to find out why.