Full-Force

iTrader: (11)

Hooked my wideband up to a guys car and went down the road to log a run to dial in wot a/f. Did a 2500-6500 run and when I came to a stop the car was idling funny and it spit and sputtered under part throttle on the way back home. The a/f also went pig rich to 10:1.

o2 reading looked funny so I switched over to open loop to see if it would atleast stabilize with no luck.

It felt and sounded like not all 8 cylinders were firing.

Owner took car home and replaced o2's, plugs, and wires. Did not help.

Also he had a broken ect sensor at the time and I thought maybe it was switching from closed loop to open loop on the fly from pcm thinking ect was really changing. Also I think fuel and spark reference ect also so owner replaced ect sensor.

He brought it back to me and I started the car and its still running like crap and I noticed the ect was going from 170 or so to -38 or something like that.

It finally quit doing that and the ect leveled off but I dont know why its running like crap.

Im going to check coils tomorrow, plugs, wires, and do a compression test on all cylinders to see if he has an engine problem.

Has anyone else run into anything like this? Any ideas?