rough idle, bad milage
#1
rough idle, bad milage
I've got a 97 with a 4.2 and a 5 speed. Was getting oil in the coolant and coolant return pipe rotted off the lower manifold, so I replaced the manifold with a brand new one and a new lower gasket. The problems I'm having were there before all that, just wanted to give a little history. I'm getting really bad mileage, odo doesn't work but I'm only getting about 3 days on a tank of gas, where I was getting almost a week about 6 months ago with the same driving.
Now for some technical data: Bank 2 LTFT stays a pretty consistent 8% higher than Bank 1 at cruising and idle. Hard accel pegs Bank 1 at .8% and Bank 2 at 3.2%. As soon as I let off at cruising speed Bank 2 jumps to around 17% and Bank 1 goes to around 5%. Bank 1 stays there, Bank 2 eventually drops to 12-13%. O2 voltages seem alright, however the downstream on Bank 2 always seems alot lower than the other 4
When the engine is cold it runs great, but once it warms up is when I start getting the rough idle. If I sit for 15 minutes or so with the truck idling (I do service out of it so I do that often for paperwork) then shut it off, it has a hard time staying running the next time I start it, feels like a fouled plug that cleans up with rpms
Now for some technical data: Bank 2 LTFT stays a pretty consistent 8% higher than Bank 1 at cruising and idle. Hard accel pegs Bank 1 at .8% and Bank 2 at 3.2%. As soon as I let off at cruising speed Bank 2 jumps to around 17% and Bank 1 goes to around 5%. Bank 1 stays there, Bank 2 eventually drops to 12-13%. O2 voltages seem alright, however the downstream on Bank 2 always seems alot lower than the other 4
When the engine is cold it runs great, but once it warms up is when I start getting the rough idle. If I sit for 15 minutes or so with the truck idling (I do service out of it so I do that often for paperwork) then shut it off, it has a hard time staying running the next time I start it, feels like a fouled plug that cleans up with rpms
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