Lately, if you've been following my posts i've been working pretty much non stop on my 88 d150 with a 318. I had it running real good, even in the cold it ran somewhat okay, but as soon as it warmed up it ran like a champ. Well here in upstate ny it is now twelve degrees. It ran terrible cold and even after it warmed up it still had somewhat of a hesitation at low and high speeds. It just feels like it goes in and out of the powerband if that makes any sense. Could this be caused by one of the air sensors either in the throttle body or the air filter housing? I mean, when it was thirty degrees after it warmed up it ran fine, but now that its super cold, i'm wondering if its just too cold for it to run perfect with something that might be defunct. I mean, it does run better when its warm, but it doesn't run perfect. Also if i let off on the gas suddenly or if i've been driving fast for extended periods and come to a stop the oil pressure light comes on. My oil pressure gauge doesn't seem to be working right as its showing low pressure, but i'm not sure what the guage its suppose to read anyway. Could both of these problems be caused by a faulty oil switch? or sending unit, i think they are the same thing? There is 10w-30 in it now and it doesn't leak anywhere. Perhaps faulty oil pump or bad seals? The truck has 54,000 original miles on it. Thanks for the help again.

 

Replaced 02 yet, mine did the same, you would be on gas but it acted like you suddenly let it off and then got back in.

 

yes, all the emissions sensors including the o2 sensor is brand new.