It's been awhile since I've posted but here is an update on my ole beast. I followed the advise from my last thread and everything worked out great except for one thing she's using to much fuel at idle. So before this I did a lot of checking on my problems compression, plugs, etc and found out when I did my huges plenum kit the gasket held up for a little while but eventually failed causing oil consumption. So I pulled the intake again and this time used the right stuff literally, personally I won't make the mistake of trusting that gasket again. And to anyone using a Hughes plenum kit be wary of the included gasket mine was a failure. So after the intake was done and all back together I filled her up to see if I could get better mileage but alas no such luck. So far she hasn't consumed any oil but I went through almost a full tank and the avg mpg was 7 . Not good so I got a bottle of fuel system cleaner and added that when I fueled up to see if it would help. And I discovered the fuel guzzeling when my water pipes frozen when it got to -50 w wind chill .. I got my heaters going in my pit and sat in my truck while it was thawing out. While at idle in 30 minutes I watched it suck 1/8 of a tank of gas! While driving down the highway and in town It seem to do just fine and only sips on gas but at idle it chugs it. That is my issue. And the kicker is before all this it was gettin 11-14 mpg. I have a few thoughts on what is going on but I thought I would see if anyone else has any ideas what is happening.
Thanks Allpar7

 

What does your fuel pressure look like? Does your temp gauge give you strange readings? (especially at idle....) What temp thermostat you have?

Supposedly, the PCM shouldn't pay any attention to the O2 sensors at idle.... just runs off tables. Got a tuner or anything installed on there??

 

When I checked the fuel pressure it was right on par to what it's supposed to be, I didn't check for bleed off when I did so that is something else I'm planning on doing. Temperature gauge was normal I didn't specifically pay close attention to it but I didn't notice anything out of the ordinary. I think I've got a 180 in for the thermostat but not positive. And no tuner. Basically the only thing that I have not replaced is injectors which there is a possibility of them being bad but I wouldn't think they would be. It's definitely a curious problem alright .

 

180 stat without a tune to compensate for it is not the right way to go. But not liklely the problem either. Accuracy of a fuel gauge with irregular shape is non existent. !/8 tank is not likely 1/8 tank. But you should be getting better than 7mpg.

 

I would almost suspect leaking injectors.......