getting 3.67 mpg in a 1995 k1500 5.7 with fresh pistons(stock size) and an edelbrock performer camshaft. anybody have any ideas on what to do to make me get any better mpg or is that what i should get with that cam?

 

I don't know what is wrong from the little information given. But there is definitely something wrong. 3.67 is terrible, even a semi gets better.

 

i would look into your fuel system, i have diagrams for my truck with the 5.0 which has the exact same sensors and that but i would check your O2 sensor first and start looking into the injectors. if you have an injector stuck open it will just dump fuel in and check for leaks around the injectors, a broken gasket with spit fuel into the manifold and may or may not throw a code (happened with mine). if the O2 is not reading then it will think that you are running lean and just dumps for fuel in to compensate. could also be that the truck stays in open loop. a cam would not hurt your mileage that bad if any at all. something is wrong fuel related

 

Tell me how you come up with that number ?? even if its true you would have a leak somewere or blowing so much smoke or at least running hot from even 10 mpg to 3 so thats 7 mpg dump tjats alot of fuel going somewere

 

have replace all throttle body gaskets regulator, fuel pump and have no leaks. new o2 sensor, does not stay in open loop goes into closed loop injectors do leak but not enough to cause that problem. have terrible gas smell from behind truck and under hood but no leaks? i ran out of gas put 7 gallons in and went only 26 miles before i had to gas up.
map sensor?
iat?
egr?
transmission? anything like that cause that problem. tranny has 208000 miles on it!

 

If the tranny is slipping bad enough to get that bad of mileage you would know it. The rpm's would be outrageously high.