bwiygul

I'll try to make this pretty much to the point.
i have a rebuilt engine that is .20 over, decked and has the engine builder's performance head and torquer cam. i have a test pipe instead of a cat, new TPS, Fuel filter, plugs, wires, cap and rotor, blocked egr, new vacuum lines and O2 sensor. The problem is that most of the time i can't get much over about 72 on the freeway or roads that i can go that fast on. When it's running like this i also can barely pull a gentle grade much more than 55 mph. When it's running like crap it still seems to drive fine up to about those speeds except for the lack of power up the grades and i'm also getting about 13-14 mpg, about 210 miles on a tank. Then for no particular reason something changes and i get about 260 miles on a tank (about 16 mpg which is still MUCH lower than what i used to get before the rebuilt when i was getting about 18-20). I also have a sporadic idle. sometimes it's around 1000 and sometimes it drops as low as 500 and is usually pretty shaky and vibrates the truck. it's also timed at 5 deg BTDC. I've looked around to see if there was anything else on the site to but can't find anything that was close to this but besides the threads about just flat out not power i can't find anything like this. any help would be greatful! thanks.

gofalls

as far as the MPG's, could your ADD be engaging without you knowing it?

bwiygul

ADD? attention deficit disorder? lol?

dropzone

iTrader: (6)

you truck is equipped with Automatic Differential Disconnect unless it has manual hubs

also might wanna say what engine; 4 cyl or v-6

fireman1559

first off with the ADD system it can not just engage into 4wd. it almost sounds like a vaccum leak somewhere or the timing belt is starting to break

mightymouse

iTrader: (6)

First off if your motor is the 22re, wich is what i gathered by reading you post I.E. cam, Advance your timing a little. Seriously just a little at a time! I have a similiar engine and it respnds well to the advance. There is a little adjustment screw next to the distributor that allows you to rotate it. Check your plug gap. mine is at .04 and your wires ( i'm running 8mm wires). Check your fuel pressure. Next on the list is check for leaks on the intake tube and go to 4crawler's site to check the AFM and TPS. Both of wich can cause your symptoms. Last but not least is burp your cooling system. Air pockets in these 22re's can reek havoc on your idle and performance. Good luck chime in later to let us know what you came up with. Also what gears and tires are you running? if it's mismatched gears and tire size that is a major problem there. I currently run 4.10's with 31x10.50's and next week will be upgradeing to 4.88's and 33x12.50's. It might not affect your idle but will kill your performance.

Tracey98277

YES. vacuum leaks killed my re-build till i figured them out, other than that, adv. spark about 5 degrees (no more than 8) for a longer duration cam.

bwiygul

thanks guys, i'll check on the vac leaks again, how do you do the burp? and i'm running 245's, nothing big but it's my daily right now and i didn't want to regear till i get another car or truck for my daily. i also have manual hubs. thanks for the help and i'll let you know.

mightymouse

iTrader: (6)

To burp the system put the front end on ramps or jack stands. Remove the rad. cap (when engine is cold). Start the truck, turn on the heat, start squeezing hoses at the top and burp it! Air will move to the highest point. 245's shouldn't be that bad with stock 4.10 4.11 or 4.56's. Like i said i'm running 31's with stock 4.10's and there's plenty of giddy up.