how much boost should i be seeing stock on a 94 1 1/4 ton truck today had no power, tons of black smoke vac lines where both broke off, i fixed it, and took it out for a ride. made good power, PSI PID was 27lbs(no boost is 14 lbs, atmospheric pressure) under max load. 13lbs sounds high? after 13 lbs the truck would suddenly loose all boost, power and loose cars behind it in the smoke show it was putting out. it was like the wastgate was fully openeing, and not just trying to maintain max boost. put a wastegate controller on it then, and then only had max boost of 21(7lbs) but it did not do the smoke show.
7 souds about right for a completely stock truck, should be 5-7 sustained depending on condition. If you stab the throttle hard at about 2000 rpm's with the converter unlocked, it should spike up to 10-12(sometimes as much as 15), but cut back immediately to about 5-6 as the computer reads the overboost and compensates for it.
just call me mr 6.5L this week, have had 3 apart, had two turbos off, and now one head off. this one today is gonna need major work. bent pushrod, bent valve, piston contact, and the rocker bridge is cracked.
semilar question here. I have a 5 spd. and some times under load, i can lay into it in 4th gear around 40mph (1800rpm) and no boost is created. seems like when i need it, it isnt there, but then once i get out of town 55mph 5th gear 1600rpm it will create boost no problem. BUT it maxes out around 4psi (will be getting a controller next week) ... my question is, do you think the vac. pump is going out? or is the engine compartment just getting to hot and air isnt being compressed enough to create boost? if the vac. pump is going out. will it ever tie up? or will it just not create vac.? dont want to have to take it off if i dont have to. Thanks in advace guys!
