Well i put the boost gauge in tonight. Its an Isspro. At idle it sits at zero. normal acceleration about 5-7psi. hard in thrid 16-17psi. when I let off the throttle boost drops to zero. Does this sound right. I have the gauge on the dash for now so i can see what i get on the highway tomorrow. Do these #'s sound right for a stock truck? as far as I know nothing is turned up.

 

That sounds pretty normal to me. What year is your truck, auto/manual? They can vary in boost numbers from 14-20 or so stock depending on year and transmission (and other things, I'm sure).

 

Its a 93 w250 Manual.

 

Yep, then it sounds about right. I'm pretty sure the earlier non-IC trucks ran more boost stock, but for a 93 your numbers sound right on.

 

Zero at idle is right then? I'm ok with everything else. That was the only thing that didn't seem right too me. I figured so little bit 1-2 psi. I guess its time to start turning up the pump.

 

0 is perfectly normal for idle. You won't get boost unless the engine is loaded down somewhat. Even revving in neutral won't get you boost (unless you have a small turbine housing or retarded timing) because it isn't loading the engine.

 

my truck is a non intercooled truck and my guage is allso a isspro!
before the pump was turn up, the boost was 17-18. After pump turned up 22 and yes at idle our even at cruise with no load is 0.....ya i thought that there should be boost also but it is all normal!!!!