[Carl Donica]

After intalling a new autometer boost gage, I started the engine and ran it up through about 2100 rpm. Wasnt expecting a lot but maybe the gage would at least wiggle. It didnt. Short drive down county road, no movement. Back in the shop for troubleshoot, removed the tube from its fitting in the side of the intake( a few inches behind center where a threaded plug was), there was vacuum at idle and the vacuum increased with rpm. I disonnected the boost tube from the intake to the fuel pump and had the same condition here. I know the engine isnt loaded but shouldnt it at least produce zero atmosphere? The gage does indicate some boost: 2nd gear full throttle, 4 lbs. 3rd gear full throttle, 8 lbs. 4th gear full throttle uphill only 14 lbs. 5th gear 65mph cruise ( around 1775 rpm) is less than 2lbs indicated.Seems kinda low to me from other posts that I have read. All comments welcome, suggestions too please.
Thanks, Carl

 

[mooktank]

Check for leaks in the intake piping. What's your turbo and fuel setup?

 

[Carl Donica]

Stock h1c, I assume 16cm housing(GM setup). Fuel rate delivery has been adjusted some but not maxed out and star wheel has been adjusted.
This truck is heavy and poor aerodinamics so I figure these were low. Wanted to do the 12cm turbine housing but if there is a prob with the turbo already...
Carl

1979 F-250 crew cab 4 x 4
4 bta
ZF S-42 5 speed
Borg Warner 1356 x-case
Dana 60 rear
Dana 44 front
3.55 gears
255/85R16 tires (33.5x10.5)
Hydroboost steering and brakes
Custom 40 gal. fuel tank
Much more later

 

[matt2matt2]

I have not hooked up a vaccum gauge to mine, but with my engine all stock and still sitting in the stepvan it puts out about the same in boost. The max I have gotten is 13lbs. I can watch the boost gauge react the same as when I hear the turbo spool up. I can also tell when the governer spring is defueling as the boost drops to almost nothing at top speed. I'll hook up a tempory vaccum gauge tomorrow and see it it reads anything like yours.