My 95 F350 7.3 will not open up the turbo is ok runs fine just takes for ever to open up

HI Derek.

There are a few possibilities that come to mind.
3K RPM is generally about the break-even point for when Turbo boost would kick in. There is a dump valve on the turbo system that opens up and vents the extra turbo pressure under high-rpm situations where the boost isn't needed - say high but steady speed on a freeway. If the dump valve system is malfunctioning, then that anticipated turbo run-up in power won't happen.

Revving fine when in neutral may not tell you much, other than that the engine can rev. The gating system will (or should) run differently under load - whether climbing a hill or accelerating, this is where you want the turbo boost to give you the extra power. THat's where the exhaust gate should stay shut, or mostly shut, to allow the turbo to force more air into the pistons.

You might want to check whether the APC (Automatic Performance Control) for the turbo has a separate fuse. (The name might be different on your model, I'm remembering from my 80s/90s era Saabs). If the fuse is blown, that could also lead to lame performance, especially as I'd imagine that the system would be built to fail or go to full open if the APC fails or loses power - that'd keep people from having run-away power that they can't manage.

Hoping this helps

D

Are you using the engine computer from the 90 or the 95 car?

Chek the if the fan works with direct power from battery,if ok check or change fan resistence(fan control)!

The most common cause is due to a proper tune up.Plugs,wires,gas filter,air filter and if all is well on that aspect of the engine I would change the EGR valve due to fuel mixture and advance control due to turbo.........Hope this helps you out.

Yes, replacement can be pricey. The engine is de tuned to allow for the pressure of the turbo, so without one you will not have much performance.

Have you had your mass air meter checked or replaced? This is the unit attached to the air intake hose behind your air filter. It senses the air temperature, speed, density, etc... and adjusts the fuel/air ratio to keep the vehicle running at "peak" performance. Also, check your TPS (throttle positioning sensor) it can also cause the problem you speak of. The TPS adjusts your engine speed/idle etc. and also compensates for hot/cold changes etc. This is roughly a $35.00 part and in most cases usually an easy fix.

IT COULD BE ONE OF THE FOLLOWING:

1.)36 (turbo) Wastegate control circuit open or shorted

2.)36 (3.9/5.2 RWD) solenoid coil circuit (air switching)

3.)36 (Turbo IV) #3 Vent Solenoid open/short

I HOPE THIS HELPS.

The smoke is obviously a big indicator you have oil in the combustion chamber. On turbo motors it is likely coming from a leaking oil seal in the turbo housing itself. But there is a possibility of internal damage like a piston. Might want to run a compression test to eliminate any internal engine issues first, then focus back on the turbo oil seals.

check for boost leaks or a blown boot.

Have you checked compression on non firing cylinders? Likely has blown head gasket between these two cylinders if located side by side.