My dads truck would idle rough and have reduced power. I put in a new FCA and all is good.

 

I just put in a arson III kit that included a new fca and results were the same

 

Well, that being the case. Assuming that RP is good(I don't see a RP gauge) then I'm with the first couple of guys. I'd go back to the Turbo/Wg. Never heard of D-Tech turbo's. Sory, I'm not at all familiar with ther '03 WG setup, but did you try wireing the WG shut, so it can't move? Maybe your drive press is blowing it open?

 

Yes I did try that, I switched turbos out last week to a he351 with the wastegate disabled same thing happened. With the waste gate it was 18 psi without 30. Im changing intercooler boots this week. Ive pressure tested everything and sprayed down with soapy water and have been unable to find anything but I have had large leaks before and they were so big the soapy water trick did not work. The only reason I found it is that I ran my hand around it and felt the air coming out. If it was a fuel issue I dont think I would have that big of improvement from blocking off the wastegate.

 

Grid heater, & gskts? How about the intake man. plate? Most just pull off the boot, & plug the hose to test the aftercooler, etc. It may be a crack in the grid heater housing, or the intake manifold plate, or even the head on the intake side. Probably wouldn't show any signs of leakage either, & hard to test. But you could loosten all the int. valves to make sure they are closed, & plug a cyl. leakdown tester into the intake , & listen, & feel for leaks around the head, etc.

 

will it hold pressure if you put 10 psi in it or do you just keep the air flowing to it? Maybe valves? I had a leak between the manifold and turbo before that blew the gasket out behind where you couldn't see toward the motor and it wouldn't spool right. But you said you changed turbos so u would of seen that. Did you take the manifold off and check the gaskets? Again just guessing.. .Good Luck

 

Right now guessing is what is going to fix it diagnostics is not helping at this point. I will be out of town for a while and when I get back I will tear the exhaust manifold off and check it out. That is the only part I can think off that has not been thoroughly checked out.

 

Have you checked it with a 2nd gage? I had the same thing happen with oil pressure once, changed everything in the car, the gage was reading low.

Joe

 

I had a edge with attitude on before and the readings were close to the same. When I put pressure to it on the pressure test it will bleed off to nothing so I know it going somewhere just cant figure out where.

 

If you dont have a RP gauge get one. Im thinking you are pulling down your RP and having the loss of boost/power.

 

I will invest in one whats another couple hundred at this point.

 

Took all boost intercooler tubes out when I put new boots on and the everything looked good. Put back together and it is still doing it. Im going to reverify the fuel pressure again.

 

I think I found it. I did yet another boost leak and took the valve cover off backed off the valves as suggested and had a lot of air coming up through the head. I must have a bad valve. Im going to look into my options.