I bought a 2000 F250 PSD about a month ago (traded a '95 F250 PSD), and it felt sluggish. I installed boost/pyro gauges and started working on things. After fixing an intake boot leak, I was getting 10lbs max boost on level ground empty in 4th/5th gear. I checked/cleaned all the intake boots, the gauge is working properly. I cleaned the EBP tube, and the EBPV is working properly. I found leaks in the up-pipes to the turbo, and replaced the tubes and gaskets. I installed a fuel pressure gauge and am getting 57 PSI at idle. After everything, I'm still getting 10-11 lbs boost max. With the wastegate actuator disconnected I get 15-17lbs. I'm looking for ideas on where to go next??

Wastegate actuator/spring?
Fuel pump?
MAP sensor?

 

Hmmm, I assume there is no dust damage to the turbo. Do you have a way of measuring fuel pressure at WOT? And under heavy load like a long steep hill? Or going out on the freeway and getting up to speed, 3000 rpm and holding the throttle to the floor and controlling the trucks ground speed with the brakes for a couple hundred yards? If it drops off you've found your problem. If it still holds I would guess that you are on the right track with a bad MAP.

 

I do have a new fuel pump, I may just install it to see if anything changes. If not, I know I have a good spare... I don't have an easy way to check FP when driving (the gauge is under the hood...) It's possible the turbo is dusted there was some dust in the intake when I bought it. I did your filter mod w/ the NAPA filter right after I bought it. What's interesting to me is it stops dead at 10lbs of boost w/ the wastegate actuator hooked up, but pretty easily pulls 15-16 with it disconnected. It's like its dumping early...

 

Try removing the line going to your boost sensor and capping the line. Maybe the sensor is going south...

Max

 

Yeah, what Max just said, if it stops dead at 10 connected there's a problem in the boost control. I've removed the hose from my control valve and capped it off. Plus I removed the plunger from the wastegate lever and tightened up the spring tension about 5 turns. Lot's of guys here just crank it down to the bottom and very easily get 30+ lb of boost running chips and propane, etc. From what I have read here on the board you can get around 17 psi boost with stock programming.
When you get the 16 psi of boost is the power there too or is it still sluggish?

 

Do you mean the MAP sensor or the wastegate actuator line? I have the wastegate actuator line off and plugged at the moment and it'll pull 16lbs of boost, and makes good power. Or is there another "boost sensor"??

 

If you've got the actuator line off and the truck makes good power and doesn't defuel, then I would think that the wastegate solenoid (the small grey plastic thingy that the actuator line from the turbo runs to) is getting a false signal or is malfunctioning causing the wastgate to open. This line can be left disconnected. If I understand this correctly, the map sensor actually reads boost pressure and sends the signal to the computer which in turn controls multiple functions. The vehicle will not operate correctly with the map sensor disconnected. I apologize, my wording earlier was not very accurate. Hope it helps.

Max

 

So... did you replace the map sensor? What's the fix? Mine is low as well... even with the disconnect I'm only getting up to 14-15

 

That's not much below "normal" for a stock rig. You can adjust the length of the actuator rod (shorten it) to apply more seat pressure to the wastegate. That will hold it closed a little bit longer and bring the boost up.

 

Thats exactly what i did last week. I gained about 4-5lbs of boost.Now, with the wategate unplugged,the 6637 filter and straight exhaust with factory tune i get 24lbs of boost pulling my boat. Before i shortened my rod I could reach back there and the rod was sloppy and loose, after i adjusted it now its tight, you cant even wiggle it.Might be worth checking.!

 

How do you shorten it? is it adjustable, or just bend it?

 

yeah, I havent looked yet, but how do you tighten it?

 

You can either take the little snap ring off the linkage or do what i did and take the 2 10mm nuts off the canister, then break the locknut and turn the rod in, towards the linkage\lever. i used a little baby set of vise grips to grip the rod and turn it in,, The tighter the better.