So last night I rebuilt my turbo with the simple $77 rebuild kit. The reason was because I am chasing an oil consumption issue. About 1 quart/1000 miles. Not injector o-rings and I couldn't really see anything that looked too promising for an oil leak in the turbo last night. Well today I spooled it up to 32 PSI! I don't know if that is too good for it but she held up today at that. Curious to see like what a safe boost PSI would be. Any thoughts?

Also today now that I finally got the right adapter so I can check fuel pressure, I decided to hook a temporary gauge up too it. Well it idles at about 64 PSI, running at 65 mph it runs 62 PSI, & at WOT it drops to a low of 52 PSI. I do not think any of this looked too bad. The only question I have is bleed down time when the fuel pump shuts down like while I am waiting for the WTS light. There is a video of the fuel pressure gauge and tach so you can see when I shut it down. I also turned the key back on and waited for the pump to shut off. You can see that the fuel pressure bleed down seems quite quick to me. Is there a check valve that could be getting weak?
Fuel Pressure Video by robinsonpowerstroke | Photobucket

 

I have a brand new pump and mine drops faster than that (sensor after filter, FRx installed). I have the same pressure when running. I'd like to know if I should be worried about the bleed-down.

Stock sticks and turbo, DP tuned:

 

Well my sticks are only about 5000 miles on them.

 

So if yours drops faster, I wonder if there is a way to bump up the time the pump is on during the WTS period so it basically never shuts off.

 

I couldn't see your video but fuel pressure drops to zero within seconds after the pump is turned off.

 

No it drops from 64 PSI to 20 PSI in about 18 seconds.

 

My boost information was on the original stock configuration (old sticks). I have since replaced the cups, the injectors (Stage II), the turbo (38R), billet intake plenums, CAC boots/clamps, and tuner. I may as well have bought a different truck.

That's three that lose FP quickly when the pump times out... good enough for me. As soon as you turn the key to start, the pump jumps right back up.

 

Wonder what the difference in bleed down time might be between a Frx modded truck... and stock?

 

Mine bleeds down instantaneously. As soon as the pump turns off, it goes back to zero. As it should, unless the screens in the mixing chamber are SUPER clogged (if measuring prefilter) or the fuel filter up top is clogged (measuring post filter). Right? Keep in mind it's open to atmosphere in the tank.

As far as boost, I've always heard stock turbo will hold up to 30psi. Anything higher and the pressure differential is too much. Now supposedly the DS billet wheel (WW2) is producing less pressure differential and can go higher, but who really knows?

The 30 psi should be measured at the turbo outlet, so if you're measuring at the map line or the AIH delete, might subtract 2-3 psi from that.

 

Something else to mention is that gauges behave differently. I know isspros can be programmed how to respond. Might be that the needle has a slow response. I can't see the video on mobile though for some reason.

 

Seems like in Bill's writeup... he was able to achieve 43psi with an "acceptable" backpressure.
Havent heard to much more expounding on that tho...

 

IDK. Curious to know.

 

Ya that is a good point. My boost gauge is a mechanical Autometer gauge so it reacts very fast.

 

My FRx-equipped truck bleeds the pressure down real fast... much faster than the vid above (with a dead-head).

My ISSPRO EV2 gauge is programmed to react quickly. It showed "dips" in my boost when I had a boost leak on the passenger-side intake plenum.

 

Rich, did you have the OCR in place when you had that 30+psi boost reading? Just wondering if the DP tuning takes care of PCM defueling, or if it still needs the OCR hardware.