No pre-boost screw - Competition Diesel.Com

drmisherre · 07-29-2012, 10:15 PM

I was trying to turn down the screw and it pulled threads out, would that be housing? So I'm currently not running the pre boost screw, am I hurting anything until I fix it? If I'm understanding the tuning pages currectly, I'm running the least amount of pre boost fueling currently am I? Im still getting a decent amount of smoke and 50-100% throttle before the turbo kicks in. My mods are: 
94 p7100 12v 
hx35 turbo 
90hp injectors from ********** 
18* timing 
Afc mods 
Grinded flat fuel plate 
Fuel plate moved forward all the way 
 
Can't remember what else I've done to it but thats most of it. It runs alot better now without the screw in. Before I took it out, it would max out at 25ish lbs of boost, now I'm easily seeing 30-35lbs. Also, I welded my wastegate closed. 
 
Do I need to mess with the starwheel more or with my mods, is my smoke just the nature of the beast? 
 
Thanks guys!

Olee Poole · 07-29-2012, 10:35 PM

With the screw out you will have a boost leak.. Boost is built on the side to move AFC arm thats why you are seeing more smoke down low.

drmisherre · 07-30-2012, 04:21 AM

I'm still seeing less now though with the screw out. I'll try and get something at least put in there.

burnin oil · 07-30-2012, 08:10 AM

I stripped the screw out of an AFC myself. I pulled it off the truck, cleaned the hole up, tapped 1 size larger and installed a bigger diameter screw. Problem solved. When I lost mine the truck was actually a little cleaner running other than a puff off idle. I needed just a little more fuel to light the turbo but it was close. Good luck.

Hurley · 07-30-2012, 09:21 AM

Quote:

Originally Posted by burnin oil

I stripped the screw out of an AFC myself. I pulled it off the truck, cleaned the hole up, tapped 1 size larger and installed a bigger diameter screw. Problem solved. When I lost mine the truck was actually a little cleaner running other than a puff off idle. I needed just a little more fuel to light the turbo but it was close. Good luck.

yes, simply because your boost reference is effectively 'lessened', causing it to not move the afc foot forward

07-29-2012, 10:15 PM	#1
drmisherre Name: drmisherre Title: Green Behind the Ears Status: Not Here Join Date: Jun 2009 Member`s Gallery Posts: 53	No pre-boost screw I was trying to turn down the screw and it pulled threads out, would that be housing? So I'm currently not running the pre boost screw, am I hurting anything until I fix it? If I'm understanding the tuning pages currectly, I'm running the least amount of pre boost fueling currently am I? Im still getting a decent amount of smoke and 50-100% throttle before the turbo kicks in. My mods are:<br /> 94 p7100 12v<br /> hx35 turbo<br /> 90hp injectors from *********<br /> 18 timing<br /> Afc mods<br /> Grinded flat fuel plate<br /> Fuel plate moved forward all the way<br /> <br /> Can't remember what else I've done to it but thats most of it. It runs alot better now without the screw in. Before I took it out, it would max out at 25ish lbs of boost, now I'm easily seeing 30-35lbs. Also, I welded my wastegate closed. <br /> <br /> Do I need to mess with the starwheel more or with my mods, is my smoke just the nature of the beast? <br /> <br /> Thanks guys!

07-29-2012, 10:35 PM	#2
Olee Poole Name: Olee Poole Title: Too Much Time Status: Not Here Join Date: Aug 2006 Location: Salisbury NC 28146 Member`s Gallery Posts: 1,046	With the screw out you will have a boost leak.. Boost is built on the side to move AFC arm thats why you are seeing more smoke down low. __________________ 2002 Quad Cab 4x4 auto, HTT 62/65-12, RV275s 1997 Reg. Cab 4x4 auto, II 62/65-12, 4k and DDP 2s. 1997 Reg. Cab 4x4 auto, 13mm pump, Hamilton 188/220, 64/71-13 over S480 project.

07-30-2012, 08:10 AM	#4
burnin oil Name: burnin oil Title: Diesel Enthusiast Status: Not Here Join Date: May 2008 Member`s Gallery Posts: 229	I stripped the screw out of an AFC myself. I pulled it off the truck, cleaned the hole up, tapped 1 size larger and installed a bigger diameter screw. Problem solved. When I lost mine the truck was actually a little cleaner running other than a puff off idle. I needed just a little more fuel to light the turbo but it was close. Good luck. __________________ 95 2500 4x4 G56 180 pumped 4k 362/475

07-30-2012, 04:21 AM	#3
drmisherre Name: drmisherre Title: Green Behind the Ears Status: Not Here Join Date: Jun 2009 Member`s Gallery Posts: 53	I'm still seeing less now though with the screw out. I'll try and get something at least put in there.