rack plug install now grey smoke

Sabbath5.9

Sabbath5.9

Neato niceo airplane glue
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Jan 16, 2008
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ok so i just installed a rack plug on my truck ( what a difference ) , now. before the plug. at WOT i would have a small black haze. now i have a greyish smoke until i spool all the way and then its a steady stream of black. now i have the 35/40 upgrade coming. will this help any? or what can i do to burn all this fuel
 
are you an auto or a stick? the hybrid will help. a GOOD afc tune, as well as maybe putting a plate back in might help...
 
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im auto, im not sure if i should change the exhaust housing to
 
mine is doing the same . the smoke has a greyish tint to it . but if im locked up in third gear and mash on it the smoke is thick black and puts out the fire until the turbo is fully spooled.
 
:pop: Interested in what you guys come up with for a solution. Been thinking this is going to be my next Mod and still have the HX-35 too. Did you grind the case or move the pump?
 
Rack plugs add "late fuel" so to speak. Since timing is fixed on a P7100 pump, injection always starts at the same time. As the AFC moves and the rack advances and turns the plungers in the pump, it adds more and more "pulse width" or injection duration. A rack plug allows the rack to travel that last few mm's, so it adds even more late fuel. While I can't personally examine your truck, I'm guessing the late fuel is leaving a little raw fuel in the exhaust stream and causing the abnormal color.


In short, if you set your timing higher than 16*, more like 18-20*, you will probably fix the gray-half-burned raw fuel smoke and you'll have straight black smoke. Plus, a little more timing will add a little horsepower as an added benefit.
 
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Tpull123 said:
:pop: Interested in what you guys come up with for a solution. Been thinking this is going to be my next Mod and still have the HX-35 too. Did you grind the case or move the pump?
Click to expand...

i grinded the case , just be careful the case will get thin . before the 2095 plug i was making 35-36 psi now after it made 42-43 psi . def worth the 15 bucks for it !
 
i was thinking it may be slipped timing on my truck , because im running stock timing , but if sabbath is already at 16 degress it has me wondering .....
 
Ok, Yea I was thinking of trying to grind a little bit, then clean the shavings off good, then seeing if I could slide the pump back enough without popping the timing gear loose to get the plug out.

If I can get about 0.1-0.15" movement out of the pump, thats that much less material removed from the case. Obviously the down side is if I slide the pump back and I didnt grind enough, I have to slide the pump back on, Grind more, and repeat. Wish I would of had one when I was setting the timing, but Hindsight is always 20/20 though.

What kind of power and EGT's you seeing? I am a little concerned since I have 5x12 injectors as well.
 
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The timing case has a molded recess right behind the rack plug. Just grind till you get flush with the recess and you'll have sufficient room to replace the stock rack plug with 0% chance of grinding too far/deep.
 
Big Blue24 said:
The timing case has a molded recess right behind the rack plug. Just grind till you get flush with the recess and you'll have sufficient room to replace the stock rack plug with 0% chance of grinding too far/deep.
Click to expand...


First Time I have seen someone comment on how deep to grind, thanks!!:Cheer:
 
i have a 1600 degree egt gauge and i can peg it easy , a tighter afc sping should help control the smoke and heat wont rise as quickly and im still on stock timming so thats not helping.
 
As I suspected, I dont have a guage yet because my truck is just in the finishing up stages and has only ran for a couple of minutes at a time and not hard at all yet. I plan to have the gauge in place before it makes its first real road trip and would like to get it on the dyno as well.

This upcoming weekend I want to do the AFC Mods, tight up the AFC spring, and turn the smoke screw in a turn roughly.
 
well im hoping that the 60mm wheel is going to help. once i do studs im going to problay do 20 degree timing. and i havent got on my truck all the way yet. tommorow ill know what its going to do. i pegged my 1600* gauge instantly so im sure its alot hotter now. 2 more days till turbo parts get here
 
Veryyyyyy interesting. I ran a 15.1 at 95.7mph, I defueled and ran outta rpms every shift. 1st and 2nd gear was a nice stream of smoke then 2nd to 3rd gear, that's when I lost all my fueling until overdrive
 
What do you have for a lift pump setup? New filter, cleaned bowl and preheater? Stock overflow valve?
 
Stock lift pump, new filter, and stretched spring in the overflow valve
 
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