Not so good first pass on 105 tune

SBCNX20

Junior Member
Aug 7, 2006
354
0
16
53
Central MA
So I leave work early Friday so I can rush to the track (85 miles), for what feels like (on the street anyways) my first solid 13 second run. Temp 73 at a 90' above sealevel track, baro's reading 14.6 sounds great so far right? Ummm NOT Truck left alright felt alright shifted 3-4 yum somethings not right at half track felt slower top of 4th layover begins 4-5 blah falls on face ............... 14.59 @ ARE YOU READY 89 big ones! So I look at my Log and fuel drops to 9600ish when it happens, now i run to the parts store 15 miles get fuel filter (45mins) after they find it! Its now nine o'lock and time for the 1 1/2 hr drive home!! FUN!! Guess its time for shim and lift pump! Funny thing is I made 10 street runs this week no problems-go to the track and SLOW motion!
 

95geo

Junior Member
Aug 8, 2006
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0
0
i was having the EXACT same problem, the valve opens and doesnt shit until you return to idle for a few. the shim mod fixed it (i did .049"), it was very consistant after, i just put the lift pump on too and it helps quite a bit, harder pull down low, in the middle and up top too. smokes a bit more also. i got the best of an srt-4, a t/a ws6 and a 2000ish camaro last night, from a dig until about 70 :D
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
SBCNX20 said:
What does this sound like to you Pat? It did the same thing 3weeks ago with PPE hot

Need to data log it to find out why it's laying down. Normally the 105 rips in 5th gear. On a really bad day, Blue ran 14.0 @ 98 on it, but that was just very poor air.

You might do the "bottle test" also to see if your PRV is popping.

But without data, it's hard to figure why it's doing it.

Log:

RPM
Throttle Position
Speed
Desired rail pressure
Actual rail pressure
Vane position
Boost sensor voltage (I trust this more than "boost" PIDs)
Main fuel shot duration
Timing
 

sweetdiesel

That's better
Aug 6, 2006
10,390
0
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52
Thailand
i have the 105 in, it pulls real hard in 4-5th so hard that i have to learn how to drive again pulled out to pass on the highway the other day,stepped on the throttle and just about ran into the ass end of the guy in front of me
i love this tune just have to pull out a little sooner:D