turbo tune help

[AKCOLLIN]

Hello
Fairly new to tuning but getting the grasp of things. Main problem i am having is, truck will not build boost and read it on my scanner. Truck runs decent and it drivable, but will only pull about 3200 RPMs and starts cutting out like a rev limiter. It will not read above 105 KPA. I don't believe this is a mechanical issue, but more of a fail safe in ECM. I uploaded my tune file & a log file. Also truck idles at 70-75 KPA which is strange. Ive been beating myself up on this problem all summer thinking i was getting bad MAP sensors.

1999 4.8LS with P01 ECM running on 2 bar OS (VE Tune)
Engine installed in 79 C10 W/ Turbo 400
2" hotside 7875vs racing next gen cast, 4" down pipe
Deka 80s
Cam BTR truck stage 4 224/230-109lsa .553 lift / LS6 springs
Walbro 450 in tank with aero motive regulator
EFI solutions truck style 3 bar MAP sensor

Thanks

[5FDP]

1 bar MAP channels only read to 1 bar, so that is why it stops reporting data at 105kpa. Remove that channel and replace it with the 3 bar channel.

Go through all the DTC codes and disable all the transmission related codes. Also disable the abuse mode in the engine and transmission tab, set it to 7,000rpm and 0mph in the engine tab.


Zero out the EGR spark correction table too.


Something seems off with that MAP sensor. If you have the stock MAP still just change the data back and plug that sensor in, see if the idle reads any different.

What is your fueling like under boost? Is it too rich or lean??

What is your spark plug gap?

[AKCOLLIN]

Spark Plugs TR6 gap .025
ill zero out those tables and give it a shot.
i havent been able to build boost.

1 bar MAP channels only read to 1 bar, so that is why it stops reporting data at 105kpa. Remove that channel and replace it with the 3 bar channel.

Go through all the DTC codes and disable all the transmission related codes. Also disable the abuse mode in the engine and transmission tab, set it to 7,000rpm and 0mph in the engine tab.


Zero out the EGR spark correction table too.


Something seems off with that MAP sensor. If you have the stock MAP still just change the data back and plug that sensor in, see if the idle reads any different.

What is your fueling like under boost? Is it too rich or lean??

What is your spark plug gap?

[5FDP]

Other than some of those changes I don't see anything stopping it from making boost. Other than it blowing out the spark of it's way to rich/lean.

All the rev limiters are over 5,500rpm, still likely way to low for how high those 4.8's can rev with a camshaft like that. You could see 6,500rpm easy on an engine like this.

But the rods will exit the block or bend if you get too carried away and go over 500-550whp.

[AKCOLLIN]

Figured it out!!
i was logging only 1 bar map.

Thanks for the help. now time to fix the VE table.

Thanks again