4.8 turbo LS swap getting minus timing....help

[wrenchin24]

Just getting near the end of my 4.8 swap in a 87 fox body and running into problems getting any power off idle. Car starts and idles fine but as soon as you hit the throttle it falls on its face and backs the timing way off. At idle timing is -5 and as soon as you accelerate it drops to minus 15 off the throttle and it goes to +2 and back to -5. Checked for knock and it reports 0. AFR is 14-15.5 at idle and goes to 12 under throttle and a bit of boost. The engine transmission and ECU are out of a 2005 Savanna. heads and cam are from a LS6 and 80lb fuel injectors. Im running a SD tune and using a 3 bar map. The base tune I have is from a guy who has used it on all his builds and many of his friends builds with very similar specs and no problems. Anyone have any idea what is going on here. Thanks in adance.

[DSteck]

Need the tune and a data log.

[wrenchin24]

feb 9 2014.hpt

[wrenchin24]

table.jpg


A quick snap before my laptop died. the car has no power under load.

[VodeAn]

Okay looking at your tune for about 60 seconds I think you should make a few changes, and looking at that picture from the log I can see where your problem is coming from.

First,
Your timing being pulled is a direct result of the "Max Spark Retard Limit vs. RPM" table.
Compare that table to the timing that is being pulled and you'll see a direct correlation.
Don't just zero this table out, see below.

Second,
It looks like someone tried to disable the knock sensors.

Third,
Whoever disabled the knock sensors didn't do a very good job. Some tables are zeroed out, some aren't, some should be, others shouldn't.
So, you have options. Copy the vales from a stock pcm back in the knock sensor tables=, and see if the problem is fixed.
Or, properly delete the knock sensors, physically and in the calibration. (I don't recommend this)

Fourth,
Your PE delay is set to 5,500 RPM. Set it to zero.

Fifth,
Your cold PE TPS enable table is set to 100% and your hot is set to 50%.
Looking at all of your PE enablers if your into it at part throttle there my be an earth-shattering kaboom.
Read all of this thread for more information on tuning PE http://www.hptuners.com/forum/showth...PE-Table-Usage

Sixth,
Your high and low octane tables are equal, which makes sense for having the knock sensors tuned out.
Depending on what you do about the knock sensor tables you will probably need to add some wiggle room in there.

It took longer for me to type this than to find those issues. My point here being that there are probably MANY other things that are off.
I hope you didn't pay for that baseline tune, and you might want to tell the other 3 people who have the same or similar tune so they can have a look at their own stuff.

Good luck, if you have other questions please ask, I won't tune your car for free but hopefully we (me, other forum members) can get you going in the right direction.

[wrenchin24]

my hp tuners dosnt show a PE delay option in the fuel table. I looked everywhere for it and cannot find the 3values to adjust. am I missing somthing here? thanks for the reply

[VodeAn]

Are you running the latest build?

[VodeAn]

Take a screenshot of your computer with the pe tab open.

[wrenchin24]

20140217_175605.jpg

[5FDP]

Click EDIT > VIEW > ADVANCED

You are viewing "basic" mode, TONS and TONS of stuff you arent seeing.

[wrenchin24]

ethanks

[wrenchin24]

no kidding on the missing tables... now to figure out which ones to change.. im going cross eyed just looking at it.