ACCOBRA

I have a 2007 L92 engine. My rev limit is 3800 rpm. I obviously have problems with the VSS.
I use an inductive speed sensor with two wires. What kind of speed sensor works with the ECM? Any suggestions?

Doubledip

They use 2 wire inductive.... Why do you think it's a speed cut. ... Sounds like rev limit cut. How did you get tune in there. Was it a manual tune flashed in or did it start as an auto tune


Have seen auto tunes limit at around 4000rpm no matter what you do to the rpm limits

Post tune and we can look at it for you

ACCOBRA

I don't have the ecuipment to post the tune:/
The company that made the setup (harness package) said that if I don't connect the VVS I will have problems with higher revs. See quote below;

"I did notice that without a VSS input there is a 3800-4000 rpm rev limiter that I don't have a way of shutting off. You will need to make sure the VSS sensor is hooked up and working properly for the engine to rev higher."

I have the VSS connected but I still have problems with the rev cut at 3800rpm. No matter how I twist and turn the cabels, since my speedometer works the ECM gets a signal...

Doubledip

seems strange considering I have built a heap of looms running the E38 computer and they have been fitted to boats with no VSS and they rev to 6800rpm all day long

ACCOBRA

I think so to! If I rev the engine when standing still it still cuts the rev at 3800rpm!

ACCOBRA

What else could cause a rev cut at 3800 rpm?

cam

iTrader: (9)

Im having the exact same issue with my L92 swap did you ever get this figured out?

Doubledip

Post your tune and I can take a look

cam

iTrader: (9)

Im pretty sure its VSS related. For some reason the PCM does not accept signal from my t56. I know the signal is fine as my autometer speedo is working fine but when I scan and drive it the scanner speedo stays at zero. I tried setting the fuel cut offs in park/neutral to 6900 as I have read some boat guys run these engines fine without VSS input so I figured what the heck? But still nada. I have the VSS wired to pins 71+72 x1 conn.

Unnfortunately I cannot attach my tune file here I tried but its too big. Can you PM me your email address and I'll send it to you?

MontecarloDrag

iTrader: (3)

Most calibrations have a Bad-Vss fuel cutoff, which may be much lower than normal limiter. On these calibrations you rise that value to match your normal limiter and you're set.

In the 2007 L92 file I have I see no Bad-Vss limiter, only a Park-Neutral limiter of 4000 RPM, this may be it.

cam

iTrader: (9)

Where do you see the park neutral limiter? I poured over the file a few times and didnt see it anywhere? Sounds promising

MontecarloDrag

iTrader: (3)

In HP Tuners go to Fuel tab, then Cutoff, DFCO Tab
Open the Cutoff RPM vs. Gear table (normal)
It is a table from 1st to 6th gear plus Park, neutral and Reverse. Each has a cutoff RPM limiter. In the stock calibration I have, both neutral and park are set to 4000

ACCOBRA

i sent my computer to speartech and they fixed it. I dont know what they did. I run my car on bench dyno last month and i had 463ps with a stock L92 . Still got an issue with error codes both fuel bank lean though.

cam

iTrader: (9)

Good news it was tune related. Chris at HP fixed it for me and will be adding the fix to the new default torque tables so keep your eyes open for a new update for anyone interested in this.

No speedo pegging either

Old Geezer

iTrader: (3)

And, the fix is??

cam

iTrader: (9)

A quote from Chris

fastgmc98

iTrader: (15)

I'm having the same problem on a (2) 2007 5.3(E38) and a (1)2008 6.0(E38) all 3 vehicles have TH350 transmission's and I set the rev limiter everywhere I could see a rev limiter function to 8,000RPM's but they all still rev limit at 5,500RPM....
I used EFI Live on these conversion's

fastgmc98

iTrader: (15)

Anyone???
Or do I need to use HP Tuners to access tables not available in EFI Live...

cam

iTrader: (9)

Im unfamiliar with efiLive but did you remove all torque management? If not Id start there that was my issue in the end

fastgmc98

iTrader: (15)

Yes, removed all torque management and set every rev limit function I could find to 8,000RPM's but nothing, they all still rev limit at 5,500 RPM's...

All 3 motor swaps/conversion's are using GM TH350 transmission's...