Looking for the flex fuel pin in a e40

[1meangto]

I have a idea on making somewhat of a custom OS. I have a few E40 gto's and a tbss that I've tuned and all have spray on them. I see that in the E40 calibrations list under general spark flex fuel(ethanol) spark (b5114). Now if you put in say -5* in this table and could power the pin that detects ethanol it should pull that amount of timing from the total timing. Does anyone know if this would work?

[GMPX]

It will be a little more complex than that because it will alter the fueling too. Good idea though, might be pretty tough to get working.

Cheers,
Ross

[1meangto]

Are the flex fuel fueling tables available in efilive? I looked for them but may have over looked them. If so couldn't you just 0 out the fuel table? or set it to 1.0? I have never sen a flex fuel tune so not sure what they look like. But anyways I would assume you could just put a smaller jet in the fuel sided to accommodate the richer condition. Every car I tune I tune for e85 anyways it would be nice to make the flex fuel program work if possible. The last car I tuned on e85 thats been dyno'd picked up 28 rwhp and 33rwtq which is a pretty good gain just to run cheaper fuel.

[1meangto]

GMPX- do you have a pin layout for the e40? I really want to try this at least for the e85 tune I have in her car now. It would be great to switch back and forth.

[LSxPwrdZ]

Bumping this back up... any progress on this?

[GMPX]

Not even been looked at.

[gmh308]

:) :)

[swingtan]

Have you opened your E40 tune to see what's in there? I just looked at one with OS 12598977 and found the following.....

{B3671} Stoichiometric AFR: has ethanol range from 0.0% to 100%

{B5114} Flex Fuel (Ethanol) Spark: Spark table for Ethanol fuel.
{B5115} Flex Fuel (Ethanol) Spark Mixture Spark Correction: AFR vs spark timing correction for ethanol.
{B5145} Flex Fuel (Ethanol) Spark Multiplier:For blending between ULP and Ethanol fuel.

So if you were to send the appropriate signal to the Ethanol sensor pin, you could force the ECM to use the Ethanol tables for NOS. If you did this right, you can use the E40 to control both spark and fuel when running the gas.

FWIW, the Ethanol sensor signal is a square wave with the frequency indicating the ethanol percentage, it's not just "power on for ULP, power off for Ethanol". However, it's easy enough to make up a square wave generator to switch between the required frequencies. I'd use the NOS solenoid power to trigger the change.

Finally, before you ask, no I don't have the pin outs for the E40.

Simon.

[LSxPwrdZ]

I saw the same thing and mainly bought EFILive for the extra tables not available in my other software. I'm sponsoring a ZR1 currently that is on the heels for the record of being the fastest ZR1 on the planet and it will have a COS from EFILive powering it in two weeks.

With that said I also do a lot of LS2 GTO's and some of those guys like to spray their cars as well and it'd be nice to have an option to do the same we are doing on the E38/67 ECM's.

[ScarabEpic22]

I agree, but I highly doubt the E40 will be revisited except for a bug fix or error in a calibration. What really sucks is that it was only used for 2 years then GM moved on, I think you're going to have to keep doing the relay on the IAT sensor and use that to pull timing.

[Tre-Cool]

Bumping this thread and posting that the flex fuel pin is pin 4 on the bottom connector on the E40.

Again, Pin 4, C3

[Highlander]

Relay on IAT works rather well.. you could use our LPE Signal generator/switcher for E85 pin. Works rather well.

[Highlander]

If there was enough interest I could do a nitrous custom OS for this.

[Tre-Cool]

So i installed a flex fuel sensor on an e40, turned the switch on and set dtc fault codes and everything worked as expected.

the only thing I needed to take into consideration is we are missing a couple of extra tables inputs for transition between percentage changes, if you install the sensor close to the fuel pump it's probably not much of a concern. but on this particular car i installed the sensor on the outlet of the rail before the reg & with the default transition values it took some time before the ecu started compensating for the ethanol change.

In the end i just chewed up a credit with my hpt cable to zero it out, so it changed instantly.