Flex Fuel on Fbody

[LSxpwrdZ]

Has anyone effectively swapped in a different PCM/OS and wired in a Fuel Composition Sensor and made Flex Fuel work?

We just got a station close by that is now offering E85 and I want to add the fuel composition sensor so I can drive in every now and then and top my tank off with E85 however I don't want to flash the car for the new stoich ratio everytime I decide to put some E85 in the tank. So I've thought about using a 04 GTO PCM or even a 02 Truck PCM/OS to get it working.

Anybody looked into this?

Are the 04 GTO PCM's even capable of enabling this feature with a FCS added?

[LSxpwrdZ]

Well since I'm getting no answers I'm going to take the plunge and order a GTO PCM along with a green plug cap to replace the red cap. I will then order a fuel composition sensor and wire it into the PCM. I have pinouts showing where they go on the unused pins.

Then I'll have to figure out how to enable the PCM to actually look for the composition sensor and adjust stoich ratio. I'm thinking I may have to find a 2004 flex fuel truck with the same OS and just do a fuel segment swap. Maybe someone can steer me in the right direction on that.

[carlrx7]

any luck with this?

[murphinator]

not what your asking for but maybe an alternate thought... what about one of Frosts dual flash setups with one set to gas and one to e85 since your talikng about buying another pcm and a composition sensor anyways - spending $$ either way

[Wnts2Go10O]

wouldnt you need different injectors?

[LSxpwrdZ]

I'm changing motor setups now anyway's so this idea is now pushed off til later, but I intentionally used Siemens 60# injectors on my NA 403 just for this reason. I had plenty of room to grow on the fuel system with this setup.

I didn't really look into it any further but I'm sure it's easily done with a segement swap from a flex fuel vehicle of the same year and OS as an 04 GTO. I couldn't find a flex fuel OS that matched the only GTO OS I could find which is 12587604. I found a 04 Tahoe that had an OS of 12587603 but don't know if that'd work or not.

[robbyredneck]

why not just use the flex fuel truck pcm?

[LSxpwrdZ]

Because all 03-up Truck's had drive by wire and I don't want to put a drive by wire throttle body and pedal assembly in my car. The '04 GTO PCM has the IAC drivers and was cable driven throttle body. The Truck PCM's may have this hardware also but I can't go full in with all this to have a hickup like that to scrap the whole idea.

[robbyredneck]

righto, forgot about that.

[zippy performance]

You could use an 02' truck setup. My Tahoe is an 02' with a standard cable drive throttle body and has the flex fuel sensor. If you use this though you'd want someone with Tunercat or EFI Live to modify the E85 spark adder tables for you though since HPT hasn't added them as an option for us to modify.

[Higgs Boson]

I'm pretty sure the Beta has E85 adder tables but maybe not for 2002?

[LSxpwrdZ]

If you don't care post up your stock calibration from your truck so I can check it out. This way I could possibly find an OS from a Fbody to just do the fuel segement swap.