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Affordable Flex Fuel Sensor

73K views 135 replies 37 participants last post by  sonicboom141 
#1 ·
I was going to purchase the Haltech Flex Fuel Sensor to use with my Haltech PS1000, but through some searching found that they are just rebranding an OEM sensor and marking the price up. I found that Dynosty is also selling this OEM sensor without the Haltech sticker for $199 (compared to $232 from Haltech).

Through a little more searching, I found the sensor is actually made by Continental and is used in some of the newer GM and Holden vehicles.. and can be ordered from any GM dealership for MUCH less than Haltech.







The only obstacle after obtaining the sensor through a GM dealer is getting the connector for it. Haltech charges $38 for the connector and terminals, Dynosty will sell you the same thing, but marked up to $50. I contacted Continental and was able to get their source for the connector. However, the connector is not available in small quantities. I did find another connector that works if you remove two tabs from the sensor side (I found that Haltech does this also).

Here are before and after pictures of removing the tabs:







The new connector (that costs less than $2) fits great.

 
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#106 · (Edited)
Whats good E,

Mounting things with moving parts directly to an engine is typically a cost cutting move, and should be avoided at all costs whenever possible.

That double Y'd fuel feed setup you posted looks baller, but is pretty pointless. The ethanol % changes extremely slowly (if at all), so the extra lag from the fuel return is ok. The sensor is mostly there for tank fill ups where the new gas probably has a different amount of ethanol in it.

Every OEM install of that flex fuel sensor I have seen, places it in a cool, vibration free zone - typically on / near the strut tower which has thick metal to dampen vibrations.

Do use hard lines whenever possible, soft line (even ss braided) sucks and is a hack for doing the job right.

Yes the OEM clip on connectors on the flex fuel sensor are cheesy, but they are extremely reliable. You dont even need to think twice about using them. OEM's do not mess around when it comes to fuel system safety, they would get sued into oblivion.
 
#107 ·
The FPR will be mounted to the rail as I planned. I've seen many people do that with out issues on engines that vibrate much more than mine and make much more power than I plan on. I will mount the flex fuel sensor on the chassis somewhere around where the stock fuel filter is located.

On another note. If the flex fuel sensor was mounted securely to the head with the 4 bolt holes and the hard line was secure as well. I don't see it being a point of failure.. It's not like the line will hang from it and it will be on a flimsy plate constantly vibrating. Anyway.. If you guys feel that it will be an issue if securely mounted i have decided to mount it to the new location.
 
#109 ·
Does the flex fuel sensor need to read temp to interpret ethanol content? or is temp just an option for logging?
 
#111 ·
Flex fuel sensor measure the dielectric constant of ethanol-gasoline fuels which change in proportion to the ethanol content. The temperature of the fuel changes the density of the fuel slightly (pure ethanol has a density of around 0.7918 g/cc at 20C but less as the temperature increases). This is one of the factors that will affect any fueling (MAF, SD or aplha-n) calculation and systems that account for it can be a little bit more accurate than those that don't.
 
#114 ·
I mounted my sensor over the motor mount. Looks good IMO. Plus it's not seen once the intercooler piping is installed.

 
#121 ·
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