what is the difference?

[baddis]

like the title says what is the difference between an unleaded engine and a flex fuel engine besides injectors?

 

[RonD]

Flex fuel vehicle will have a sensor by the fuel filter that can detect what % of methanol is coming up to the injectors, $650-$750 for that sensor.

The computer is different in that it can take the data from that sensor and calculate injector dwell as % of methanol increase or decreases on the fly.

The rubber seals in the fuel system are methanol resistant but I think that applies to all vehicles now.

Someone said cylinder dome shape was different but not sure that is needed or was just a general design change.

 

[baddis]

I am having an issue finding a flex fuel engine and 3.0 in general so I have located a local one from a Sable. I know I would have to change head gaskets and intake. I was wondering on engine only parts

 

[adsm08]

To the best of my knowledge either long block will work just fine in either application. There may have been minor differences in some hard parts, but I don't know what they were.

 

[baddis]

thanks This is the first 3.0 truck I have had that wasn't a parts vehicle

 

[stmitch]

Injectors are the only engine related part that make a difference. Everything else is done through the fuel system and PCM tuning. The early FFV engines had unique heads with slightly different combustion chambers, but they used regular gas heads on the later FFVs. You can run either cylinder head, and still retain your flex fuel capabilities.