TinyFC87

before we had the DIY FCD, to prevent fuel cut i had just unplugged the vac line from the boost sensor and it didnt hit fuel cut. now the question is, is that the same thing that the FCD does. becuase i installed the homeade one and it doesnt do much. some advice would help.

Patrick

bigturbo

No it isnt. the fcd plugs between the ecu and boost sensor to alter the signal going to the ecu so it doesnt think your running more than stock psi. By unpluging the vacuum line that goes to the boost sensor the ecu gets no reading at all. I would think it has adverse affects on fuel delivery and timing with the way you have it set up. Otherwise everyone would just do that instead of making a diy or buying the Racing beats one.

bigturbo

doublepost

TinyFC87

true thats what i was thinking.

therotaryrocket

i think you lose the boost timing retard, which is dangerous for the engine, but regardless of boost the extra fuel will enter as the ecu detects the added maf signal. anything else?

bigturbo

Exactly thats what im saying. the Ecu has two maps from what I understand. One for low boost and one for high boost. So the FCD allows you to take advantage of the high boost fuel map without experiencing fuel cut. Where as no reading will probably keep you in the low boost settings and eventually you will experience a blown engine with enough boost.