Juancm5483

I used to have a Power FC, but I have downgraded to a Pettit Unlimited ECU. Everything was ok with the power fc and I was at 10psi with base maps. I installed the pettit unlimited ecu and everything seemed fine until I got on it. It is now at 14.7 psi the problem I am having is after the transition and 14.7 psi the car starts misfiring a lot and releasing huge amounts of black smoke. While this is happeneing the car feels like its fuel cutting but also sounds like prrraaaaaa! this happens ar around 5,500 and up. My mods are intake, catback, stock main cat, pettit ecu. I have searched this but found no results. Does anyone know what is causing this?

93BlackFD

injector duty change over (secondaries kicking in)

perhaps you need them cleaned

93BlackFD

injector duty change over (secondaries kicking in)

perhaps you need them cleaned

Juancm5483

If its the injectors, Im thinking that it wasnt hapenning before because it was less boost more like 9-10psi as opposed to 14.7-15 psi that I have now. Would this change in psi be the cause of this injector problem?

911GT2

It very well could be. The injector duty cycle is very very high at 14.7 psi, probably close to 100%. And if they aren't functioning perfectly to begin with, then operation at their limits would only exaggerate the problem.

HeatTreated

Get a Elec. Boost Controller! (especially on stock IC)
with the weather getting cooler it could spike high after transition, I have the same ECU and saw up to 16psi with main cat, before I got the Profec B.

It was really hard to control boost with the manual bleed type b.c.

Im sure the ball & spring would have worked better.

Juancm5483

Im thinking about getting different restrictor pills. I want to stay at 12-13 psi. Does anyone know what size exactly?