SndOfProgress

Hey guys. Apparently i have low compression when i start my s4. It takes a while to get goin, and usually floods. I have been told their used to be a kit that inhibits the amount of fuel at startup because of this problem, but it is apparently old and hard to find. Would an afc (safc 2 or neo) be the way to go for this? Would I be able to adjust the fuel at such low rpms, like 200-500... not really sure what the startup rpms are. Any help is appreciated, thanks.

RotaMan99

Nope. 800 Rpm is the lowest you can adjust. PLus when you first start you engine, the ECU uses the pressure sensor or some other sensor instead of the AFM for the first few seconds.

My old engine had low compression too and used to always flood. I wired up the fuel pump to only come on while in the ON position , NOT while cranking the motor. So Basically while the motor is turning im cranking the 1st time its basically getting the motor to spin and then I release the key into the on position. Motor still turning slowly, this turns the fuel pump on to build pressure. When the engine stop turning, I crank it again and it starts up only on the pressure in the lines and not the pressure created by the fuel pump. that way the first crank usually would clear any fuel in the chambers that may have leaked and on the second crank, the engine would start right up.

Sounds confusing to do, but its not. Wiring it up is the time consuming part.

SndOfProgress

yeah. thats exactly what mines been doing. a guy w/ the mazda dealership here told me that if you actually push the gas all the way down during start up it will cut off the gas to the engine. sounded a little iffy to me, but, i tried it, and it seemed to help a little... i dunno if what the guy from mazda told me was true, or that im just imagining that it helped. lol..

RotaMan99

He is right, but he also didn't tell you that the fuel cut while flooring the pedal only works on Series5s. I used to press the pedal about half way and it seemed to help start the motor without flooding.

88turbotime

This is what everyone says, but the last time i flooded my car i pushed the gas to the floor and cranked and it started right up, and mine is an 88 TII. Maybe it was a plesant coincidence.

RotaMan99

Your fuel pump will still turn on but if you floor the pedal on a Series 4 you are only allowing more air into the motor which will deffinatly help it start a lot better. Never said the flooring the pedal wouldn't help start the motor on the Series 4, it just wont turn the fuel pump off.