Fuel controller mishap

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t3t4si

Member
OK i just posted the thread about finding all the wires, on the ecu, on my 00 si for the apexi-safc. Well it seems we have hooked it up and all the wires are in place after a color match game with the wiring harness. I am running a t3t4 turbo with 440cc rc injectors (high impedence). We have the car running right at idle with the fuel turned down a good bit with no problems or check engine lights. But after around 20 seconds or so the engine check light pops on and the car run irradic at idle ....its like the ecu is blocking the apex controller after around 20 to 30 seconds of the car being on. We just built this b16 and have not broken it in yet and we cant until the fuel controller is fixed and able to tune the fuel curve.


We despritly need help.......help please...... IF anyone has any idea of what this could be please let me know. We are using the factory 99-00 si ecu (pt2)
 
we can't help unless we know which code the ECU is throwing. I'd be willing to bet that your code is a result of your wiring. Pull the code from the ECU and then we might be able to help you better.
 
ecu seems to be throwing (po108) map sensor pressure too high. Do you know of anything that i could do to overthrow this code. Cause the car works fine until the check engine light comes on. When I disconnect the battery and let it sit. Then reconnect it and hook it back it up. It idle's smooth until the car starts to warm up to normal driving tempreture. And when the car starting warming up it throws on the engine light and starts to flood the engine...like the way the car acted before we hooked up the apex controller.
 
first off, unplug the ECU and count to 10 to clear codes in it.

next, figure out how much boost are you pushing. you can safely play with about 10psi with the VAFC by doing a -40% fuel trim across the board, more or less. See the Engine Management FAQ on Homemadeturbo.com for a nice practical howto for the VAFC hack.

Finally, start the car back up again. You should be able to idle without excessive richness or a CEL. If you get a CEL you have other issues such as WIRING, bad/damaged MAP sensor or improper vac line hookup.
 
like i said we reset the ecu and it idels fine but about 20 seconds after its been idling it just starts going rich again out of the blue....
 
the map sensor is freaking out cause it sees positive presure (turbo), i think u need one of those missing link things
 
we havent even driven the car yet.....we have only cranked it and let it warm up. How does the map sensor detect boost at idle?
 
there is no boost at idle.

sounds like your map isn't wired right, or you have some vacuum leak, or you wired the vafc wrong on a wire
 
OK thanks for all the help, ill keep playin with it and re-wire it. I also have a missing link from when i was running an fmu ill put that back on just to see it could bypass the map sensor pressure too high. Today is a new day and maybe a lucky one. Thanks guys
 
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