I have a 92 preldue with swapped in h23, with turbo, 5-7psi. aem rail, 450cc injectors, s-afc. the car runs good till I start to hit boost than than engine light comes on, than the cars run good till aboput 4000 rpm, than I have a lot of black smoke, it sputters really bad. I just put on a new o2 sensor like two days ago. so I check the ecu for codes this is what I got. 37-map sensor 41-o2sensor 7-TB sensor 12-egr 23-knock sensor. anybody have any idea on this? thanks ray

 

are you sure about your boost level? Is your boost spiking causing the cels? Someone else got any input?

 

do you have a check valve on the map sensor? or a missing link?

Because your ECU will freak out if it sees boost... look into it...

 

the afc doesnt require check valves it manipulates the map voltage to read as if the car wasnt making boost.

either your afc is wired wrong, you are hitting too high of boost for the voltage cut to correct, or the afc values you have inputted are wrong.

 

iam only run 5-7 psi. now that you say maybe I have it wired wrong, I just swapped in the h23 a week ago. but before that I had and f22a1 with the same turbo set up. and the afc was wired to the f22 ecu. all I did was plug in the new ecu with the same wiring set up as the f22. is there a difference on were the wires shoud go on the f22 and h23?

 

you will have to look that upyourself, sorry

apexusa.com i think

 

there might be a diff in the way its wired from ecu to ecu . that would be the 1st thing id check
my guess was the missing lnik /check valve, but i didnt see the safc at 1st

 

i think that it would be the check valve or yeah your afc might not be wired right i think there is a difference in the wiring setups fomr ecu to ecu

 

ok here is what i did, I switched the afc setting back to -30 across the board. The car runs a lot better no sputtering at 4000 rpm, no engine light, but the car is running rich. when I start the car the a/f gage is in the orange witch is stoch, than it slowly goes in to red witch is lean. than the a/f gage reads nothing, no lights at all. so I can't depend on that gage. but i see black smoke coming out of the pipe. so i know i'm no lean, is there a nother way I check my a/f? thnaks t

 

dont trust your a/f, put it on a dyno or get a wideband 02.

 

pete, where did you get your car dynoed at? how much are wideband 02s?

 

im prob buying a wideband very shortly.
but the cheapest place i found is Xotic Motorsports, its like 30hr maybe 45 from your place.
other option is pay out the *** and go to Perofrmance Specialties in POttstown ,he knows his ****, but expensive as al hell .