1987 Integra Turbo (D16A1)

I installed the Apex-i S-afc today and drove around with my original fuel system (240cc stock injectors, Vortech FMU)and the S-afc with no problems. Then I took out the old injectors and tossed in some 450cc 'blue top' DSM injectors and removed the Vortech FMU. Now the beast won't even start!?!

I've tried several settings. Here is where I am now:

Pressure sensor 06/06
4 cyl (rpm's read fine)
Increasing throttle (reads fine)
1000rpm at -45%
crossover at 50%

She'll turn over but not even rough idle. There isn't even a single sound of combustion. Why won't the car even start?

 

Check your AFC wiring, make sure that you didn't cut the injector wires. Also, -45% is WAAAAAAAY too lean. Granted, it should turn over, but lean it to -38% and start there. :P

 

Thanks for the help. I doubt that I cut an injector wire but starting at ~38% can't hurt.

Any other ideas?

 

well all u really changes was the injectors. they are probably bad. i had a 90 civic si that i ran an s-afc with stock in jectors and did like u did then threw inbthe 450's changes it too -45 % and she ran fine. id check the injectors make sure they are working properly

 

Did you not multimeter your O2 voltage? That will run you ~.12 volts at 20inHg@800rpms on stock maps and, on most SOHC motors, you will run lean, but, if you ran fine, that's cool. The mathmatical percent of increase 450cc have over 240s is 46%, so...

 

Alright. I think I found the problem. My guess is that my resistance in the injectors is incorrect. Getting out the multimeter to see what is happening in there...

:P

 

Yup. That's the problem. Foolish I to assume that all p&h were set to a standard resistance.

Stock injectors 2ohm
DSM 450cc BT 12ohm

Anyone know which resistors I need?

 

10w 10ohm inline resistors form RadioShack will work, or a standard OBD0 "resistor pack" available on any multipoint fuel injected OBD0 car.

 

Er... wait. Looking at it I realized that I don't need any more resistance as that is the problem.

I have 12 ohms resistance compared to my original 2 ohms resisitance at the injectors. The stock resistor box throws about 6-7 ohms. Therefore, if I remove the resistor box I should be down to 5 ohms of resistance... a lot closer to the 2.5 I'm aiming at. Perhaps that will work.

 

Hrm, I'll be interested in seeing how this problem works itself out.