I'm new here and this my first post, so hi everyone! I have a 99 Civic SI that is surging badly. I will list what I have done and what I have checked for this problem. I have a DC 4-2-1 header, AEM air intake, AEM fuel rail, B&M fpr and gauge, Flowmaster exhaust, CTR cams, Edelbrock 65mm throttle body and an AEBS intake manifold. I just recently installed the TB and IM, that is when the problem occured. It is surging from 1000-2000 rpm for 3 to 4 cycles, then from 1000-1500rpm for another 3 to4 cycles, then settles at 1100 rpm. I have checked for all vacum leaks, the vacum lines, TB, IM, map sensor, TPS and IACV, there were none. We drained all the coolant and disconnected all the coolant lines when installed as well. We adjusted the idle screw and that didn't help. We chacked the volts on the TPS, fixed it and that didn't help. The ECU has been reset numerous times, usually after everytime we changed or adjusted something. The only code popping is code #45 (to rich or to lean), we fixed that by bumping up the fuel pressure. Code #14 did pop up but that happened while we were messing with the idle screw on the TB. We reset the computer and it has not come up again...yet. The IACV is fairly new, last summer (2003) so I am hoping that I did not blow that again, yes I blew it once before with a 70mm custom made TB from a ITR. There is nothing done to the ECU and no VAFC of any sort. I was told to check the idle screw under the throttle plate on the TB to see if that works, but its to damn cold here in KC, and my garage is full of crap. I am kinda stuck other wise, so please help as much as you can.

 

Are you sure that you have enough coolant in the car and have bled all the air out?
This can cause this. If this doesn't help, let me know.

Otherwise, we would be glad to take a look at it for you.

Tim Herron
Forward Thrust Engineering
Kansas City, MO
kids806@msn.com

 

Yeah I'm pretty sure that I have enough coolant in the car, I'm pretty **** about the car, and as far as I know of we bled the air out of the system. I might have to take you up on that offer. Is Forward Thrust Engineering the name of your shop? I sell at an aftermarket WD (Keystone, I go by slim) and haven't heard about that shop. Where about are you in MO, you can PM me or email me at slimsi99@kc.rr.com if you want to talk some more about this.

 

EE Chris: Sorry I don't have permission to IM for some reason. I have no idea what the idle is wit the IACV disconnected, but I will check on that. It will probably be tommorow though, it is still kinda cold here. Do you mean adjust the main idle screw to fix it?