I just completed my LS/VTEC conversion and faced with the following problem:
When engine goes idle initially stops on 1.500 RPM, and them after 1-2 sec. drops to 800-900 RPM and stay stable on this level.

Problem is that this effect very effectively disturbs VTEC, because computer lights up error codes and forces engine to use "safety mode" and car stalls.

Do you have any ide what I should do to get rid of this problem.
My setup is:

'94 LS teg OBD-1
B18B1 OBD-1 block
B16A1 OBD-0 head
P30 - OBD-1 ECU
Harness modification

 

Problem could be that you have no knock sensor in your B18 block. vtec ecus except for the 92-95 are programed for a knock sensor reading. when it comes back without this reading it throws error codes. You can do 2 thing to fix this if this is th problem. you can hook up a knock sensor as http://www.c-speedracing.com shows in their ls vtec how to. or you could replace your ecu with the 92-95(this takes many wiring changes, wont plug right in) GOod luck

 

As a matter of fact I have P30 ECU from 92-95 Civic, so it should not be the problem. Any other ideas, I lost hope. The second problem connected with it is that A/F ratio seems to be extremaly lean.

 

the p30 ecu that u are usin read the knock sensor u should have got a p28 ecu chip to run dohc vtec and that will disable the knock sensor if u still want to use the p30 ecu u will have to tap the block and put a knock sensor