Hey guys, got a few questions here. I am working on a 306 GT42R, AFR, Solid roller setup with FAST bank to bank. Previously we had MSD 50lb injectors installed and a basic tune with them. We switched to the RC Engineering SL4-750 injectors and I changed the fuel calculation parameter to 75lb injectors. The car would crank, but is EXTREMELY lean with the 75lb setting as in you could not give it gas without a stumble and nearly dying. I had to move the injector size back down to the 50lb setting to get the 75's to run decent.

Any ideas on this? Just wondering if that is the normal behavior on these injectors or if there might be something else causing this.

Also, cant get the wideband 02 to show up. Sensor is fairly new, but sat up for a year or better. Is it possible to have to reconfigure the sensor again?

 

Injector opening time might be a lot different between the two - ask RC what they recommend, but that's where I'd start. 1/2 a millisecond for opening time makes a BIG difference.

 

P.S. You will probably have to rework parts of your map anyway - it's never as easy as changing a number.

 

Do you have the *opt file or is that a serialized o2 from fast?

 

It is the serialized o2 sensor. Do you know of anywhere I can download a copy of the *opt file? Will this file allow the use of any NTK L2H2 sensor even if its not purchased from FAST???

Thanks

 

Also called RC and they said these injectors have a delay of 1.4ms. Currently I am set to 1.2ms for the MSD 50's so I am gonna give that a try.

 

yes it will & you have to get it directly from fast as the opt files are ecu specific. its like 25 bucks and they will send it to you via email in a few days, gl

 

Got the sensor to work. Actually the connector got warped a little and needed a little persuasion to seat fully.