we just finished isntalling my ported vf34, helix 660cc injectors, walboro 255lph fuel pump, helix up-pipe, and uploaded the UTEC v5.0 firmware and also uploaded the stage 4 map. now after doing the install of the parts, and uploading the proper maps, we attempted to start it up. upon start up it backfires like hell!! now could this be from the excess fuel being dumped into the engine when we were priming the oil and fuel systems before actually firing up the car? it's also throwing an CEL, unfortunately we dont have a obd2 scanner handy now. Please help!!!!

 

Hmm... verify that the connectors for the wires leading into your injectors are secure... that little clip has a tendency to pop off and leave those wires loose. Also, I assume that you told the UTEC the injector size? 600cc? Verify fuel pressure, your injector size is a function of fuel pressure - for instance, I thin the perrin 816 modified STI injectors are 816 cc at 43 psi (I could be wrong on the actual numbers but you get my point). Forgeting injector size will completly screw up everything.

 

we were at a loss, then found that we had a vaccum leak. we went back through all the vaccum lines and disconnected then connected all of the electrical clips. started her up and "viola" , working suby! now my only problem is that the fuel rails were bent a bit, so the rails weren't sitting on the injector properly. we gently bent the lines back to almost original condition and so far no problems.

 

Nice... are you using stock rails? Take a look at the Perrin rails, very nice if you are looking to upgrade.