You are having warm start enrichment which is the issue. Either remove it from the tune or figure out why the DME is enriching when it is warm.
If it was fuel pump pressure valve you would not need to pull the relay for it to start right, you are injecting too much fuel on warm starts. 440cc injectors are smaller so it will inject less on the warm start so that is most likely the only reason they work ok.
I would fix the issue which is for some reason your DME thinks it needs enrichment fuel on warm starts...This is all related to your head temp sensor, if the sensor is good then the wiring has issues or the tune has warm start enrichment in it and needs to be removed from the tuning...
Simple issue too much fuel on warm starts. Fix the issue don't Jerry-Rig it with small injectors and a secondary kit that will need a standalone that is boost sensitive to run that motor. |