Background: I put a brand new built motor in my car this year. I had it tuned on 94 octane on a very safe and extremely rich tune (pours black smoke out the back when i’m heavy in boost). Fuel system wise it has a BR double pumper, Aeromotive FPR, FIC 1250 injectors, stock fuel rail. The car is running 25PSI out of a 6262 .82 turbo, stock ECU speed dencity. .

Whelp I put my car away for the winter, in doing so I pulled all the spark plugs and fogged the cylinders with oil. So naturally I check the condition of the plugs to see what they were like. I was assuming they would all be black with carbon as the car is running uber rich. The spark plugs in cylinders 2-4 were as expected, very black. Cylinder one however was white indicating a lean condition. As of right now i’m not sure why.

Could this be due to me using a stock fuel rail?? Is its something to do with my stock intake manifold?? The car is away for the winter, so I can’t test anything out...but I wanted some advise on things to try.

Any thoughts??

 

I think it has to do with the stock intake manifold design, i have seen this happen quite a bit with the stock intake manifold,including my own car,i have a FIC fuel rail so that's not the culprit,i always run my engine on the rich side to compensate for it.

 

Send your injectors to RC engineering and verify that number one is flowing as well as 2-4. If its not that could be causing your lean problem.

 

Its just off since the injectors are brand new....I'll be looking at the fuel system and intake manifold. Hopefully one of the two is the culpret. I just thought there might be something i'm overlooking.

 

No one else has ran across this?? I find it odd since the car before the build ran great, all the spark plugs where a nice brown colour.

 

Swap injectors into a different cylinder and see if the "lean" look follows it. If it does then its injector, if it doesnt then its airflow in the manifold. Cylinder one is at the back of the intake manifold (furthest from the throttle body) so typically it gets a little less airflow which would go rich. It is also the last on the fuel rail but I have never seen that make a difference.

 

Thanks, thats a good idea. I'll do that.

 

excellent advice as usual from johnbradley. we have had multiple issues from FIC injectors lately. Im on my second set and they were brand new as well.