i use to have 30's on my car no problem now i have 42's when cold starts up fine but when its warm its a hard start or fluids. any ideas what i do is try to start it warm and when it doesnt fire i pull the fuel pump relay let it fire then plug it back in and its good and starts.

 

What year, make, and model is your car? What mods have you done? Why did you switch from 30 to 42? Did you upgrade your fuel pump? Is it forced induction or N/A? Is the MAF calibrated for the 42's, or the 30's? Is it a stock MAF sensor or aftermarket? Is the computer tuned for your set-up? Most people here could answer your question in seconds, you just have to add more details...answer my questions and somebody will know right off the bat what the problem is.

 

And what brand injectors?

 

Calibrated maf's will do this to you every time.

You did it wrong. That is all. Get a Quarterhorse and stop ****ing around with mickey mouse bull****.

 

went to a turbo set up pro-m maf calibrated for 42 injectors bosch injectors. if i dont have quarter horse yet. cant get it untill 1-1-11 what should i tell the tuner to redo?

 

calibrated maf is whats ****ing you. get the quarterhorse

 

hold your foot to the floor on the accelerator when cranking to put it in clear flood mode and see if it'll start........if so it could be what addermk2 ststes........try posting on the turboforums.com, but I'd leave on3 out of it as they are on3 haters there and the thread will turn into an on3 bash and or be deleted.

 

He doesnt need to see if it what I am stating. It is a common problem when stepping up to a 36 or 42# injector with no tune. The cars ECM does not poll the MAF during initial cranking. So the car is injecting the amount of fuel a 42# injector will squirt per the pre-set injector duty cycle, and the computer only thinks it has 19# injectors. So the car goes instant rich, floods out and wont start. This also causes low RPM surging and studdering. Sometimes even a stall.

Get the car tuned.

 

All I was recommending such for was to make it easier to start then getting out and pulling relays, I have a friends s/c car with 42's that does the same thing with no tune, all he does is hold the foot to the floor, simple solution until a tune is had

 

Works every time on Brians car.. 42s with not tune just the mass cal. for 42s.