I have a 350 motor that I got out of another iroc to build. It's a stock bottom end motor with a comp cam 264 intake 269 exhaust and valve duration .488 & .495, vortec heads with 1.5 roller rockers and comp cam beehive springs, cloyes timing chain, comp cam push rods, hooker shorty headers, Edelbrock Pro Flo XT intake with 21/lb injectors and fuel reg @45psi, Pertronix flamethrower II distributor with MSD coil.


The motor runs decent for being untuned. Think I need bigger injectors because the motor sputters a little bit at high rpm's and has ok throttle response. Main problem I'm running into is after the car has sat for a day or two when I first go to start it it takes about 15 seconds of cranking before you hear any firing. Then it slowly starts firing more until it finally starts then I have to hold it at 2 grand for awhile until it warms up a bit. I didn't know if the 9th injector has anything to do with this problem. I'm kinda new to some of this stuff, but would really appreciate it if someone could help me out!

 

It needs tuned. It needs more startup crank fuel

 

I've just been waiting for my dynomax dual exhaust to come in. So when I get my exhaust I'll be able to get it tuned. So tuning will solve the starting problem?

 

Well assuming no electrical or other mechanical issues it certainly sounds like a tune issue. Stock ecm chip can only do so much. It would be extremely helpful to do logs and see whats going on. Even more so to see air fuel ratio with wideband and plug reads

Could also be spark timing. Is base set properly and to what value? Does it want more or less? That combo shouldnt need much more if any more than stock timing

It may want higher idle speed to with cam. Need to reprogram target idle speed and reset iac and throttle screw


Simple quick try would be jack fuel pressure up to 55-58 psi and attempt a cold start like you are doing. See if it starts quicker and holds it own idle.