Car ran great before I swapped injectors. Swapped to 30 lb injectors and stuck in my new tune and the car would BARELY even idle.

Pulled those injectors and they were all firing (all the tips were wet). I decide to stick the stock injectors back in, changed programs, etc (back to the way I had it when it ran great) and it barely runs again.

What the hell could I have messed up?

 

check your fuel pressure regulator, pull the vacuum line of it and touch the nipple with your finger to see if its wet, if it is, raplce it (so long as this is a stock regulator) might cause some problem but just tryin to help. Btw, its not leaking anywere is it?

 

I'll check the regulator, but no it's not leaking a drop. The rail was pressurized when I disconnected the fuel lines to swap back to the stockers.

 

The nipple was dry as a bone.

 

Sounds like a Vaccum leak, start it up and rev it does it clean up at higher Idle? If so then thats your prob

 

the 30# ijectors are probably supose to flow at a lower fuel pressure. you have to know at what fuel pressure they rated. becuase if you put a new injector in and its supose to operate a 39 lbs of pressure and your running 43.5 (stock) you need to account for the difference in pressure through programing.

say they are flowed at 39 and you have stock pressure43.5. well then it 43.5/39*30#injector so its 1.115x30 is your new injector costant ...33.45# injectors because your using a higher fuel pressure.

 

PCMforless made a program for the 30# injectors. I also put the other program back in for the 24# injectors when I put them back in. It almost sounds like it's missing on a cylinder or something. It runs like absolute ****.

JuicinGTA, I don't know where the hell the vacuum leak would be from. The injectors are seated fully and all the vacuum lines check out alright.

 

when you put the injectors in did you use any sort of oil or lube (preferably white lithium grease)to seat the o-ring into the manifold?

 

Figured it out. I had backed off the throttle screw less than a 1/4 turn and the motor didn't like it for some reason, even though it ran with the screw backed out 2 turns when i first started the motor up after the rebuild. Pulled it back out some and it's back to normal, with the tiny vacuum leak still there. ARG.