ls 3 e-rod motor help

**gmtech** · 09-25-2010, 05:26 PM

hi i am finishing up a ls 3 e rod motor install in a 55 2 dr sedan.it keeps putting up 171 and 174 lean codes. i can hear a vacuum leak on the front of the engine on the pass side.i figure this is the cause of my code. my question is. i have checked the vacuum to the evap sol and the vacuum to the foul oil plate under the intake they are not leaking and the air filter tubing is not leaking. i think the intake is leaking at the head. has anyone seen this happen on a new gm crate motor? any other normal causes for a vacuum leak in that area i should look for? thanks for any help you guys could offer.doug

**Cutlass** · 09-26-2010, 04:14 AM

It could also be one of the o-rings for one of the fuel injectors. You could try spraying carb cleaner or throttle body cleaner in those areas and listen for changes in engine speed to help locate the leak.
What intake are you using?

**gmtech** · 09-26-2010, 05:38 AM

that was my guess to i got some carb cleaner last nite and that is what i am going to do toady.the intake is stock ls3

**gmtech** · 09-26-2010, 11:53 AM

i found out the problem. it was a stupid mistake on my part.it was the air intake setup we put on it.modified it somemore maf graph now looks great. car runs great.thanks cutlass