Idlew Air Control Valve 1996 5.8L

[jrshepherd]

cratchhe::banghead:Hello. I know someone knows more than me and can help. I had the engine rebuilt on my 1996 5.8l. I installed forged pistons, cam, roller rockers, trick flow heads, full length headers, 26lb injectors, new air meter, arp head studs and a load of other new parts. I have had a lot of issues with vacum leaks/ lean codes (p0171 & P0174). On the other hand, I have had to replace the IACV twice. after 500 miles +/- it will stick around 2000 rmp and not let the idle drop. When I disconnect the IACV it runs great with readjustment to the idle. Any suggestions? Thanks

[chuzie]

Why is it failing? Is it getting contaminated with carbon?

[jrshepherd]

The timing was off and prevented it from work. Once the timing was adjusted everything works great. Thansk again.