[Buick] V6 hunting

[rubaduckee]

Hi guys I have a VP v6, I have just rebuilt, now we started it yesterday, when we start it it it starts fine but hunts at idle.
When you push on the accelerator it revs up but takes a second or two to come back down to base idle, I was thinking it may be the IAC?

Any thoughts???

 

[rubaduckee]

Or tps maybe?

 

[codwalop]

there is a few things that can cause it, but it is most likely the IAC, give it a good clean and swap it out if you're still unsure.

also worth double checking vacuum hoses & check for air leaks.

 

[rubaduckee]

Cool thanks

 

[delcowizzid]

is it a totally stock rebuild or modded

 

[rubaduckee]

Full rebuild, pistons, heavy ported heads, cam for turbo, turbo, injectors stage 2 map, roller rockers etc
Tho tune was done with cam, heads and turbo etc before rebuild, so only diff now is new pistons, rings etc

Rebuild was cause of rings

 

[DJ_Cosmic_Fire]

hunts at idle, push on the accelerator it revs up but takes a second or two to come back down to base idle?

Go & get a new genuine Delhpi or Delco IAC & see if that makes a difference considering all your mods.

IMO the custom tune needs to be completely re-done considering all the extra work since the last tune - mandatory - as it is inaccurate in terms of the custom engine build date etc.