IAC counts high

[dhworkin]

New to this forum, learned TP5 on gearhead. 95 truck 350 L31r vortec heads TBI 7427 OD. Problem now is that it’s sucking bc the IAC has 40+ counts at idle and 130 in gear. Does it when it’s cold and when the a/c compressor is on. I had it adjusted to 10 counts at idle and 70 in gear. What do you think went wrong? Thanks

 

[docstoy]

So scan data shows your tps now and what was it before ? First thing that comes to mind is , (qoute) I had it adjusted to 10 counts at idle and 70 in gear. So if tps voltage is also different now then I would first ck your minimum idle rate to see if throttle plates are not opened as much as before and minimum idle rate screw has backed off , if it has , would probably remove screw and use a little loctite to possibly prevent from happening again unless your not happy with your tune and doing changes often to modify or change how it's performing.

 

[PlayingWithTBI]

Check for vacuum leaks.

 

[docstoy]

Introducing or having a vacuum leak will just drive your IAC closed or lower counts then if closing all the way it will just beat itself to death trying to go further .

 

[PlayingWithTBI]

Introducing or having a vacuum leak will just drive your IAC closed or lower counts then if closing all the way it will just beat itself to death trying to go further .

I knew that - WTF was I thinking? Thanks for correcting me.

 

[dhworkin]

It was the MAP sensor. The IAC counts are right on target and now the pcv has a loud rattle. Is that normal? Docstoy, never been happy with my tuning. Long story short, I tuned it for 3 years with the wrong knock sensor, box read for 350 but it was a 305 sensor. Things have been a lot better now but I’m going to need All the help I can get. Thanks,

 

[docstoy]

If you have full vacuum to pcv and vent tube on other valve cover is not clogged and vacuum is steady, I would say replace, rattle could be sign of low vacuum , or seat in valve warped

 

[dhworkin]

I have the EGR deleted so I have two vac ports plugged on the front of the throttle body, one on the driver side of the PCV port and one on the passenger side. What side should I use for manifold vac reference?

 

[docstoy]

Which side is map on ?

 

[Scooterwrench]

Have you checked to see if the PCV vacuum port in the TB is clogged or maybe the PCV line. That would cause high IAC counts trying to compensate for PCV flow that it's not getting and the PCV rattle.