Hello Good People,
I would like to adjust the engine idle down from the current 900rpm.
Looking at the RAVE it says the 4.0 GEM should be at 700 ± 20 rev/min
By the image am I in the right area for making this adjustment?

T.I.A.

 

The allen head adjustment is for the base idle, don't touch otherwise you've now changed how much or little air your sucking around the throttle plate. Adjust the idle with the throttle cable adjustment.

 

Thanks ihscouts for the quick response.
I'll not touch that allen head bolt than.

The throttle cable adjustment looks like it doesn’t require any hand tools? Do I just unscrew that large plastic looking tightener for the adjustments?

Thanks

 

Did you do work or replace something that contributed to the high idle?
I don't recall if its all GEMS or just the later AEL ones that can have the adaptive values reset via testbook.

 

fishEH,
When I got the truck in 2016 it had a similar idea.
After reading the many threads I learned that my idle was high. It’s a smooth idle but if I can get lower that would be good.
Last month I had the top of the engine completely removed to replace the cylinder heads and gaskets. The idle is the same as before.
Everything is working fine and just recalled the post about a lower idle speed.

Whats your idle speed?

 

Yep, just loosen the plastic lock nut affair to put a little slack in your throttle cable, warm up the motor past cold idle and fine tune that adjustment with motor running. It's simple old school method and is opening/closing the throttle plate. Just be sure your IACV pintle and bore seat are like new clean before you adjust cable otherwise your wasting time.

 

Sweet, thanks ihscouts!

 

I made the adjustments to the throttle cable but the idle remained the same 900rpm. I can easily take up the slack which increases the idle speed. By adding more slack it does not decrease the idle, it actually appears to be too much slack.

Is there additional adjustments besides that big plastic screw?

Thanks

 

Yes but you'll need an Autologic or the antique Testbook 4 to adjust the IACV. They can turn it in/out through software to adjust it (clue there, it can also be turned manually). Most indy foreign shops use the Autologic, call around and ask how much and if they can do this. You also have a manual slush box, usually the idle speed is around 50 rpm higher than with an auto box.

 

Ol rats!
I was thinking I could simply do it on my own without any additional electronic hardware. I should have kept my HawkEye device after all.
Thanks for the tech support, much appreciated.