High idle when hot 96 FZJ80 (1 Viewer)

[Mojo353]

Hi Guys n Gals, anyone know what these two hoses do ? I think part of the vsv system
(96 FZJ80) been dealing with high and erratic idle when engine is hot, I'm thinking unmetered air is causing it. Have replaced throttle cable, cleaned throttle body, IAC and TPS.
Any thoughts ?
Both hoses go to a connector or sensor? On the block under the intake manifold to the right of the oil filter and behind the fuel filter.

 

[Diesel-Runner]

Download the factory service manual here FSM - 1996 FZJ80 FSM - https://forum.ih8mud.com/resources/1996-fzj80-fsm.27/
Checkout the emissions control system the starts on page 771
Those go to the evap vcv and tvv

 

[Mojo353]

Appreciate the reply thank you, I have the FSM and kinda understand what these systems do, I guess I'm wondering if I'm on the right track in that they could be the culprit? FSM shows how to test them etc and I can follow that but it doesn't really say these could be the problem.

 

[Diesel-Runner]

Any air leak between the intake valve and throttle body will cause idle issues. So could they be the culprit? Yes. Are they? Plug them off while you are experiencing the high idle issue to know for sure.

 

[Mojo353]

Great , thank you. Will do.

 

[Mojo353]

Replaced the accelerator cable and bypassed the EGR and problem solved.

 

[LandLocked93]

Was going to mention the accel cable. Perhaps your other fix applied as well.
Just a data point for an old cable:
Had a low idle when cold and normal idle when warm.
Adjusting the cable for normal idle @ cold gave me high idle when warm.
Adjusting the cable for normal idle @ warm gave me low idle when cold.
Turned out to be the vintage cable not allowing the throttle to return to the idle point.
New cable resolved.
Also replaced the throttle pedal assy as it was a glute destroyer either way. lol

 

[Mojo353]

Lol, I hear ya..... I was able to lift the accelerator pedal with my food and straight away the rpms dropped to normal..... simple fix in the end.