‘89 FJ62 Idle issue after transfer case rebuild (4 Viewers)

[atlshaun]

had my transfer case rebuilt a few weeks back and ever since the idle has been very high.

it would initially idle in the 1500 range in park and drop slightly when in gear. If I shifted to neutral it would act as if the gas peddle was depressed and shot to 1500-2000

i changed the FPR and it dropped to about 1100 in P and maybe 900 in D. if I shift it to neutral when stopped it still jumps to about 1300

is there anything specific to the transfer case rebuild that could cause this? seems too coincidental seeing as it never did this prior to the rebuild.

 

[Gimme a 60]

Vacuum shift?

The only thing I can see causing that is a bad vacuum solenoid for the T-case - that's only if you have vacuum shift. If you don't have vacuum shift, I doubt the transfer case being rebuilt is associated.

 

[atlshaun]

i should also add I can grab the throttle body and move it towards the drivers side and idle down the rpm’s

 

[atlshaun]

Vacuum shift?

The only thing I can see causing that is a bad vacuum solenoid for the T-case - that's only if you have vacuum shift. If you don't have vacuum shift, I doubt the transfer case being rebuilt is associated.

i will google this

 

[Gimme a 60]

i should also add I can grab the throttle body and move it towards the drivers side and idle down the rpm’s

sticky throttle cable?


do you have a PTO idle knob that is on??

 

[atlshaun]

sticky throttle cable?


do you have a PTO idle knob that is on??

where is it located I will look?

 

[cruisermatt]

Probably throttle cable sticking or air intake hose cracked, guessing the transmission crossmember was removed and drivetrain lowered to make working on transfer easier, which would have tweaked both the main intake hoses and throttle cable

 

[atlshaun]

Probably throttle cable sticking or air intake hose cracked, guessing the transmission crossmember was removed and drivetrain lowered to make working on transfer easier, which would have tweaked both the main intake hoses and throttle cable

thank you I will investigate both and report back

 

[atlshaun]

The throttle cable seems appropriately adjusted and has some slack in it although, again, I can pull back the actual throttle by hand and lower the idle

I removed all the main intake hoses and reinstalled to ensure they were tightly secured and the idle will still start over 1k when I initially start the truck but then taper down to about 700/750...until I drive it. Once I drive it for a while it stays around 900 when stopped and in gear but if I shift to neutral it will increase to 1500 ish

It also does a somewhat strange thing...if I let off the gas the rpm does not really drop other than as it drops in unison with the speedometer of the vehicle. If that makes any sense.

 

[atlshaun]

i finally figured out how to get this in diagnostic mode and it looks like it is throwing codes 24 and 32

 

[atlshaun]

here is a picture of my plug for the afm should all of these slots have a connector clearly one is missing in mine

 

[atlshaun]

 

[cruisermatt]

No, that one is unused. Not your problem.

 

[toy_tek]

here is a picture of my plug for the afm should all of these slots have a connector clearly one is missing in mine

Not missing. That’s correct.

 

[atlshaun]

Latest and (not) greatest:

I checked the AFM and it passed the testes and seems to be functioning properly.
I pulled the EFI fuse and also disconnected the computer for a few minutes and reconnected

Upon cold starting, the idle drops appropriately to the 650 ish range
I can drive it for 20 minutes or so and it will maintain operating at normal RPM's

However, after about 20 minutes it starts to idle a bit higher and if I s*** into Neutral or Park the RPM will rev up into the 1500 rpm range

There is slack in the throttle cable when this happens BUT I can manually pull the throttle body towards the drivers side and it will idle down to 650 when I do so

It also will struggle to restart and I have to try a few times to get it to start again once its at operating temps

sigh

 

[cruisermatt]

did you really look over the main intake hoses to make sure they weren't split? Almost every original one I have seen is due for replacement at this point.

 

[atlshaun]

did you really look over the main intake hoses to make sure they weren't split? Almost every original one I have seen is due for replacement at this point.

is the series of hoses what you are referring to?

 

[cruisermatt]

Yes

 

[atlshaun]

Yes

I'll remove them this weekend and try to inspect them all

 

[atlshaun]

I had several tears and general degradation in the circled intake component so I ordered replacements from city racer and replaced both of the rubber intake pieces

replaced both and all clamps

i pulled the efi fuse afterwards and all symptoms remain the same after

-starts fine and will idle down to 650-750
-after driving for 10 or 20 minutes it will idle down to 850 or so when stopped

-BUT-

-as soon as it is shifted into N or P the RPM’s rev up to 1500-1700