93 FZJ80 stalls when cold, runs fine warm

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westafari

westafari

Sand Cruiser
10 Year
Joined
Aug 25, 2014
Threads
10
Messages
210
Location
Roanoke, VA
So...now that we are having some cold nights I've discovered that my 80 has a tendency to stall before it warms up. Like, I'll pull up to a stop sign, take my foot off the gas and it will just die. It starts again no problem, idles fine at start up and then once I've driven it a few minutes the stall issue goes away. I've looked at the troubleshooting chart in the FSM and will probably work my way through that systematically but before I go down that rabbit hole I was wondering if there's anything quick I can check, or if anyone has experienced this? I've searched here a bit and didn't see anything that seemed real applicable to this problem. If I keep just a tiny bit of pressure on the gas pedal it doesn't stall out. I have been thinking its something to do with the throttle body/TPS or the tension on the cables but again, if its a warm day or the truck has been driven a few minutes theres no issue. Idle is between 700-800 RPMs when its all warmed up. Thanks!
 
While there's no substitute for a proper troubleshooting procedure as per the FSM-and other sound advice from fellow mud members, I suggest you may adjust the throttle cable just a bit-enough to avoid the stall while cold. If after this it keeps stalling and/or the idle goes way up when warm, you can always go back to the original adjustment and move to the next step of the troubleshooting.
FWIW, a friend had quite the same issue last winter-curious isn't?. He adjusted the throttle cable and the issue went away-as far as I know.
Good luck
Cheers
 
I just replaced the accelerator cable the other day, that definitely made a difference in how the truck drives, old one was crusty as heck and made the pedal really stiff/sticky. I've been meaning to pull my throttle body off and clean it and possibly replace the transmission kick down cable too as it is kinda thrashed looking. I have fooled around with the tension on the accelerator cable a bit but it doesn't seem to affect the cold stalling issue even if I get the RPMs up to 1000 or so during normal "warm" temps.
 
I thought about replacing my sticky/stiff cable but the more I wheel it the more I like how it makes holding throttle off road a breeze.

Sounds like an IAC (Idle Air Control) valve issue. May need to be taken apart and cleaned. You could just try squirting Throttle Body cleaner (or brake cleaner) into the port while idling (open and close the butterfly with your hand to rev the engine slightly while doing this).

Opening and closing the TB while you squirt the cleaner into the IAC port sucks the cleaner into the IAC passage while the vacuum attempts to move the valve open. Repeatedly doing this can get the valve moving properly which will get the cleaner in and around it, at which point it should get the gunk out. This method has worked for me on other cars just fine.

IAC valve does just what it sounds like it does. When the TB is closed it opens slightly and allows the proper amount of air to bypass the butterfly valve. When the valve gets sticky it may not open properly when cold, resulting in the stall. The issue is not with your cable adjustment, more than likely its the IAC.
 
Last edited:
SmokingRocks said:
I thought about replacing my sticky/stiff cable but the more I wheel it the more I like how it makes holding throttle off road a breeze.
Click to expand...

haha, nice! Do you have to lift up on the pedal with your toes to ease off the throttle? :hillbilly: I was pretty psyched after replacing that cable, was getting tired of lurching away from stop signs and red lights. It was super easy to replace.

Thanks for the tip on the IAC, I'll spray that thing down tonight and see what happens.
 
Ha no mine isn't that bad, it returns to 0% throttle, when it does get that bad I'm sure I'll replace the sucker.

Let me know how it turns out.
 
X2 as @SmokingRocks . Now that you know isn't the cable, the IAC decidedly seems the next suspect. The cleaner most probably will do. If it does, when you aren't in a rush and have a few hours, take it apart and clean it thoroughly...you'll be good for another 15 years or so
Let us know
Cheers
 
I'm gonna pull that IAC off ASAP and spray it down with throttle cleaner. For now I've mastered the art of 2-footed driving until the rig warms up :hillbilly:
 
Before you pull it off, just try spraying into the port while modulating the throttle by hand with the engine on. I've never had to fully disassemble an IAC because this method usually works so well.
 
Mine just did something similar. It turned off after idling for a few seconds. Started right up again and was fine after that. It also idled high for a minute or so. Really cold right now here too.
 
DARKNESS said:
Mine just did something similar. It turned off after idling for a few seconds. Started right up again and was fine after that. It also idled high for a minute or so. Really cold right now here too.
Click to expand...

I saw your post but it didn't sound like what I'm seeing. Mine will cut out repeatedly until I've driven about 15 mins then its good to go. I got a txt from a buddy in Evergreen yesterday, -6 at his house. I used to live in Denver/Evergreen/Conifer, definitely miss it.
 
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Take the intake tube completely off and it should be on the right side inside the TB if you are looking at the TB plate. It might be hard to see because you would practically have to be looking at it from the windshield.

Where the IAC connector is is where the actuator lives. I'm not sure if you have to unplug ur MAF sensor or not, some engines wont fire without the MAF reading something IDK someone else might chime in here.
 
This may be easier with an extra set of hand helping you. I would get the engine somewhat warm so that you know it will idle right. Then I would take the intake tube off but keep it close (it houses the MAF) in my experience without having the intake tube on the engine will die.

So, I would have a buddy in the drivers seat, and I would squirt some TB cleaner into the port then just hold the intake tube loosely on the TB. Tell him to start the engine let it idle for a bit then modulate the TB plate by hand. Do that for a bit then stick the spray tube in between the TB and the intake tube (still try and keep the intake tube somewhat on the TB to keep the engine running) close the throttle so it idles and spray the cleaner into the TB. That way it should get into the IAC port itself, repeat tons of times.
 
Just wondering how your cruiser starts up when cold. Very high idle slowly dropping down, does it take around 5 min to get to operating temp or a lot longer? May want to check that to help with TS. Reason I'm asking is because I believe the iac is electrical ( haven't looked at the manual in a few months which is a good thing). It receives a signal from the ecm and you should feel a click on the iac when shutting off a warm engine. I ask about normal startup when cold because the iac steps down in sequence depending on the ECT. So I would agree probly the iac. Also on cold mornings you probly have the defroster on too which in turn cycles the ac and I can't remember but I think the ac on also signals the iac open. Good luck
 
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