Help: 3FE Terrible Idle and Misfires after dead battery (1 Viewer)

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big island, hawaii
Post deleted.. on further thought, what I wrote seems extremely unlikely and probably more distracting from actual issues than helpful.
Hey! All suggestions are helpful. It seems like the rough idle/driving but barely is a common symptom of many different underlying problems
 
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Dec 8, 2006
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New Jersey
I replaced the spark plugs and wires today. The old ones looked BAD.

I tightened the throttle cables and now have an idle in park at 1200. It drops to 700 in drive or reverse, but still has major issues transferring any power to the drive train. Doesn’t seem to be popping/misfiring like before, but I haven’t tried driving it so much. I’ll know soon.

I need to use the truck today to pick people up from the airport. Not sure exactly what to do or if I need to get a taxi and then rent something until I can get this figured out. I managed to do a 4 hour round trip drive yesterday (it was weaker than usual on the highway but still ran, in town it was SLOW), but the truck died when I got home. Started up this morning and I’ve been doing what I can do with what I have on hand.
Your throttle cable is too tight. Idle speed should be 650 at normal operating temp.
The correct way to adjust the throttle cable is to have someone push the pedal to the floor. The throttle plate should just touch the end stop. With the pedal released there should be some slack in the cable. Idle speed is set by the ECU and ISC valve.

Getting the factory service manual would be a great first step for you, as everything you've mentioned is explained in agonizing detail.
 
Joined
Sep 2, 2020
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Lodi, CA
Maybe check the vac diagram under the hood?
Check that your hoses are going to the right places. When I was replacing mine I found most were cracked or hardly snug to the hard line nipples.
If your PO was messing with something he may have got too much air- needed more fuel- tightened the cable- and bypassed the efi to get as much fuel in the cyl as possible?
Just a thought- I do not know nearly as much as Jonheld so take this with a grain of salt.
 
Joined
Mar 11, 2021
Messages
40
Location
big island, hawaii
Maybe check the vac diagram under the hood?
Check that your hoses are going to the right places. When I was replacing mine I found most were cracked or hardly snug to the hard line nipples.
If your PO was messing with something he may have got too much air- needed more fuel- tightened the cable- and bypassed the efi to get as much fuel in the cyl as possible?
Just a thought- I do not know nearly as much as Jonheld so take this with a grain of salt.
Thanks! The vacuum lines are right and I have the service manual, but I think the egr is clogged and I’m deleting it. The intake is bad and replacing that too.
 
Joined
Mar 31, 2021
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akron ohio usa
Your throttle cable is too tight. Idle speed should be 650 at normal operating temp.
The correct way to adjust the throttle cable is to have someone push the pedal to the floor. The throttle plate should just touch the end stop. With the pedal released there should be some slack in the cable. Idle speed is set by the ECU and ISC valve.

Getting the factory service manual would be a great first step for you, as everything you've mentioned is explained in agonizing detail.
Can you link the engine fsm for the fj80? I can only find chassis....not engine. Trying to solve rough idle and cannot find what factory idle is in my searching. Thanks
 
Joined
Jun 26, 2013
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Charleston SC
I second the agonizing part that jonheld mentioned, but well worth it. I am using the FSM to troubleshoot my MAF. Absolutely priceless since a reman MAF is pricey. Get a FSM.
 

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