Runs smooth then idle is up and down and sometimes dies.

[Fisher]

My FJ60 is usually a great runner, just set the timing, replaced plugs and wires, replaced all old vacuum lines and fuel filter. Every once and awhile whether cold, warm or hot I get this wierd idling issue, it's been haunting me for years. Seems to happen when I let off the gas before I pull in the driveway or at a stop light or when I need to back up to put the fishing boat in the water. (but I also can tell it's happening if I'm driving fast as it feels rough at top speeds when driving 55 or 60-not super rough but enough to be able to notice a difference)

It either wants to just die or the idle will fluctuate and jump between 1500 rpms to almost zero and then back again . If I try to keep it steady by feathering the gas it just sounds rough and is almost impossible to keep steady. But then out of nowhere it will get happy agian and be just fine. Like something came loose and the fuel is flowing again. I don't know...

If anyone could help with this one that would be awesome...
Thanks

 

[hammer1]

Same thing for me. for years, my 60 has had the exact problem. I went as far as to replace the carb with a NEW OEM, not even a re-built. it helped a little bit. Complete tune up does not help. In the winter time, or when the temp goes below 45, the truck will ONLY run with the choke pulled completly out. I have no idea what to do next. it might be that it needs a vavle job, which I cat do, and at this point, cant afford to have some one do it.

 

[lathrop]

sounds like a flaky sensor. No idea which one. I just replaced my Carb. [ it needed it] and my ecc. Ran beautifully for a month till I went on a couple of 200 mi. runs. now it Idles like s***. And the Vac. is low. These things have an huge # of vac sensors and modulators. Which one is the problem? Which one is the culprit. Wish I knew.
Lathrop

 

[Fisher]

Interesting guys... I actually had a valve job done and it didn't help with the problem although , acceleration was much smoother. I would LOVE to figure this one out though....

 

[fliphkd778]

My first two suspects would be the EGR valve and the VCV valves. If you need description on the manual tests, I can help you out. I had a very similar problem in my wagon for a long time. It turned out to be a bad VCV.
-Here is the write up. There are even two videos of my truck acting up, maybe you could see for a comparison.
https://forum.ih8mud.com/showthread.php?t=173040&highlight=$800

 

[Fisher]

I'd love to try the tests in the morning...if you have tips on the tests I'll go for it and get back to you.
Thanks for the info!

 

[High Desert]

Mine did this too, would just starve out and shut down at the first stop after long hwy cruising.

1st thing I did was by-pass the egr. This stopped the surging I was having..the rough and varied rpm idle issue did not stop, until: I changed out all the vacume hoses. The hoses on the carb next to the air rail were cracked and brittle, two were broken almost in-two. I also shot a whole lotta carb cleaner in the nipples on the carb. No more problems since.

already done all this?..Oh well then, gee, I dunno...sorry

 

[Fisher]

Ok..here we go agian. For the past few days since I changed all the vacuum hoses, plugs and wires, reset the timing, seafoamed the carb and gas tank, the 60 has been running great. No stalling while idling at all. So I'm driving down the road at about 35mph and I feel a slight hesitation like it's either not getting fuel or it's missing. So I push in the clutch to test if it would idle or to see if it would just just stall out. And it just died. So I just rolled for 50 yards and popped it back in and it fired right up and the episode was over, idling fine. What in the world is this problem?

Thanks guys

 

[FLA60]

Do you have an in-line fuel filter? Perhaps fuel filter is clogged?

 

[sirzepp]

Mine is doing the EXACT same thing. It'll run fine...then not idle...stall...I'll restart it...and it will run fine again for a while...then do it again.

I'll check my VCV's and EGR.

 

[sirzepp]

I swapped the VCV's and now it idles smooth...we'll see if that continues. I guess just the one VCV needs to be replaced if it does...EGR works great(when I tested it, though I don't think it's going to work now that swapped the broken VCV over?).

 

[hammer1]

I will have to try the vcv replacement. Anyone know the part number, Toyota or SOR?
Thanks