62 stumble at low speed (1 Viewer)

[Cnut]

Just got a new issue yesterday. Truck was running fine/normal - stopped somewhere - got back in, cranked up, and noticed it stumbling at an intersection. Especially at low speeds, it is running rough. At about 22mph it seems to break free and run better, but I still notice intermittent stumbling at higher speeds. Idle, which has been great, now has a stumble (momentarily rough & drop in rpms) every couple of seconds. I've replaced the fuel filter, dropped sea foam in the tank (thinking possibly bad gas), and have ordered new vacuum hoses. Air intake appears okay, but will inspect it more thoroughly this weekend. Any other places to look?

I find it odd that it came on all of a sudden after cranking the car - like something failed somewhere. Until then, idle and power were fine.

 

[89BIGBLUE]

Watch for a check engine light...
Go over vacuum lines.
(I found a rust out hole in the hard vacuum lines to the transfer case that once fixed, seemed to help even her out.)

Hope this helps.

 

[Randy88FJ62]

I second the vacuum lines and air intake. Check that you don't have any cracks on your two soft ribbed intake hoses going from your air cleaner to your intake manifold/MAF.

How is the idle when in park?

 

[morganism]

Anytime you get a "new" rough idle, check the EGR first. Rocks get stuck in it, and block it open.

 

[Super77]

This help?

Check your air intake hose if you have rough idle

 

[Cnut]

Replaced most vac lines today. Smoking hot outside, so I stopped short of 100%. Haven’t driven it yet - but will be later and will report back. PO had new MAF installed along with new hoses to the intake. They still look good, but I will inspect closer if the vac lines, which were original and needed replacing anyway, don’t do the trick.

F everyone’s I, the washers that came with my new fuel filter would not allow a proper seal. I ended up with a slow leak for a day and the need to repaint the engine side of my wheel well (gas eroded the paint). Switched back to the old washers from the bottom of the trash can and am now leak free.

 

[Cnut]

Knock on wood. New vac lines seem to have it back running smooth