60 won't idle until warm (1 Viewer)

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Nov 29, 2016
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82 FJ60. Aisin carb. All smog components present.
Recent purchase.

Stumbled under load periodically on the way home. 150 miles. Topped off tank half way since gas gauge is inoperable. Assuming either vacuum or carb issue. Had been driven very little in the last few years.

Before I could start mapping/testing the vacuum lines, it developed a new problem that may be obvious to someone with more 2F experience. Now that's it's cooler, it will crank right up but won't idle without holding the gas and rpm at about 1500. The choke has no effect. Once it reaches operating temp, it will idle at 1k rpm. I can pull the choke and it will idle up at that point so it's working. I can shut it down, fire it back up and idles at 600rpm just fine.

So...I can keep it running when it's cold via the gas pedal but not the choke (doesn't run particularly smoothly). Will idle fine when it reaches temp and choke functions then.
Bad BVSV all the sudden?
Totally unrelated to the stumbling?
 

g-man

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intermittantly?? Bad fuel? Pull the fuel line off the carb, crank the motor and have a friend catch some fuel out of the line with a mason jar. Look for water in the bottom. WAS the truck sitting for a long time before you purchased?
 
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Have a new fuel filter ready to go on so checking the fuel quality is a good idea. It was driven monthly but fuel delivery needs to be looked at for the hesitation issue. The no idle when cold is different. It smoothes out once the engine reaches operating temperature and the choke appears to have no effect until it reaches operating temp. Those 2 symptoms have me curious about the BVSV but it seems like an odd part to fail. I’m thinking it’s more carb related but I don’t have a logical explanation.
 

OSS

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If the carburetor hasn't been rebuilt in about ten years or so, it likely needs it. So if that's the case, get that done (since it should be done anyway). Also if the manifold gasket hasn't been replaced in that amount of time either - that should be done too. They wear out. When the manifold comes off, check it carefully for warping. Setting it on a glass table, ports down while examining all seals against the glass is the easiest way to find out if it's warped or not. Every 2F manifold that has never been machined before will have some warpage. Warping creates vacuum leaks.
Get a vacuum gauge and check at idle with cold engine & hot.

But a vacuum leak doesn't affect driving acceleration - there's no vacuum when accelerating. A vacuum leak will make starting and idle when cold difficult. When the engine heats up, metal expands and can seal off a (manifold) vacuum leak. Also a hot engine can run on a leaner mixture (vac leak) that a cold engine.

Get that vacuum gauge.
 

mongoose2231

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I want to make one suggestion, before you do anything. Get some seafoam and seafoam your truck. Pull the fuel line before the pump and stick it in a seafoam bottle at 2500rpm. Suck the entire thing through the carb. I had a similar issue, the truck stumbled and did not idle after I replaced all the vacuum lines under the hood. I tried everything, including resurfacing manifolds. I then did the simplest thing I could have done to begin with. And that is seafoaming the carb. Fixed the problem!
 

CaptClose

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To add to @OSS great advice... get a feeler gauge and CAREFULLY examine all the edges against a glass table (or other known flat surface). The tollerances are so tight that it will likely fool the human eye into thinking “ehh.. That’s close enough”, and it might be close enough... for a few months. Then you’re ripping everything apart again to do it right the second time. I speak from experience.

C4EF7164-2D98-4B03-B8EA-6775DC233EE5.jpeg


Of course, try the seafoam and other easy remedies first, and see what happens. But OSS is right, if your carb hasn’t been rebuilt recently, or your manifolds resurfaced... it won’t take a Nostradamus to tell you what your future has in store for you. So just do it anyway.
 
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morganism

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There are only a few really overriding issues that pop up with driveability or electrical probs, and you want to try the low tech ones first.

#1 for 80's Cruisers is a sticking EGR. Put a spare piece of vac line on the top hat of the EGR, start truck, and tap on valve body why sucking and releasing vac with your breath. It should nearly stall, and listen to hear if rocks fall down into your oil pan. If wont stall, then EGR jammed, if rock fall, or no rocks, then you don't have to mess with it anymore. Now you can concentrate on vac leaks.

Of all the times i have seen folks here replace fuel pumps or sock filter, i can only remember a couple where that was actually the problem, and it usually was rust in tank or lines that was the actual prob. Now if you have FPR and injection, you have a diff set of regular probs. With 2f's it is usually changing fuel filter injects crap into the float bowl, and causes plugging jets (especially going uphill).

There are also some things that don't get caught easily, like the distributor set pin that only the experts know about, that will cause heartache, and a noticeable lightning of the wallet, as you try to chase down gremlins.

"Read this thread!!! If you want to mess with the stop bushing this thread gives part numbers for a replacement pin: Both aluminum and plastic 1/4" OD x 1/4" length and #8 screw size are available."

Dizzy FAQ
 

morganism

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dang, NoScript really doesn't like the scripts here.. can't even post sometimes, let alone edit.

the first question about hard steering in reverse tells me your idle prob set correct, and air/fuel mix prob not tampered with. Gearing and low accel under torque and PS cranking show up easily there.
 
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Picked up a spare carb and manifolds last week. Rebuilt carb and ready to go on. Figured I might as well machine manifolds and have them ready to go as well. Take existing set up off and bolt refurbished set up on.
 

Trapper50cal

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A good cheap way to identify if you have an intake manifold leak is to spray
brake cleaner around the ports while it's running...if the idle rises or smoothes
out during that process, you have a leak.
 
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Hooked vac gauge. She cranked up and idled normally w 20in. (Typical situation when I’m trying to diagnose a problem.) Sprayed carb cleaner at manifold/head. No change in idle but plenty of white smoke out the exhaust.

Still hesitated like crazy under load. I’ll stick rebuilt carb on and see what happens
 

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