Weird short term idle problem in traffic

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caladin

Noob, but trying to learn
SILVER Star
Joined
May 30, 2011
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Location
Pflugerville Tx
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Took my 60 to go see the Dr. 70-75 (82 4speed 33s) both ways 30 min run. Made several similar and longer runs over the last 2 weeks, nothing special. Try to stay 5 to 10 mph below, speed limit so I'm at the bottom end of legal. Gauges all looked fine the whole time.

On the way back, put in the clutch exiting the highway to stop at traffic for first stoplight.

Idle slowed down and died while I was coasting to a stop clutch fully down. .

The in traffic she wouldn't start. Pumped the Gass,, Pulled the choke nothing worked, not even a sputter. , Hit the hazards and waited on the light. She usually starts on choke cold in a few seconds, and effortlessly warm.

Put her in gear was going to use the starter to creep her onto the shoulder, but she started after a few seconds of non stop cranking, maybe 5 feet of movement... choke was still out so idle was high, pushed it in and really rough low idle, with decreasing RPM, trying to stumble and die. Start above 1k quickly stumble down below and try to die, used choke and later accelerator to keep idle up and limped her home, maybe 5 min at speed 25-50. All gauges looked fine before, during and after.

Volt meter was barely above 12v on starter battery circuit when running.

By the time I was home, the idle was fine, rock solid, restart was fine, issue was gone.

Been replacing vac lines lately mostly one at a time , so I can't mess it up. only a handful left to do. Found a bunch of lines that were not hooked up. Fixed those as I went.

part way through vac lines, started to have a occasional stutter taking off at stop signs with low rpm, but otherwise runs OK. Maybe she's running worse, maybe im getting lazy with engine RPM. Been running shell premium since this started to get any gunk out and she runs, a hair better .

When I got home Engine compartment was very hot, even the fender uncomfortably hot to the touch. Engine temp gauge never left the middle, (maybe it's not accurate?) .

Noticed I never hear the carb fan when I shut off truck, as I did with my previous 60... So maybe vapor lock when she died in traffic? can that cause rough idle? but I still have no idea why did she die? Shouldn't vaporizing Gas cool it back down in seconds once it's running?

My thoughts are either
Gunk in my carb idle passage that cleared itself, or something heat related, as I'm in Texas, and was in traffic at highway exit. but temps, are below 90. Last summer she, was not reliable enough to drive consistently.

Going to get radiator cap with thermometer and validate temp gauge. Going to see if i can get more accurate readings of engine compartment temps.

Have a 10 micron fuel filter I was going to put as close to carb as rubber goes.. To catch any gunk going to carb. Is it all hardline from just after fuel pump to carb? That's all I see...

Any ideas what else I should check? Or what might be the issue? I'll go over the vac lines to be sure I didn't mess anything obvious up... Anyplace I should check first? Had to glue altitude comp valve, and one of the low temp idle switch's back together with straws in the nipples, but neither seems to apply here.
 
I had something like that happened a few weeks ago on my FJ60. It acted like it ran out of fuel. I towed it home, added fuel and it started up. The fuel gauge was reading 5/8 of a tank. So I figured the gauge sending unit was bad. I pulled this out and sure enough it was rusted stuck and so was my fuel tank. I ended up draining the rusty fuel out, pulling the tank and having it cleaned by a radiator repair shop. By the way, I drained more fuel than I added so the rusty fuel caused by issue. A clean tank, fresh fuel, quick carb cleaning and new hoses brought my truck back to life. I hope this helps.
 
If your cruiser is still running all the smog equipment- I bet the EGR valve got stuck open - then eventually snapped shut on its own after awhile.
Hook up a vacuum gauge that you can see in the cab when seated.
The next time the engine pulls those shenanigans, take a look at the vacuum gauge.
 
I saw a thread using these to modulate the EGR, and realized I think i left mine off when i hooked things back up, at least I don't see a white one anywhere only a black one in the location of the top red circle...

(test location is the bottom red circle that I thought was original location, confusing me)

But i half way remember a white one when I was replacing vac line.... Are there another places I should look for a white one other than the top circle? I can't see any on the diagrams


1714603697375.png



Where else should i see one of these restrictors?

Also I appear to be missing the blue restrictor/valve the arrow is pointing at which is vac advance, so seems suspicious..

1714603970523.png


Could that contribute to the issue?

I pulled and blocked the hose going to the EGR to disable it, per another thread, and am going to try driving it. To see if the EGR is part of the issue.

Since it might be sticking and un-sticking i'll probably pull and clean it anyway.

I straw+glued the violet BVSV back together, but it's only a low temp idle up, so if it's malfunctioning, it should have nothing to do with this issue

Same with the HACV, i Straw+glued it back together, but I'm close to sea level (700-1k feet above) so it should not matter.

Right?

Thanks,

1714603629016.jpeg
 
Something similar happened to me a few months ago and it took me a while to narrow it down to the simple thing: Fuel Filter.
 
There's a million things it could be, but to start for your understanding, you had an issue with air/fuel mixture at deceleration. Instead of guessing, it is time to run through the emissions system.

1. The vacuum restrictor to the egr should not be there, remove and install new piece of vacuum hose. I see the vacuum restrictor is already in place on the correct hose to air cleaner. There is technically only one restrictor in the system and you have it installed. Make sure it is not backward btw.
2. Verify your emissions computer solder connections to the terminal are reflowed and not cracked, this is a major overlooked item that plagues these trucks.
3. Measure vacuum at idle and see what it measures when hot and cold, report back.
4. After all that, depending on outcome, run through the emissions manual for every item and you must ensure all vacuum lines are correct, no guessing.
5. @OSS is right, it is good to check the EGR manually by putting a long hose on the top vacuum port while the truck is running and suck on the hose to actuate the valve. If the truck stutters and dies, the egr is working correctly. I've had one instance where it was stuck open a little and it caused stalling issues, cycling it open then closing resolved.
 
I’m down the road from you in Sunset Valley if you want to swing by. I’ve got a bin with all my smog stuff in it that I pulled off. I’m pretty sure I don’t/didn’t have a restrictor like that though.

But I’d listen to @mattressking, he knows what’s up.
 
Something similar happened to me a few months ago and it took me a while to narrow it down to the simple thing: Fuel Filter.
I did just replace the fuel filter with a new one, because the old one was cracking... Maybe I need to get an OEM one, i just used a BeckArnley I had on hand

It's smaller than the previous one, and a hair smaller than OEM but I'd think that would affect it as higher RPM, not idle. Curious.

For those who read this thread later, the 82+ filter is the part # below, at the time of posting it's $9ish from Toyota parts deal.(plus shipping)

23300-38010​

23300-38010 Genuine Toyota Fuel Filter Assembly - https://www.toyotapartsdeal.com/oem/toyota~filter~assy~fuel~23300-38010.html

And is available from amazon for $14
https://www.amazon.com/Toyota-23300-38010-Fuel-Filter/dp/B00KTJA2UU
 
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Probably not the filter, then.
 
There's a million things it could be, but to start for your understanding, you had an issue with air/fuel mixture at deceleration. Instead of guessing, it is time to run through the emissions system.

1. The vacuum restrictor to the egr should not be there, remove and install new piece of vacuum hose. I see the vacuum restrictor is already in place on the correct hose to air cleaner. There is technically only one restrictor in the system and you have it installed. Make sure it is not backward btw.
2. Verify your emissions computer solder connections to the terminal are reflowed and not cracked, this is a major overlooked item that plagues these trucks.
3. Measure vacuum at idle and see what it measures when hot and cold, report back.
4. After all that, depending on outcome, run through the emissions manual for every item and you must ensure all vacuum lines are correct, no guessing.
5. @OSS is right, it is good to check the EGR manually by putting a long hose on the top vacuum port while the truck is running and suck on the hose to actuate the valve. If the truck stutters and dies, the egr is working correctly. I've had one instance where it was stuck open a little and it caused stalling issues, cycling it open then closing resolved.
The images above are from a thread where they used the restrictor to moderate an worn out and over easily reacting EGR. Not mine. I only have the top restrictor but it's black not white.

I suspect the Black restrictor is a replacement the one I circled at the top, and it's in the correct place. I'm going over the Vac diagrams carefully checking things over.

The Missing blue vac valve is still available from Toyota, so I just ordered one.

I just did the disconnect the EGR test and the stumble off the line is still there. If I disengage the clutch at lower RPM, it lurches or bogs till the RPM comes up. This is annoying but easy to compensate for, just more rpms off the line. It's the first symptom I had of any issues, and the other issue was intermittant, so I'm assuming it's a proxy for the other issue.

The EGR could be leaking as you describe. Is sucking on it enough to actuate the valve? I was waiting for a hand vacuum pump to arrive, as my other one is 90 min away at the ranch wit my brake bleeder kit. Didn't know that was enough suction to actuate it.

I'm going over the Vac diagrams carefully, trying to ID issues and solve them one at a time. The fact the troubles started when I was replacing the hoses points to a mistake on my part. That said, that's also when I started actually driving it all the time, as it was finally healthy enough to do so.(I thought)

Thanks,

Eric-.
 
I was just able to suck hard enough to kill the engine, it seemed to actuate pretty easily and smoothly. Not sticky at all.

Drove about an hour and it did not repeat.

Will still pull and clean it, for supposed improved performance if nothing else, not much get up and go at the top end, I'll take every drip I can get.

Blue valve now Not available anymore from Toyota, order canceled, so I picked two new up on ebay from the UAE. Cost about the same
 
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Yeah a simple vacuum hose restrictor that blocks air flow equally in both directions- isn’t going to help an EGR valve that occasionally sticks open after highway running. Actually it’ll encourage the problem to happen more frequently.

You want one of those Toyota dual colored VTV valves (like you ordered) because they restrict the airflow in the pulling direction but allow full air flow in the other. That allows the EGR valve to snap shut quickly and easily. A simple restrictor makes the EGR valve slowly close which can make sticking more likely.
 

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