FJ60 "Classic Stumbling Issue" - EGR Valve?

[ravenplague]

Wanted to report good results with a stock restrictor valve between the modulator and EGR diaphragm.
You can see the same restrictor in the stock location top center of the first photo. I had a spare one from another 60 in the driveway.
I tried a blue VTV (black end towards modulator) but it just felt like the EGR was disabled, which makes sense because the blue VTV is very restrictive but will release the vacuum built up immediately. So I'm guessing the blue VTV doesn't allow enough vacuum to be built up in the EGR valve before the modulator releases it?

This white restrictor will dampen the flow of air in both directions so it'll slow the opening and closing of the EGR valve.
Which is exactly how it felt during the test drive- I could feel the EGR kick on but it wasn't causing the car to lurch back and forth. It felt much more subtle as it opened. My issue was so severe and annoying it felt like the clutch was starting to slip @ 2k. Now it feels like a subtle emissions power rob.
I was beginning to wonder why anyone ever bought these cars new- all my emissions equipment systems passed the tests. My only other driving experience with a 60 was desmogged.

To anyone experiencing this issue, try this!
Sucks that these valves are NLA.
If you steal one from your stock location, you'll need to find something else to go there (a spare VCV would work, blue towards air cleaner) because this circuit is a controlled small vacuum leak that you'd be making into a medium vacuum leak if you remove the white restrictor.


View attachment 3617308View attachment 3617309

Where can I find the white vsv on my fj now to try this out?

 

[iansplatinum]

Where can I find the white vsv on my fj now to try this out?

It's spliced between one of the three vacuum hoses that go to the top three nipples of the air cleaner near the mouth of the carb. It's a simple little vacuum connector with a hole the size of a tack needle. It's job (from what I can tell) is to limit the size of the vacuum leak into that circuit since it is technically open to manifold.

Don't get me wrong, the deadzone is still there, I'm guessing that's just the nature of EGR on this engine. But now its not so disruptive and concerning feeling. Now it feels more like I'd think it's "supposed to" feel.

Nothing is the same as flat out disabling that EGR valve though!

 

[Spike Strip]

This is one of those bits that has many names: flow restrictor, miniature orifice restrictor, etc. And of course, Toyota just calls it a 'Way'...

McMaster sells these in SS versions and various rates of restriction. Various online places sell plastic versions, called Miniature inline Orifice Restrictor.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Miniature Inline Orifice Restrictor

Inline Orifice Restrictor, .020 Orifice, 1/8 ID Hose Barb X 1/8 ID Hose Barb, Blue Polysulfone Body

www.universalpowerconversion.com

 

[Chris Cahill]

I really wanted to keep my 60's stock over the years but I finally gave up after fighting the same issues you describe. A full desmog of all 3 using Jim C parts turned them into reliable, solid runners with no more issues. I did not recurve the distributors and they do fine as is IMO. That's not to say that a recurve could improve performance. I understand desmog is not an option for everyone ...

 

[DFXR]

thread bump. Can you detail this? is the valve on/off or does it restrict the flow? Which hose? There's a larger hose going from the bottom of the modulator to the J pipe, and there's a smaller hose going from port P (or Q?) to the EGR opening diaphragm. seems like either might work in reducing the speed at which the EGR opens, or delaying when it opens in general.

Does anyone have any data on what amount of vacuum the EGR is supposed to open? Mine does with around 3-5 inHg.
Tried swapping moduluators and VSVs, both pass the test but my EGR is causing a major deadzone 1.8k-2.5k

See below:

The Classic FJ60 "Stumbling/Hesitating Acceleration/Running Problem

forum.ih8mud.com

Post #212

I’ve been using the black and white Ford/Motorcraft vacuum delay valve (still available as NOS, and cheap) for a few years now. No stumble, no issues passing smog, visually or at the pipe. Watching the emissions numbers with the truck on the smog shop rollers, I can see when it kicks in. Roughly a couple second delay and that’s just enough to get past the stumble without getting too lean. Also, it looks right at home in the engine bay.

 

[RDub]

@Jasonredwood
@FJ40Jim

The FZJ80 EGR vacuum modulator works perfectly on the FJ60 2F. It snaps right into the little spring bracket too. The only difference is the vacuum pipes are pointing at a different angle - but no biggie, just add a slightly longer piece of vacuum hose.

LUCKY for anyone who might be interested... It'still is available new from Toyota or on eBay.

Below shows a picture of it in the 60. Passed smog test fine. My EGR valve was working normally (but I went through a few to find a good used one)

Drum roll ..... PN: 25870-66011

View attachment 2201905

Resurrecting an old post. Does anyone know at what vacuum level a “good” EGR valve should open? I have the EGR stumble badly, including a random stumble at cruise with part throttle. I ordered the FJZ80 modulator and the Ford VTV, currently waiting for them to arrive. I do know my EGR valve opens almost when I just look at it (barely moves the needle on my hand vacuum pump/gauge and opens right up, on the lower side of 2-5 mmHg), so I will need to experiment when the parts arrive. Just curious about the valve specs in case I end up needing to chase down a good used one. Thanks.

 

[OSS]

The EGR valves wear out over time and open too easily and quickly. They aren't available new anymore (or for the last 15 years). I have gone through 6 different used valves and they were all like that. They are wear items and definitely wear out past spec.

The easiest workaround that doesn't cost any money is just don't pussy-foot the throttle. Step on it with authority. It won't waste any more gas doing that because the EGR valve is creating a big anoxic vacuum leak.

Step on the throttle deeper. No more light throttle.

 

[RDub]

The EGR valves wear out over time and open too easily and quickly. They aren't available new anymore (or for the last 15 years). I have gone through 6 different used valves and they were all like that. They are wear items and definitely wear out past spec.

The easiest workaround that doesn't cost any money is just don't pussy-foot the throttle. Step on it with authority. It won't waste any more gas doing that because the EGR valve is creating a big anoxic vacuum leak.

Step on the throttle deeper. No more light throttle.

Thanks. I have done that when accelerating, but it won’t help the stumble at cruise. Im hopeful the new modulator valve and possibly the Ford delay valve on the line to the EGR valve will help that. It’s really more of an issue passing emissions testing right now.

I also need to verify the VSV and computer are working properly. The VSV is “new” and tested good a few weeks ago before the stumble got really bad, but I need to go through all of the emissions manual tests again.

Sorry to go on and on here. I rebuilt the carb a few weeks ago to cure a rich running issue. The truck ran great afterwards, no more richness and the EGR was connected with no stumbling. After an hour or so drive I shut it off and went through the distributor cap and wires, just making sure all were clean and pretty. After doing that I started it up to go for a drive and the stumble appeared out of nowhere. At the same time I noticed the voltage gauge was running lower than normal. I replaced the voltage regulator and it seemed to fix the voltage but the stumble stayed. It's a really bad stumble, almost undriveable. It runs fine with the EGR valve vacuum lined disconnected and plugged. So something changed. That is why I feel the computer needs checking. Any other thoughts on things I should check?

 

[DFXR]

Thanks. I have done that when accelerating, but it won’t help the stumble at cruise. Im hopeful the new modulator valve and possibly the Ford delay valve on the line to the EGR valve will help that. It’s really more of an issue passing emissions testing right now.

I also need to verify the VSV and computer are working properly. The VSV is “new” and tested good a few weeks ago before the stumble got really bad, but I need to go through all of the emissions manual tests again.

Hopefully the VTV solves it for you. It definitely did for me. The next step for me was going to be the 80 series modulator but once I got the VTV in line the stumble was gone, and has stayed gone for quite a few years now. Glad to have saved that $90 or whatever the 80 modulator is. I had already spent time and $ on a used EGR valve as well as a couple used VTVs, without any of them solving the problem.

As you pointed out, driving with the stumble was one thing but getting through the smog test was the real headache since the techs struggled to hold 15/25 on the rollers with the stumble happening. Unless they were super cool (rare) they would just throw up their hands and say “can’t do it.”

I have passed 3 CA emissions tests with the black and white Ford VTV in place and it has not been an issue at all. It looks like it belongs there. Try the VTV before you try the 80 modulator.

Good luck-

 

[RDub]

Hopefully the VTV solves it for you. It definitely did for me. The next step for me was going to be the 80 series modulator but once I got the VTV in line the stumble was gone, and has stayed gone for quite a few years now. Glad to have saved that $90 or whatever the 80 modulator is. I had already spent time and $ on a used EGR valve as well as a couple used VTVs, without any of them solving the problem.

As you pointed out, driving with the stumble was one thing but getting through the smog test was the real headache since the techs struggled to hold 15/25 on the rollers with the stumble happening. Unless they were super cool (rare) they would just throw up their hands and say “can’t do it.”

I have passed 3 CA emissions tests with the black and white Ford VTV in place and it has not been an issue at all. It looks like it belongs there. Try the VTV before you try the 80 modulator.

Good luck-

Thanks! That gives me more confidence. Both the 80 modulator and the VTV are arriving at the same time so I will experiment both ways. I bought the 80 part from Partsouq for $65, along with a bunch of other small items to make the $27 shipping charge worthwhile.

I’m in Colorado in an emissions testing county (Boulder), and Colorado has adopted the CARB standard for replacement Cats, which I also need. Mine is original and definitely not working. I have the Magnaflow CARB Cat on order. So I have a few things to replace before testing again for the sixth time. Almost made it through last time by setting timing at 4 degrees BTDC and disconnecting the HAC at the distributor diaphragm. Got HC down but NOx was high because the EGR was not connected. Imagine how bad the stumble is at that timing with EGR connected!

 

[ravenplague]

Thanks! That gives me more confidence. Both the 80 modulator and the VTV are arriving at the same time so I will experiment both ways. I bought the 80 part from Partsouq for $65, along with a bunch of other small items to make the $27 shipping charge worthwhile.

I’m in Colorado in an emissions testing county (Boulder), and Colorado has adopted the CARB standard for replacement Cats, which I also need. Mine is original and definitely not working. I have the Magnaflow CARB Cat on order. So I have a few things to replace before testing again for the sixth time. Almost made it through last time by setting timing at 4 degrees BTDC and disconnecting the HAC at the distributor diaphragm. Got HC down but NOx was high because the EGR was not connected. Imagine how bad the stumble is at that timing with EGR connected!

Do you mind trying each separately and reporting back?

What is the part number for the black and white Ford vtv?

Thanks !

 

[RDub]

I’ll be glad to test each separately and report back. The Ford part number comes from @DFXR in another EGR stumble thread he referenced earlier in this thread. This is from his post:

There are several for sale on eBay, most are NOS.

 

[OSS]

Toyota still sells different VTVs

 

[RDub]

Toyota still sells different VTVs

I’d prefer to use a Toyota part but for this round I’m leveraging the work @DFXR has done with the Ford part. Is there a way to compare the specs between the Ford and Toyota VTVs? I haven’t seen a way yet, but others probably have done more research.

 

[DFXR]

Toyota still sells different VTVs

Yes, they do. Definitely weird adding a malaise-era Ford product to a Toyota. But the EGR's a b**tch. I'd put a Jeep valve in there if it worked. And I think these Ford valves were originally added to deal with EGR issues just like ours.

You know what else works? An little plastic inline valve for drip irrigation, with the flow control dial and barbed ends on both sides. Fits the vac line perfectly. You can even customize the flow. But since it never actually opens up fully, it's probably not a good long-term bet.

I was hoping originally to keep it Toyota but had a hard time finding the correct VTV. The NOS Toyota VTVs tended to be much more expensive, too.

 

[DFXR]

I’d prefer to use a Toyota part but for this round I’m leveraging the work @DFXR has done with the Ford part. Is there a way to compare the specs between the Ford and Toyota VTVs? I haven’t seen a way yet, but others probably have done more research.

Here's the Ford/Motorcraft chart. I don't remember finding a Toyota chart that made sense, or maybe i did but then couldn't find the actual valves. Someone might have one.

 

[OSS]

I’d prefer to use a Toyota part but for this round I’m leveraging the work @DFXR has done with the Ford part. Is there a way to compare the specs between the Ford and Toyota VTVs? I haven’t seen a way yet, but others probably have done more research.

Attached below is a chart of all the Toyota VTVs (as of 1986 Landcruiser manual) with flow rates and color designations --- and part numbers.

 

[OSS]

VTVs restrict the flow of air going one way but let it freely flow quickly the other direction - which is what you'd want for EGR valve delay. A simple restrictor will slow down the vacuum flow both directions -- so when you take your foot off the gas pedal, the EGR would be slow to close or get stuck open if its old & cruddy

 

[ravenplague]

I’ll be glad to test each separately and report back. The Ford part number comes from @DFXR in another EGR stumble thread he referenced earlier in this thread. This is from his post:
View attachment 3836491
There are several for sale on eBay, most are NOS.

Just ordered one...out of curiosity, how should this be oriented?

 

[RDub]

Just ordered one...out of curiosity, how should this be oriented?

From @DFXR: