EGR Vacuum Check Valve (Photos included)

I replaced my EGR valve vacuum check valve, but now started getting sputtering/rough idle.

I’m pretty sure the direction of the vacuum check valve is correct, but I tried both ways to be sure and still got the sputtering at idle.

The old vacuum check valve didn’t give me the sputter. I only replaced it because it was melted and I’m not sure it was working. I included a photo of it. It’s orange and black.

Well of course the first guess would be you got the wrong check valve or a faulty check valve. How to czech a check valve, there may be different paramaters for different cars. I would try taking it back for a refund, and buy the replacement from a dealer,

It might be a faulty replacement as Barky says. You could try blowing on it from both sides. Usually check valves – if they are working properly – will flow one direction, but not the other. Do the same thing with the one you took out. Might provide a clue. And make sure the hoses that connect to the check valve are making a good seal. Sometimes the hose ends will enlarge, and create an air leak, which will cause the checking function to fail to work correctly. Might be worth it to replace the hoses while you are at it. Good luck.

What purpose does a check valve have in the operation of the EGR valve? In one direction it would prevent the valve from opening, and in the other direction it would prevent the valve from closing.

RK hit the nail on the head…I don’t think the gizmo you replaced was a check valve. It might have been a flow restrictor used to modulate the action of the valve…

At idle, there should be no vacuum signal to the valve as it should be closed…If you feel the rough idle is EGR related, you should remove the valve and check its operation…

Another vote for Rod Knox.

You did not state what year model Corolla this is but after taking a quick look at ALLDATA and one of my manuals, they do not show a check valve for any Camrys and so on. I would expect a Corolla would be similar.

The only vehicle with any sort of EGR check valve that I can think of off the top of my head is the old VW Bus and it was a vastly different type of valve with an electrical input.

It’s a 1989 Toyota Corolla SR5 coupe carburetor and automatic transmission.

I’ve been looking around online and can’t find that part online. Honestly, I just brought the part into Autozone and asked them what it was. They directed me to the vacuum check valve. I can’t find a check valve that belongs near the EGR valve so it’s something else. Now I have to figure out what.

Thanks for all the help so far guys, really appreciate it. I couldn’t find much about it online and I think you guys figured out why because I shouldn’t be searching for a vacuum check valve probably.

Okay, it’s definitely a valve check.

Found it here, part 23285A Valve:

and this is in a Toyota truck:

My literature does not provide any testing procedure on a Toyota this old. That valve is referred to as a “valve” but it also does not use the word check to go along with it and that could make a difference.
The vacuum lines are also routed through an EGR solenoid which is also referred to as a valve.

I’ll rummage around on ALLDATA a bit more and see if I can come up with test procedures for this.
Back in the old days a mechanic might wander over to the toolbox and remove a package of Daisy BBs as a cure … :wink:

If the shape is different, the valve may be the wrong one. It may open and close at a different (wrong) vacuum. I installed a wrong ported vacuum valve once and it did the exact opposite of what it should have. It made my heat riser valve close when the engine was hot.

I had two cars of the same year and noticed that they worked the opposite way. I went to the dealer to get the right one. A check valve won’t do the exact opposite but it can still be the wrong part.

Many EGR valves have delay valves in the vacuum circuits.

I found nothing on this part in any of my literature but Rod Knox is correct about the operation of a normal check valve.
That valve you show that was obtained from AutoZone is a generic check valve from the Self Help rack and is used on things such as heater/AC controls and so on. The AZ guy just assumed that what he gave you would be a suitable replacement.

You might drop by the Toyota dealer and have them look this part up. If it has not been obsoleted it could be that the price may not be as bad as you think.

It is an EGR Vacuum Delay Valve (or Spark Delay Valve) they are color coded to indicate the amount and direction of delay… Available online at RockAuto Parts or Advance Auto Parts