First, I thank andykrow for posting his issue and question here because without reading about these of issues, many people may struggle with lots of frustration, time and money to find a fix.
I especially thank “Dr. emsvitil” for his time and generosity to continuously share his knowledge and experience here to help us diagnose and figure out the answers to these common questions on the 22RE. In my experience or inexperience, and reading so many posts about the 22RE, its very obvious that this engine is WAY more complex with its ECU-controlled design, than the 22R, and requires lots knowledge on the components that control the AF and other functions.
snowtoy, although he disappears for awhile, has also made many contributions to help diagnose and provide great information...Thank you!
There are obviously others who post great stuff, and you know who you are... thank you.
As I try to follow and educate myself from the posts, I would like to make sure I understand what was going on and how the changes and testing was done to uncover the problem with the EGR valve.
So do I have this right?
The EGR valves needs to have a certain flow from a partial amount of exhaust coming from the head via the exhaust manifold.
The Rimflex gasket used by andykrow was causing a partial blockage of flow.
The LCE header, as described by the comments on Roger’s site in the link that was posted. From the small notch that he describes that is on his LCE header…
Quote: “On the LC header, there are little notches milled into the header flange to send gas to those two ports. But I found two problems with that design that caused flow restrictions due to the small depth of those passages. One was that the header tube weld bead protruded into that milled notch. So I took the time to grind down that weld bead and even round over the inside edge to aide gas flow into that EGR port. The second issue was the thin web of gasket material between the main exhaust port and the EGR port. Over time, carbon builds up on that gasket and makes it thicken and intrude into the gas passage. So I simply took a new gasket and cut out the web of material between the main and EGR port, shown in red below. The basic idea is to make the #2 and #3 ports have a larger opening. In the stock cast iron exhaust manifold, there is a dedicated gas passage cast into the manifold that takes gas from the exhaust runner back to the EGR port hole. But the way the LC header is set up, they rely on that small passage into the flange and thus there is no need for a gasket in between the two holes, as there is no contact between the flange and head at that point.” Unquote.
As many of us know Roger’s contributions to the early Toyota trucks and 4Runners owners over many years has been incredible!
From Roger’s post, I am surprised that LCE failed to properly design its highly touted header to correctly supply the necessary exhaust flow to the ports for the EGR. Perhaps they have corrected that apparent design flaw. That is one of reasons I have stated before when discussing aftermarket suppliers, that just because an “expert” says it or makes, doesn’t mean its right – there are many many examples of this.
It’s nice to know that the Doug Thorley header appears to be correctly designed for the exhaust flow to the EGR system.
I will also test my EGR valve see if it’s working properly. Right now I’m running the stock exhaust manifold and exhaust manifold gasket supplied by the engbldr kit.
andykrow…I commend you for your tenacity to find the problem, while sharing your experience here. I hope you have fixed your engine so it will pass your state emissions test and get back to enjoying your new rebuild.
I am also hopeful that the 261C cam is NOT the problem and causing a lean mixture?
I apologize for my wordy posts.
Gnarls.
