IAC Check Valve on '01 - '02 4Runner
05-01-2003, 12:40 PM
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IAC Check Valve on '01 - '02 4Runner
This subject is being discussed under another topic --- "Flooring with the SC", but I thought this information is too important and might be overlooked by some who really need to know.
Nick "BlueTrane", through dogged tenacity, and with the support of Fowler Toyota in TX has come to a resolve for some of the problems those who own '01 and '02 4Runners are having.
The TRD installation manual instructs that we are NOT to install the one-way valve in the IAC vacuum line on the throttle body. TRD has just revised their directive saying that the valve should be installed. One of the conditions created by not having the IAC check valve in-line is the surging and hesitation that Chris was experiencing. I believe that the IAC line is drawing upon boost air and is therefore creating all kinds of problems (i.e. lean condition) for the Idle Air Control. I do not understand fully what is happening but after I just installed the valve and drove the truck, I was impressed at how the truck ran at WOT. I am also using the stock BKR5EKB-11 NGK plugs gapped at .032 instead of what they are suppose to come gapped at (.042).
The TRD PN is 00602-17620-065. Go to "Flooring with the SC" to see a picture of the valve if you need to (It's an attachment on page 2 or 3)
The black mark is to be facing toward the throttle body because this is a one-way valve.
Besides the check valve, the other areas to look at are:
The FPR is to be connected to the brass boost port to facilitate FMU operation.
The small port on the back right side of the throttle body should be capped.
I am very pleased with this latest finding and hopeful that it will help a lot of us suffering pre-ignition, erratic performance and drivability.
Try the install and post your findings.
Nick "BlueTrane", through dogged tenacity, and with the support of Fowler Toyota in TX has come to a resolve for some of the problems those who own '01 and '02 4Runners are having.
The TRD installation manual instructs that we are NOT to install the one-way valve in the IAC vacuum line on the throttle body. TRD has just revised their directive saying that the valve should be installed. One of the conditions created by not having the IAC check valve in-line is the surging and hesitation that Chris was experiencing. I believe that the IAC line is drawing upon boost air and is therefore creating all kinds of problems (i.e. lean condition) for the Idle Air Control. I do not understand fully what is happening but after I just installed the valve and drove the truck, I was impressed at how the truck ran at WOT. I am also using the stock BKR5EKB-11 NGK plugs gapped at .032 instead of what they are suppose to come gapped at (.042).
The TRD PN is 00602-17620-065. Go to "Flooring with the SC" to see a picture of the valve if you need to (It's an attachment on page 2 or 3)
The black mark is to be facing toward the throttle body because this is a one-way valve.
Besides the check valve, the other areas to look at are:
The FPR is to be connected to the brass boost port to facilitate FMU operation.
The small port on the back right side of the throttle body should be capped.
I am very pleased with this latest finding and hopeful that it will help a lot of us suffering pre-ignition, erratic performance and drivability.
Try the install and post your findings.
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