Join Date: Dec 1999
Location: CA, USA
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Vacuum spec at Port R on Throttle Body?
Long time, no visit. I have an upcoming smog check (22RE engine), and since I just barely passed my NOx test two years ago, I'm nervous about passing it this year. Based on those tests, and my somewhat lackluster engine performance lately, I think I may have some EGR operational issues. I went through the checks in the FSM, and that all checks out fine. However, I decided to check the vacuum for the "R Port" and "E Port" on the throttle body (since those control the EGR function), and got some strange results. The FSM says I should be able feel vacuum on these ports at 3000 rpm, and no vacuum at idle. I decided to get more scientific about it, and hooked up my vacuum gauge to the ports instead. On the E Port, I get strong vacuum around 3000 rpm. Like around 15 mm Hg as I recall. On the R port, I get barely anything (4 mm Hg or even 0). Thinking the R port was plugged with carbon, I sprayed throttle body cleaner down the port, and also blasted it with compressed air. On top of that, I poked a thin wire all the way through it, and moved it back and forth. Seemed like it was clean to me, but when I checked it with the vacuum gauge, it didn't seem any better. I can't figure out why it so low, when the E (and also P) port seem so strong. Anyone have any suggestions? Could it still be plugged up after all that, or is it supposed to be that low. One thing I did notice is that the vacuum at the R port jumps during the process of twisting the throttle, but won't stay steadily high like the other two. Also kind weird.
87 4Runner, 2.4L, 22RE, EFI