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You might check to see if you have vacuum at the fuel pressure regulator:
http://www.4crawler.com/4x4/CheapTricks/22RE_Engine_Pix/8.html

With no vacuum feedback, the fuel pressure can rise too high at low engine loads and cause the engine to run rich (high HC readings).

And yes, you could test the coolant temp sensor, if it is reading too cold, the ECU will try to get the engine to warm up by dumping in extra fuel.


Roger, thank you so much for this tip!!! I struggled with high HC since 2002. I have failed smog twice, and when I pass the HC's are close to the MAX 131ppm. With over 300,000 original miles on the engine, I figured it was just because the engine was old.

I checked, and my VSV was bad. I bypassed it like you did, and I just passed smog with flying colors. HC measured only 32ppm at both 15MPH and 25MPH!

So, thank you again. This is awesome! <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" /> <img src="/forums/images/graemlins/cheers.gif" alt="" />

Mike Carter
85 & 86 4Runners

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