I picked up a used type H34 recirc valve used from a guy off here. The valve is in great shape, but I'm having issues getting it to work right on my Evo. My first try was the stock spring with 2 washers, and it acted just like a VTA setup...as soon as I would come to a stop, my afr's would drop into the low 10's and the car would stall. Ok, figured the spring was too loose, so I added more spacers to it. Now today all I heard was compressor chatter all day long, unless I was at 20psi. What gives? I tested the stock bypass valve at idle to see if it stayed open, and what do you know...it stays shut at idle, unlike the turbo xs unit. I'm going to try installing the h34 valve in reverse to see if it will stay shut, but if that doesn't work is there a certain amount of spacers I have to use to get this working properly?

 

Ok, reversing it just made the surge worse. Looks like I'm back to the stocker for now until I can get some better answers.

 

you just nee to find a good medium with the washers fiddle with it until it stays closed but opens when it needs to.. i would try 3 washers & go from there, lube the slide on the valve with some grease so it moves freely.

 

I have it lubed pretty well with some lithium grease, slides rather well, but I've tried everything from no shims to 8 shims and it still acts up. It's getting to be a huge PITA to have to pull the maf off my Injen intake every time I want to add a shim lol.