I have had my kit for almost one year now. I have had no problems up until lately. I discovered that I ripped one of the silicone couplers for the Greddy FMIC. There was amost a 1 inch slit in it. I replaced the coupler and now I am having what seams like uncontrollable boost. The old duty cycle that is in my AVC-r isn't even close. The previous Duty cycle was 44. I am noticing that when I turn it off completely it rises quickly to .75 then starts creeping higher, Highest seen is .85.

This is the HKS wastegate that comes with the XS kit.

Anyone got any ideas

Thanks
Chris

 

Your best bet is to disconnect the BC (not just turn it off) and run straight off the WG (run a your line straight to the side port of your WG)

If you are still overboosting, then you know its an issue with the gate.

 

I removed the BC from the system. I am getting the same results. Interestingly enough I did a slow pull in 4th up to 6k and it controlled at .74 the while way. I could also hear the gate open. I tried it again in 3rd going down an on ramp. 6.8k, .87psi. Is it possible the gate could be sticking? I don't imaging the spring going bad and if it did it would open early.

This is just weird.

Chris

 

Make sure your boost line from the engine to the wastegate has NO holes or cracks. Don't just "look"... you need to remove it and inspect it.

Another idea... on my HKS Racing WG, the thing leaks internally where the wastegate "valve stem" goes through the base. You might want to try using an air compressor regulated to around 20 PSI (so you don't blow up your wastegate rubber parts or something) and see if it will hold 15-20 PSI without leaking from anywhere. That's how I found out mine leaks around the valve stem. Anyhow... just an idea.

 

Check your wastegate. Often times the bolt that connects the valve stem often works itself loose causing the wastegate to not open up fully...this has happened to my apex'i wastegate as well as two of my friends who have had HKS racing wastegates as well. The solution is often to just weld the bolt to the valvestem so it doesn't work its way loose anymore, but if thats' not an option just open up the wastegate and make sure everything in there is still in place

 

I replaced the vacuum line and it is doing a little better but now I am noticing that my fuel pressure is dropping after I get about 5psi. The AFR is increasing to like 14 very quickly after about 5psi at about 4K in 2nd rear. Could this be the fuel filter? Clogged? Down low I have lots of power but it begins breaking up under boost. I then realized my Fuel pressure was dropping.

Bad day for my 7.

Chris

 

TiteFD,

I will need alittle more explanation as to what bolt you are talking about. Interior/exterior - side hot/exhaust, etc. Thanks

 

If you open up your wastegate, there is a bolt that connects the valve stem that guides it into the valve guide. It is just a little nut that is screwed on, but oftentimes through excess friction and a lot of use, it tends to work itself loose given time. The nut is inside the wastegate, so you would have to open up the wastegate itself and inspect if thta nut is causing it to stick shut. As I said before this has happened to two of my friends who have had HKS racing wastegates and this also happened to my apex'i wastegate as well. Hope this helps, good luck diagnosing your car