jerryb Posted November 9, 2008 Share Posted November 9, 2008 I just completed a turbo build on a stock KA24E. I had a heck of a time starting it up...wouldnt hold idle..... and tracked the problem down to the RB20/DSM style BOV. The BOV is vented to atmosphere and I discovered that if I cover up the vent/opening my RPMs go up and idles fine. In fact I can then reduce idle and it purrs. Im assuming the BOV is stuck open and drawing air. Is there anything I can due to the BOV to make it seal or is it trash and I just need to source a new "used" one? All comments appreciated....its an econo/cheapo build and Im doing my best to keep it that way! On that note.......Anyone have a spare kicking around ..if so please give me a shout. Thanx Quote Link to comment Share on other sites More sharing options...
linchpin360 Posted November 9, 2008 Share Posted November 9, 2008 If it is an RB20/DSM type BOV, take it of the car and crush the top of it to increase tension. If it still leaks go find another. Steve. Quote Link to comment Share on other sites More sharing options...
ktm Posted November 9, 2008 Share Posted November 9, 2008 Are you using an aftermarket engine management system? If not, is the stock ECU MAP-based? If the stock system is not MAP based, an atmospheric BOV that opens at idle can cause problems. It is essentially a large vacuum leak. Quote Link to comment Share on other sites More sharing options...
jerryb Posted November 9, 2008 Author Share Posted November 9, 2008 Stock ECU....No worries I understand. Its a lapping car that will be running full out when on the track...Im not concerned. I run my RB20DET the same way. Mind you with a Power FC and MAF...not MAP. It runs like a dream on the street. As far as the RB BOV....I did crush the top and it did tighten the spring but that didnt help. I was about to give it one more whack when I thought Id try to blow into the vacuum nipple to see what would happen. I heard an air hiss, so I flipped it around to see where it was comming from and found a small hole..... 1/16" or less.....right beside the large one. Obviously the RB BOV is not designed to run atmospheric and has the small hole for balance or something?? Bottom line its a non stop leak when connected to run open. I put a small piece of electrical tape over this hole, bolted it up and started up the car...it idles perfectly. I will TIG weld this hole shut and start working on the next problem. FYI...I removed every single emission device from the KA....attached a Z31 turbo on a log manifold.... hot piped it to the intake ...with a stock ECU......and so far the only issue(s) was a dead battery and this BOV deal. And they said it couldnt be done....mind you it hasnt run under load yet. Thanx for your replies! Are you using an aftermarket engine management system? If not, is the stock ECU MAP-based?quote] Quote Link to comment Share on other sites More sharing options...
blairjj Posted November 9, 2008 Share Posted November 9, 2008 Jerry, Since you've already crushed the BOV, this might be a mute point, but I still like to share this little trick: http://www.thedodgegarage.com/turbo_bov_mod.html Jay Quote Link to comment Share on other sites More sharing options...
jerryb Posted November 10, 2008 Author Share Posted November 10, 2008 Thanks Jay Very helpful tip...cut copied and saved in my archives for future consideration. Jerry, Since you've already crushed the BOV, this might be a mute point, but I still like to share this little trick: http://www.thedodgegarage.com/turbo_bov_mod.html Jay Quote Link to comment Share on other sites More sharing options...
jerryb Posted November 14, 2008 Author Share Posted November 14, 2008 I tried everything and couldnt get the DSM BOV to work on the KA. So I dug around in my spare parts and found an old jetson looking ARC unit. Installed it and it idles perfect now. Thanx! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.