Dump valve issues

sp7_oks · December 03, 2009, 03:26:39 PM

Hey everyone, so I managed to get my car mot\'d it\'s been running pretty good for the last 2ish weeks ignoring a few fanbelt issues. I fancied a bit of pACHISSSH action so I bought a relatively cheap dump valve off ebay it\'s a single piston fast road forge dumpvalve, it seems like pretty good quality. Anyways I slapped that on, replacing the recirculating valve thing that was already there, I plugged up the hole that it left going into the airbox, and connected the vacuum pipe that came off of that to the dump valve.

After this the car ran pretty poorly, rubbish idle, backfiring when coming off the loud pedal, still boosting pretty well though and making a nice pACHISH sound, so I figure I messed something up putting it on, or got the wrong kind of dump valve, I think I read somewhere on here that you need a twin piston dump valve to make it idle properly?

It seems to me like the dump valve is leaking air on tick over messing up the air flow and causing over fueling and the bad idle. Any help would be appreciated

Prof · December 03, 2009, 03:38:43 PM

Yep - Bailey\'s double piston on mine.

grinder · December 03, 2009, 04:40:54 PM

i have ran blitz ones on both my cars and had no issues with either of them

the hat · December 03, 2009, 04:57:17 PM

the problem is the vacum on idle causes the valve to open im sure i would have a spare dumpvalve kicking around that will work a treat if you want one

sp7_oks · December 03, 2009, 05:21:18 PM

Yeah I thought that\'s what was happening, I was hoping I had just put it on wrong, if you have a spare one lying around that would be awesome!, would it be just for postage costs :cheers

monterx7 · December 04, 2009, 02:49:23 AM

can you adjust this dump valve?

i use to run the apexi bov and it had an adjustment screw just incase it would like at idle. if it did, you just tighten the screw thing. i believe greddy has a bov with the same adjustment on top

sp7_oks · December 04, 2009, 09:29:40 AM

It\'s a sealed unit, can\'t change anything on it

rx7pat · December 06, 2009, 06:06:09 AM

It could be the dump valve is leaking in the vacuum pipe. I had it once before, if you pull the vacuum pipe (the small one) off of the dump valve and block it, then see if the idle returns to normal. When mine done that I bought a turbo smart one which is Awesome!