Piston Dump Valve.....All I get is chatter
Turbo Mini Forums

strip and clean it, check the o rings for swelling and whack it back together with a smear of vaseline

i think it is supposed to be open at idle.

Yeah,

It seems to dump but only after the chatter which makes me think its sticking.

At idle, the main piston slides open and the small nylon one stays shut. Rev it up and it all opens up.

WOndering if its maybe loosening up.

Il try some vaseline on it tommorro and see how that goes.

yeah mine did the same... i used wd40... (dont use wd40 lol) but it worked! just get something lubricative on it! and it should definately work

Cool,

Do you reckon the fact that the turbo chatters then the dump valve comes in late is just due to it sticking?

Yes i moved to the darkside

Instagram @jdm_brett

Lol, cool. Il try lubing it up then.

I think the twin piston ones are supposed to be for injection cars so one piston stays closed at idle to avoid messing up the air metering.

one of the pistons cold be stuck shut, what vac pipe are you using? check it is not collapsing.

Im just using silicone vac pipe....

Just stuck a brand new diaphram dump valve on. Didnt make any difference. Still chatters.

Any ideas?

Silly question but you did you take the blanking screw out of the manifold take off?

Yeah, the srews removed. I did have to go check tho.lol

Edited by hammoj28turbo on 28th May, 2010.

Heres my setup. Im stumped.lol

Just a thought,

At idle with the piston dump valve, My boost gauge rev on the - scale.

With the new duaphragm dump valve which is closed at idle my boost gauge is sitting at 0. Like its not getting a reading....wonder if that port is blocked somehow....

Should there be resistance when you blow through the vacuum take off spacer?

I cnt poke anything down it? But if I blow through it I have to really blow hard.

Is it a straight through pipe or does it branch off?

Had a look at the vacuum spacer and there is a hole in it but its tiny. Is that maybe my problem?

I dont even get a reading on my boost gauge now with this new dump valve on.

if the hole is tiny then YES, if the holes in that T piece are small then yes it wont work... i have a t piece on mine but the t piece has 2 large holes and 1 small (the small one is sent to the gauge and the other 2 to the manifold and the Dump Valve... make sure the hole in that spacer is at least 3mm? take it off and drill it

Hmmm, the whole in the take off is hardly 1mm id say.

Also, the dump valve is faulty. You can blow into the top of the vacuum bit on it and it comes out so its not sealing. Waiting on a replacement.

Got the piston dump valve working!!!!

Turn out the hole in the spacer plate was too small.

I took the brass fitting out and drilled it through so it was straight through.

Slapped it all back on and Ptshhhhh. No chatter anymore. Hehe, awesome.

Good work! Top marks for posting good quality pics rather than the blurry ones people tend to post too!

nice!