P1 Stalling

Thanks Simon. I will check .
Just can't work out why when I fitted majorscooby's standard one , it didn't seem to make a difference.
Is it possible a leak on the IC pipe work could cause the dump valve to do what it's doing.

Many thanks for super quick reply

[Jolly Green Monster]

Its possible yes.

If you wrap your fingers around the dump valve you can block it and you should be able to feel when it is open. Idle should improve when blocked even if not fully.

Did you fit the return to inlet pipe with the oe dump valve?

When I fitted the OE dump valve I removed the forge bung and refitted the pipe to the dump valve.

Right time to get outside and take a look
Watch this space

[Jolly Green Monster]

So in theory the oe one should have fixed it if it was the forge but it looks like it is to me the issue.

[Scott.T]

Zooming in on the video, I agree with Simon.
The DV almost seems to be working in reverse.

When at idle and when you open the throttle it should seal, when you come off the throttle it should open.
This will occur all the time there is a differential pressure/vacum between the engine side and the intercooler side i.e when on boost/driving and the throttle is open the pressure in the intercooler is the same as the pressure on the engine side therefore the DV is closed.
As soon as you close the throttle the pressure on the intercooler side remains due to the turbo still spinning and the pressure backing up against the closed throttle.
On the engine side as no turbo pressure can get through the closed thottle it goes into vacum.
Due to this pressure difference the dumpvalve opens, venting the excess pressure either back to the intake or to atmosphere (depending on valve).

The DV is mounted such that one side (where it bolts to the intercooler) is being moved by turbo pressure and the other side, the vacum hose uses engine pressure. All the time they are near equal in presssure there should be no movement of the DV.

The vacum hose should be connected to one of the 3 nipples on the middle of the intake manifold. make sure this is in the right place and has no weird hose joiners in it that could be on-way valves (thats the only thing I canthick of at the mo').

[Scott.T]

Have you tries running it without the dumpvalve.
knock up an ally plate and mount it to the DV mounting. i've got one kickingabout but quicker for you to knock something up rather then come get it.
You can use the DV to hold it in place. Then blank off the vacum hose normally conected to it.

[Jolly Green Monster]

Remove dv.

Compress piston with finger, block the vac pipe connection with another finger.
Release the piston, if the piston moves back to closed position the diaphram is fubar.

Forge dv are not good, their actuators are v good, dunno why.

Simon

Update guys
I have been over majorscoobs so thought I would try my dump valve on his, and it's perfectly ok.

Put it back on mine and out of curiosity pulled the small vacuum hose off and stuck my finger over it.
Problem solved , car runs perfect.
Dump valve obviously stays in one position .

Any ideas chaps

[Jolly Green Monster]

Have you checked the diaphram?

I still think its the forge dv

Will check it Simon.
Only reason I havnt is because it's perfect on Majors car

[Jolly Green Monster]

Different car though.

The forge ones fail regular.

Have you tried the dv off majors car on yours?

Hi Simon, yes tried majors standard DV and was no better.

How comes when I take vacuum pipe off the dump valve the car is spot on, is it because the dump valve then stays shut .

[Jolly Green Monster]

Yes.

If it had a stronger spring it would hold shut

[C. J.]

When I had a forge dump valve I rang them up and they sent me a free service kit with new spring for free .

Bloomin thing , I'm sure you guys are right. It's just thrown me because of majors standard didn't cure it , very odd

[Scott.T]

The forge doesn't have a diaphragm just a spring and an alluminium piston. as mentioned you can get different springs and shims. They used to list a full kit for about a tenner.

It doesn't explain why it does it with a standard valve though. Its as if you have too much vacum on the engine side when the throttle is closed compared to the levels on the intercooler side of the throttle.

Did u check all the intercooler pipes and connections and breathers.

[majorscooby]

Originally Posted by SilverSurfer

The forge doesn't have a diaphragm just a spring and an alluminium piston. as mentioned you can get different springs and shims. They used to list a full kit for about a tenner.

It doesn't explain why it does it with a standard valve though. Its as if you have too much vacum on the engine side when the throttle is closed compared to the levels on the intercooler side of the throttle.

Did u check all the intercooler pipes and connections and breathers.

We was going to do that yesterday but run out of time.

We did say the whole intercooler needs to be popped off and checked underneath as some of the larger pipes look like thay have been over tightened. pinching up somewhere?
The small vacum pipe that comes off the DV does look like hardend plastic and wiggles at the connection. i would personally replace it and i think mart will.

[Jolly Green Monster]

Originally Posted by SilverSurfer

The forge doesn't have a diaphragm just a spring and an alluminium piston. as mentioned you can get different springs and shims. They used to list a full kit for about a tenner.

It doesn't explain why it does it with a standard valve though. Its as if you have too much vacum on the engine side when the throttle is closed compared to the levels on the intercooler side of the throttle.

Did u check all the intercooler pipes and connections and breathers.

It doesnt have a rubber diaphram but it has to seal the vac line area with the piston.
Ie. work like a diaphram. If you compress the piston and place your finger over the vac connection the vacuum created should hole the piston in place. If it doesnt then air will be sucked through the vac pipe or escape through the dump valve depending if on boost or not.
And the piston will open when it shouldnt.