The more I read, the less I know (Purge valves)

[Luckyman01]

At one point I thought that the valve under in intake manifold was THE purge valve. However I am reading references to one under the right front fender.

I do understand the valve attached to the gas tank tube, I think.

However there seems to be something on the upper wheel well that is referred to as a valve as well.

There seems to be valves associated with both the EVAP and SAI.

Can someone give me a clear narrative.

I am chasing a does not start?

David

[The Radium King]

sai injects air during start-up to improve emissions. the sai system consists of an air pump connected to an electrically-actuated pneumatic valve mounted on one head with a connector pipe to the other head.

there is also a charcoal canister located in the front right wheel well where evaporated fuel (evap) accumulates when the car sits. on start up this canister is purged to the intake via two valves - an electric valve located by the intake (the evap canister purge valve) and a second electric valve located on the charcoal canister. (the operating purge valve).

http://986forum.com/forums/performance-technical-chat/78104-could-yall-walk-me-through-evap-system.html

[Luckyman01]

I am strongly suspecting the purge valve 996-605-203-01, reviewing my receipts I find I bought one from Sunset Porsche online in 2018. $64.74 delivered to me.

Today they want $294.16 for one, big ouch.

My plan has to be remove mine and test it.

I am not sure what I am hoping for other than to get the car running.

Thanks again.

David

[Lowski]

This diagram explains the ORVR function of the EVAP system, but it also shows the rest of the EVAP system components. The valve at the intake failing open can cause the hard start after fueling condition.

What makes you think the EVAP system is the source of starting issue?

[Luckyman01]

What I know.

The car will not start, will crank.

The car will start and run when I jump the fuel pump relay, the relay tests good.

I have checked fuses.

I did have an overflow situation will fuel flowing over at the filler. Likely red herring?

I did look at the charcoal canister and it is dry.

So I am looking for a reason that the car (ECM) is not sending a signal to the fuel pump for some other reason.

So it seems to me that I likely have a misfunction in the vacuum system somewhere..

I currently suspect the purge valve under the manifold.

I did borrow a vacuum tester yesterday and will check that and look for other disconnected hoses.

The AOS is recent and does not seem bad.

This said I am not real confident at this point.

Any thoughts?

David

[The Radium King]

typically that stuff will throw a code? no ecm signal may be something else - ignition switch, cps, etc. - lots of other causes (and associated diagnostics) if you search 'boxster crank no start'.

Originally Posted by Luckyman01

What I know.

The car will not start, will crank.

The car will start and run when I jump the fuel pump relay, the relay tests good.

I have checked fuses.

I did have an overflow situation will fuel flowing over at the filler. Likely red herring?

I did look at the charcoal canister and it is dry.

So I am looking for a reason that the car (ECM) is not sending a signal to the fuel pump for some other reason.

So it seems to me that I likely have a misfunction in the vacuum system somewhere..

I currently suspect the purge valve under the manifold.

I did borrow a vacuum tester yesterday and will check that and look for other disconnected hoses.

The AOS is recent and does not seem bad.

This said I am not real confident at this point.

Any thoughts?

David

[Luckyman01]

The truth is that she did throw a code a couple of weeks ago. I have misplaced my note; ( I do go deer in the headlights sometimes) however it was a 400 series code and referenced a leak.

At the time I cleared it and waited to see. There was not a cel after that.

Today I pulled the purge valve from under the left side manifold and put some vacuum to it. , The valve does not hold air and does a slow bleed down.

Is this possibly it?

David

[JFP in PA]

Could be, but difficult to know without the codes