Help! Engine will not stay running oddity!

[ESGWheel]

2017 CX5 Grand Touring AWD with ~ 80k, always serviced by Mazda at correct intervals.

It’s a daily commute car and one morning it would crank over (strongly) start running but stumble and die. So far validated fuel pump and its internal to the tank filter all ok and plenty of pressure as indicated by releasing the line to the pump (post key on) and getting lots of pressure released (not measured). Confident that is ok. Was odd in that it seemed like was rich so pulled the plugs and each and every one black as in too rich runing for some time. Smelled of gas when pulling the plugs as well (this was several days since list tying to start). Replaced plugs and similar but better in that it ran a little longer like 30 seconds before dying. Suspecting perhaps a failed open (or partially open) Evap Purge Valve I removed the hose from it to the intake plenum and plugged it. Now it will start and stay running for about 45 seconds and sounds all good then there is a loud clicking in engine bay and stalls. No codes so far.

Ideas?!

 

[N7turbo]

Wouldn't hurt to look at the throttle body.

 

[Silly Wabbit]

+1 on throttle body. If you give it a but of gas, would it stay on?

 

[ceric]

As ^ suggested... if giving it some gas makes engine keep running, but idle does not hold on by itself, you might have a ICV leak. (idle control valve)
Saw my co-worker's Lexus RX failed that way (15 yrs ago) when going home from office.

 

[ESGWheel]

It will not stay running regardless of throttle position. One of the reasons I went after the Purge Value was thinking it was stalling due to a vacuum leak and in my mind, I tied in the rich running (black plugs) to a leaking purge value allowing excess gas vapors. While I would have first suspected an IAC, I cannot find one. Said differently, I understand these engines do not have a IAC.

Do these 2.5 L skyactive engines have an IAC?

Thanks all!

 

[ESGWheel]

I have been eliminating any vacuum lines off the intake plenum. The Eap Canister via the Purge Valve and now what looks to be the vacuum hose for the brake booter > but this hose goes to a motor mounted device first and then the brake booster. This device is sticking off the cam cover. See picture. What the heck is it?

Note that with this hose disconnected and intake plenum plugged it started and ran for the longest it ever has (about 60 seconds) and responded to throttle but then died like a value opened creating a massive a vacuum leak (vs. fuel cutoff).

Also clear to me that I need an engine manual to continue. Any suggestions out there?

 

[GrampaSlade]

I think you need a proper scan tool and a manual.

 

[HyFlyer]

Do a search for manuals, there's been a few downloads floating around for years

 

[sm1ke]

This is a pretty good resource, but it's for the 1st gen CX-5. A lot of the engine related info should be very similar, if not the same.

Mazda CX-5 owners & service manuals, user guides

www.mcx5.org