CEL Fuel Pressure Solenoid

[Scrmegl]

'98 Talon TSI AWD
K&N, MBC, 1G BOV, UICP, Fuel Pump Rewire, 3" exhaust.
I have had my check engine light come on and set a trouble and hard code. I stopped by Checker to have them scan it and it came up as Fuel Pressure Solenoid. I believe this is a P1105 but I forgot to verify that.

I did a basic check of the vacuum hoses and electrical connectors and they seem fine. I found a ground strap under the car not connected and since attached that.

The searches I have done turn up mixed and sparse information of how to properly diagnose this. The code is recurring after clearing the code and also after an ECU reset (disconnecting battery for a while). Am I on the right track with checking the Fuel Pressure Solenoid itself or would there be a chain reaction place to check as well?

The car seems to be running fine and hasn't been acting up or idling/starting hard. Any thoughts appreciated. Thanks.

[Halon]

I'd say try swapping it out with a known good one and see if the symptoms remain.

[Matt D.]

As far as I know the fuel pressure solenoid only does anything on startup, preventing vacuum from reaching the fuel pressure regulator until the engine is running.

[asshanson]

I was under the same impression, if it's removed it may take a bit longer to start sometimes. I took mine out and had absolutely no problems, I just disconnected the solenoid and hooked the fuel pressure regulator up to the intake manifold directly.

Do you have link? You can disable all those emissions CELs if you do.

[Scrmegl]

I only have an AFC Neo for tuning.

Hmm This statement below seems counter intuitive. For cold start you would want higher vac/ thus higher fuel pressure, correct? And Hot you would want it blocked to go to lowest base pressure?

I did find this: http://members.shaw.ca/dsm.1000q/Eng.../solenoids.htm

"The right-most solenoid, marked with a green arrow, is the fuel pressure solenoid. This solenoid allows the engine control computer to temporarily raise the fuel pressure for hot starting purposes. This is accomplished by cutting off the vacuum hose going to the fuel pressure regulator. It is not used for anything else, but it can provide a useful tap-in point for a boost gauge, since the regulator "sees" the intake manifold pressure. (If you tapped your boost gauge in here, but it doesn't read any vacuum right after warm or hot starts, you probably connected to the wrong side of the solenoid.) "

[asshanson]

Hmm I can't remember if it helps hot or cold starts, either way I haven't noticed at all. I think I have my old one still if you want to test it out.