'97 F355 spider 5.2 capristo bypass valve vacuum line question

Hopefully I'm understanding your question. But I disregarded the instructions and ran a shorter silicone hose off the factory alloy pipe like the oem one did. I didn't want a long hose when it made sense to just route it as per factory. I can assure you my bypass is working sensationally.

 

Also the silicone hose provided is fine so far. I'd be surprised Capristo didn't supply something adequate for the job.

 

I personally bypassed the factory metal tube and used the supplied hose. I was told the metal factory tube can develops cracks/leaks and the rubber hose is more reliable.

 

Sorry to hear your troubles. The solenoid supplied from Capristo is reversed from OEM. You may already know that. It closes when you start the car, the. Opens once the ecu tells it to. When I first got my car, the dealer had swapped mufflers before shipping. The Bypass wasn't opening because the connections on either side of the Bypass were overtightened and this was jamming the opening function. Loosened things up and it started working again.

Could be a vacume leak ?
Run the hose straight to the bypass valve. Not through the metal tube. See if it's any different.

That's all I got....

 

I'd have to go look. Can't remember. Just glad my problems came to an end !!

 

If the action is working at all, it's not overtightened as you found out. The fact that it closes on start up as it should means you are getting vacuum. My problem was that the system was working, but throwing a P1448 code. Goths Bypass TCU fixed that. Capristo told me that you can't run their Bypass with test pipes without getting a 1448, FYI.

I would call Capristo and have them send you another solenoid to try. They were very helpful to me. They will give you the correct vacuum pressure specs too.

How do you know it's not opening ? Just sound, or did you put a piece of tape on the action to see it ripped ?

 

Sounds good. Good luck.

 

Mine closes as well once the car warms up and the secondary air kicks out for a while then vacume builds and the two valves close.

Some how you are still maintaining vacume when the solenoid is open. Not sure why.

Did you tee in the vacume to the correct side of the existing valves?

 

So if plumbing is correct your solnoid is not opening to atmosphere. Is the solenoid getting power correctly. If you have it wired backwards it also will just remain closed.

As you said if that is correct it could be the extra thermocouple on the exhaust bypass I think. I think it also is used to open the bypass. At least thats what it says in the WSM.

Thats all I got except you could exchange thermose with either right bank or left bank and plug in to check..

If you do this the bypass might work but you will throw a false sld on that side.

I dont think the last thing is correct about the thermos but I am not possitive exactly how it works for bypass. It might just be a safety to open so as to lower cat temps but it does not specifically explain it.


It wont hurt anything and is easy to try which is why I suggested it.

Maybe bob can chime in he understands that system well for the sdl setup.

 

Rule out the entire thermocouple system. Call Ricambi and get Goths Bypass TCU box.

I personally don't think the thermocouple controls the opening and closing of the bypass valve.

 

They don't. The bypass valve is controlled by the engine ECU based on gear selection, throttle position and engine RPM.

 

Correct.

The BP TC tells the ECU if the BP valve has opened or not based on the temps it detects. In my car I have the output of the BP SDECU tapped and in observing it real time under driving conditions the output voltage is around .8v in the closed position , warmed up and gets up to 1.4v when getting on it throttle wise when the valve opens.

I don't think the ECU does anything with this information but throw a CEL for the BP valve operation.

AS Skipp can attest with his straight pipe and Tubi header set up, and upstream change in the exhaust system can alter the temps detected at the BP TC and throw CELs. Using a fixed voltage ecu like Goths will defeat the BP SDECU function with no apparent detriment.

 

Unfortunately with Skipp's situation, we actually don't know the root cause of the problem. He elected to forgo further diagnostics and use Goth's hardware as his frustration was building. I don't blame him but I'd still like to know the root cause and issue without speculation.

 

To add more info, I was told by Capristo's tech that they're bypass valve can not be used with test pipes without throwing a 1448 CEL. Something to do with exhaust flow and temperatures. So, I do believe I got to the bottom of the issue. Goths box simply made it possible to run the Capristo bypass with test pipes. There was nothing wrong with the components of my car per Capristo, just the way it is with this combination of exhaust parts.

 

Thanks, Skipp. That's interesting. My guess would be too low of temperature given the free flow of test pipes. I still wonder if this would be an issue with the OEM bypass valve (Tubi headers, and test pipes) ???