Today I was heading back home and the Cobra would not make any boost. When I first drove it today it didn't have any problems. Throttle position doesn't matter the boost gauge will go up to 0 and stay there (aftermarket boost gauge), and the rpms will continue to rise as long as I stay in it. I don't hear any blower whine when giving it more throttle. What parameters would be recommended to datalog to see what the issue is? I'm assuming Fuel Pressure, Misfires, MAF Counts but I'm sure I'm missing something.
What parameters for datalogging no boost condition?
- Thread starter BMOC
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If you don't hear the supercharger spinning, it's not.
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Was the battery light on? Either you lost the belt or the bypass is stuck open.
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You can't delete the BPV. It's part of the blower. And it's a necessary part of the blower living longer.
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Then I have no idea where it's located. I thought it was on the driver's side but when I looked I couldn't find it. So I finally got a scan tool on it. It has a code P0172 Fuel System Too Rich Bank 1 and P0148 Fuel Delivery Error. I looked at the fuel pump duty cylce on the scan tool and at idle it bounces from 87% to 114%. If I blip the throttle it immediately pegs at 100%.
Edit: Nevermind I found it. It's on the back side of the blower. I'll hook a vacuum hose up to the bypass valve and see it if works.
Edit: Nevermind I found it. It's on the back side of the blower. I'll hook a vacuum hose up to the bypass valve and see it if works.
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Yes. It opens when there's a vacuum and closes when there is none, IE boost. Have you tried driving the car again?
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Datalogging won't help you. This should be a mechanical problem.
Rich code is likely only there due to there being no boost.
Rich code is likely only there due to there being no boost.
Yeah I understand the functionality. What I thought was weird was the bypass valve is mounted horizontally where the shaft would move from the front to the rear of the car when opening and closing. When I rev the engine the shaft will move up and down (from the ground to the sky vertically). I can drive the car. But it doesn't build boost at all.
I'm going to take the belt off Monday and spin the blower by hand and see how it feels. But the fuel pump duty cycle seems like an important factor also.
I've seen high FPDC when having voltage issues as well as FRPS issues. I wonder if the FRPS is acting up and causing the ECU to shut off the BPV? Is it possible for the ECU to do that?
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Are you sure the bypass is closing when you step on it? You can try tying it closed and going for a spin to see if you make boost.
The rich code sounds like a possible vacuum leak. Have you checked all the vacuum lines?
I guess a blown FRPS could affect the bypass actuator causing all your issues. Check for fuel in your vacuum lines.
The rich code sounds like a possible vacuum leak. Have you checked all the vacuum lines?
I guess a blown FRPS could affect the bypass actuator causing all your issues. Check for fuel in your vacuum lines.
I did check the vacuum line at the FRPS for fuel and it was dry. I'll try it again tomorrow to make sure. I've checked all the vacuum lines and I can't find any leaks, but I'll spray the lines with some brake clean and see I can find anything that way. I'll have to try tying the bypass valve to see if that changes anything.
Brandon,
The good news is that these cars are rather simple from a controls and operation standpoint. The downfall is that the diagnostics cannot always point us to which systems or parts need attention. Personally, I would try replacing the FRPS first. Worst case, you end up with a spare (which you should have already). The FRPS is primarily used for injector compensations. Depending on how you routed your lines, the FRPS may share a manifold reference with some other systems. In my opinion, I would consider the FRPS and boost bypass actuator separate systems.
If you can rule out the FRPS, I would definitely suspect an intake leak.
Don't forget to check the vent hose located on the under-side of the lower intake. People sometimes forget that there is a hose down there.
Good luck!
The good news is that these cars are rather simple from a controls and operation standpoint. The downfall is that the diagnostics cannot always point us to which systems or parts need attention. Personally, I would try replacing the FRPS first. Worst case, you end up with a spare (which you should have already). The FRPS is primarily used for injector compensations. Depending on how you routed your lines, the FRPS may share a manifold reference with some other systems. In my opinion, I would consider the FRPS and boost bypass actuator separate systems.
If you can rule out the FRPS, I would definitely suspect an intake leak.
Don't forget to check the vent hose located on the under-side of the lower intake. People sometimes forget that there is a hose down there.
Good luck!
I followed the vacuum lines from the FRPS and the bypass actuator and they are on the same vacuum system, just some t-fittings in between. I sprayed the lines down this morning and didn't find anything, even on the lines on the elbow after the throttle body. I found out that the o-ring for the MAF sensor was in three pieces so I'm getting a new one. I'll also get the FRPS for the hell of it and see what happens. I took the belt off the blower this morning and it had some resistance like it should it didn't spin too easily or too hard so I don't believe the blower is the issue.
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So I hooked the smoke machine for evap systems to the vacuum system and I found the leak. I'm not too sure what it is. But it's a plug that's threaded or pressed into the base that the bypass valve is connected to. It's underneath the elbow of the blower on the backside.
Edit: It's part of the shaft that the bypass valve is attached to. It rotates with the shaft when I move the bypass valve in and out. I assume it shouldn't leak air out of that?
Edit: It's part of the shaft that the bypass valve is attached to. It rotates with the shaft when I move the bypass valve in and out. I assume it shouldn't leak air out of that?
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