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88 Dodge Shelby Lancer 2.2L T2 with moderate upgrades

Ok so I don't know where to go from here , i feel like im missing somthing simple or I'm going NUTS!!!
Code 13 map sensor fault
started coming on now and then . Mostly was a hidden code ( check engine light was not on, but would come on for a min or two now and then)
Started to get worse ( check engine light would turn on shortly after start up, and surging once and a while, while driving)

Ok so I replaced the map sensor , fuel pressure regulator , new pigtail for the connector into the map sensor. Got a shop to pressure and smoke test my vaccum . No leaks!( not all at once , sensor first then pigtail, then vaccume testing, then fuel pressure reg)

( I generally replace and repair old parts before they need anything)

I don't know where to go from here . The surging is driving me nuts . I have my timing set to +16 but I don't think that's doing anything to cause the issue, just thought I would mention it just incase
 

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Other than the Vapor Canister System not really a lot.
(Do not know anything about emissions tampering/vehicle inspection in Canada)
You need Manifold Vacuum to the...
1)Baro Solenoid (From Solenoid to Map Sensor)
2)Fuel Pressure Regulator
3)Wastegate Solenoid (From Solenoid To Wastegate)
4)Boost Gauge

You need the PCV System connected.

And of course on the other side you need...
1)Brake Booster
2)HVAC
3)BOV (if equipped)
You can delete the Cruise Control if equipped.

If I may make a suggestion...
Get the Code 13 sorted out before tearing apart the entire vacuum system in case other issues arise when doing so.

You will need to install a vacuum block unless it has already been done.
INSTALLING VACUUM BLOCKS
https://www.turbododge.com/forums/f4/f14/363281-installing-vacuum-blocks-84-93-t.html
 

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If you have any issues/questions please feel free to ask.
I have a question...
I have a code 13.
If I hook the vacuum line directly to the map sensor it goes away.
If I run the vacuum line through the (baro?) sensor/solenoid underneath the map sensor it comes back immediately.

If I unplug the solenoid, it goes away.

I thought I had a bad solenoid but found out it was working properly.

It seems that whenever the ignition is on, 12v is sent to the solenoid, it activates the solenoid and opens the vacuum line leading to the map sensor, to atmosphere.

I'm now assuming that the map sensor is not reading a change in vacuum or pressure because the solenoid is constantly open and any change in pressure is just vented out the back.

Am I missing something?

Also the vehicle does not like to idle steady and surges ever so slightly. Almost as if there is a vacuum leak which I would assume is the solenoid being open constantly to atmosphere.
There are not any other vacuum leaks.

I have not tried it but I would assume if I put a vacuum cap on the vent at the back side of the solenoid, that would compensate for the issue but I don't think that's fixing the actual issue. Is that solenoid supposed to be open to atmosphere? Is it supposed to be closed? And if so when is it supposed to open and close?
 

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Test the Solenoid and Wiring,.
With the key on there will always be 12 volts to the Solenoid, the SMEC controls the ground side of the solenoid which opens/closes the passages.
DB wire is a constant 12 volts from the ignition switch
LB is ground side control from SMEC cavity 38.
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Test the Solenoid and Wiring,.
Welp, everything checks out. Solenoid opens and closes when voltage is applied, no breaks in wires. Good voltage. Problem persists if i swap the computer.
But every time I connect the vacuum line to the solenoid and then to the map sensor I get a code 13.
If I remove the vacuum line from the solenoid and connect it directly to the map sensor, the code goes away.
Vacuum source is a manifold connected directly to the intake.
Checked the vacuum lines for any blocks or restrictions, and everything flows properly

I'm really lost here.

Also to point out it is a new three-bar sensor, aftermarket from advance though. (Old one did the same thing)
Fwd performance S5 ecu.
 

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1)Is engine vacuum reading the same before and after the solenoid?
2)Are the vacuum lines connected to the correct ports on the solenoid?
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3)What is MAP voltage reading with the KOEO (Key On/Engine Off)?
4)What is MAP voltage reading at idle when you start the car?
a)With the Baro solenoid in the circuit?
b)With the Baro solenoid bypassed?
5)Is MAP voltage reading the same as in step 3 after you turn the engine off?
Rectangle Parallel Font Number Pattern
 
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