Surging Idle- 94 Cobra

What is causing the surge?

  • Vacuum Leak

    Votes: 2 66.7%
  • Idle Air Control

    Votes: 0 0.0%
  • MAF

    Votes: 0 0.0%
  • Tune

    Votes: 1 33.3%
  • Owner (me) did something stupid

    Votes: 0 0.0%
  • Something Else

    Votes: 0 0.0%

  • Total voters
    3

Michael Plummer

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What does "leaking down and washing the maf" mean?
Leaking down: Water/methanol fluid left in the nylon tubing is sucked out by the engine vacuum and this fluid flows or dribbles in the opposite direction of the engine/throttle plate.

Washing the MAF sensor: Under harder acceleration, the "leaked down fluid" gets picked up and is blown over the MAF sensor. Repeated cycles of this will eventually destroy the MAF sensor.

Fix: Install your Water/Methanol Injection nozzles behind your throttle plate and use a good solenoid close to your nozzles.

I hope that helps
Michael Plummer
 
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oilspill

oilspill

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Leaking down: Water/methanol fluid left in the nylon tubing is sucked out by the engine vacuum and this fluid flows or dribbles in the opposite direction of the engine/throttle plate.

Washing the MAF sensor: Under harder acceleration, the "leaked down fluid" gets picked up and is blown over the MAF sensor. Repeated cycles of this will eventually destroy the MAF sensor.

Fix: Install your Water/Methanol Injection nozzles behind your throttle plate and use a good solenoid close to your nozzles.

I hope that helps
Michael Plummer
That’s exactly what I was going to say!! Haha
 
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oilspill

oilspill

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Leaking down: Water/methanol fluid left in the nylon tubing is sucked out by the engine vacuum and this fluid flows or dribbles in the opposite direction of the engine/throttle plate.

Washing the MAF sensor: Under harder acceleration, the "leaked down fluid" gets picked up and is blown over the MAF sensor. Repeated cycles of this will eventually destroy the MAF sensor.

Fix: Install your Water/Methanol Injection nozzles behind your throttle plate and use a good solenoid close to your nozzles.

I hope that helps
Michael Plummer
Weird part is I have a solenoid…but it’s in the trunk.

I also replaced the MAF at one point and it still ran like shit.
 

Michael Plummer

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Weird part is I have a solenoid…but it’s in the trunk.

I also replaced the MAF at one point and it still ran like shit.
Solenoid in the trunk: The engine vacuum pulls the fluid out of the nylon tubing or line length. The bottom line, the solenoid should be placed close to your water/methanol nozzle. In your setup, you should have used two solenoids.

MAF: Once fluid hits the MAF sensor, your car will stumble and buck. The MAF doesn't need to die for it to have a driveability issue. And you could have other issues causing your bad driveability (easy to do when you add parts without a tune or don't know).

I hope this helps
Michael Plummer
 
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oilspill

oilspill

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Solenoid in the trunk: The engine vacuum pulls the fluid out of the nylon tubing or line length. The bottom line, the solenoid should be placed close to your water/methanol nozzle. In your setup, you should have used two solenoids.

MAF: Once fluid hits the MAF sensor, your car will stumble and buck. It doesn't need to die for it to have a driveability issue. And you have other issues causing your bad driveability (easy to do when you don't know).

I hope this helps
Michael Plummer
Appreciate the feedback man. You actually sold me this kit back in 2014 as part of a group buy on a different forum. Full circle a decade later after I finally installed it.
 

ttocs

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ah I see now with the solenoid in the back. Correct me if I am wrong but don't you want the nozzle in front of the AIT sensor?
 
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oilspill

oilspill

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ah I see now with the solenoid in the back. Correct me if I am wrong but don't you want the nozzle in front of the AIT sensor?
you would....i moved that sensor to the lower intake when i did the blower
 
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oilspill

oilspill

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Solenoid in the trunk: The engine vacuum pulls the fluid out of the nylon tubing or line length. The bottom line, the solenoid should be placed close to your water/methanol nozzle. In your setup, you should have used two solenoids.

MAF: Once fluid hits the MAF sensor, your car will stumble and buck. The MAF doesn't need to die for it to have a driveability issue. And you could have other issues causing your bad driveability (easy to do when you add parts without a tune or don't know).

I hope this helps
Michael Plummer
Michael

Can I use this check valve at the nozzle so I don’t have to run new wiring from rear of car for another solenoid or is that cutting corners?

C49178CD-A011-4AF7-B933-FDAAA3D87484.jpeg


Been sitting on my desk for 2 years.
 

ttocs

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mr plumber would be the expert here by all means but if I am thinking about it right I don't think so. It would prevent it from going back to the solenoid but the vac being drawn from the intake would still allow it to pulled out forward. I set up a meth system in my car but I have not filled or used it yet because of one thing or another but I will have to show you how I put my solenoid on the TB. It is a tight fit but it should work.
 
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oilspill

oilspill

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mr plumber would be the expert here by all means but if I am thinking about it right I don't think so. It would prevent it from going back to the solenoid but the vac being drawn from the intake would still allow it to pulled out forward. I set up a meth system in my car but I have not filled or used it yet because of one thing or another but I will have to show you how I put my solenoid on the TB. It is a tight fit but it should work.
that makes sense. believe the valve has 7psi crack pressure so assume vacuum would open that

I guess i should stop being lazy.
 

ttocs

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like I said it is a REALLY tight fit but there is just enough room for the TB to move fully and for the nozzle to be there.IMG_20230223_122004154.jpg
 

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