Engine sputtering after putting 2018 intake manifold

[Jordan Jacoby]

I just installed a 2018 intake manifold and got a tune by palm beach dyno the intake came with imrc lockouts. But my big problem is that the car is running horrible at idle it’s going up and down without pressing the throttle and when ever I drive off at a stop around 2000 to 3000 rpm the car sputters. thought I had a vacuum leak at first but I sprayed carb cleaner and found 2 vacuum leaks fixed them right up and thought that would fix it. Ha NOPE. So I thought maybe it’s in the tune I sent data logs over to PBD and their saying that there’s a vacuum leak am I the only dealing with this problem pls help

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[ice445]

If they said there's a vacuum leak then there is one, you can easily see it on the fuel trims and it fits the symptoms. You may have pinched a runner gasket or something isn't torqued properly. Recheck your work entirely from step 1.

 

[GregO]

Start over with a GT350 manifold.

 

[Jordan Jacoby]

If they said there's a vacuum leak then there is one, you can easily see it on the fuel trims and it fits the symptoms. You may have pinched a runner gasket or something isn't torqued properly. Recheck your work entirely from step 1.

What would the fuel rails read because I did a data log and it shows the fuel bank reading if you would happen to know?

 

[ice445]

What would the fuel rails read because I did a data log and it shows the fuel bank reading if you would happen to know?

Anything above 12% on long term fuel trim indicates an issue

 

[Firsttexan]

PBD has it right. All the Hallmarks of a vacuum leak. Pull the manifold. Do it over.

 

[Pistol_91]

If you created 2 vacuum leaks installing it you prob have more.

 

[SheepDog]

What would the fuel rails read because I did a data log and it shows the fuel bank reading if you would happen to know?

You are looking for STFT's (Short Term Fuel trims). anything above +10%. Start the engine and let it idle. view your STFT's, get some brake cleaner or carb cleaner and spray quick, short bursts around the throttle body, intake manifold, anywhere after the MAF sensor. You will know when you found the leak, when you see the STFT's fluctuate and drop to a - value. If the leak is large enough, the engine RPM will surge as the brake cleaner is sucked into the engine.

Since you have the IMRC's locked out, make sure that the vacuum port and the feed line are capped/removed. Take a couple pictures of your intake from various angles and post them

 

[Nitrofish]

Was the manifold ported ?

 

[illadvised]

Throttle body on correctly? I had a slight leak and taking off the throttle body and putting it back on fixed it

 

[5.0_Lojos]

Throttle body on correctly? I had a slight leak and taking off the throttle body and putting it back on fixed it

I am wondering if our cars need a "TB relearn" something similar happened to my daily driver (Nissan Pathfinder) When I had removed the TB. Good idea to remove, check and reinstall the TB. Im waiting on my recent order 2018 Mani.

 

[horsepower addiction]

Was this a used intake manifold?

 

[ice445]

I am wondering if our cars need a "TB relearn" something similar happened to my daily driver (Nissan Pathfinder) When I had removed the TB. Good idea to remove, check and reinstall the TB. Im waiting on my recent order 2018 Mani.

They do, but they do it automatically. 1 minute in normal idle and 1 minute with A/C on takes care of it.

Was this a used intake manifold?

This is a good point to mention, the manifold probably has a hidden crack somewhere that OP missed.

 

[5.0_Lojos]

They do, but they do it automatically. 1 minute in normal idle and 1 minute with A/C on takes care of it.

This is a good point to mention, the manifold probably has a hidden crack somewhere that OP missed.

Good to know

 

[Scott.Hull]

I know this is an old thread but what was the fix? Mines doing the exact same thing

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