Resolved 1G Intake Manifold on a ported 2G 4G63t – Idle Issues & Adjustments?

[LA_gst]

Hey everyone,

Finally got my car back up and running (sort of). The mechanic installed a 1G intake manifold along with a 1G throttle body, but everything else remained from the 2G setup, including:

2G EGR system
2G Idle Air Control Valve (IAC/ISC) (brought over from the 2G throttle body)
2G Throttle Position Sensor (TPS)
2G MAP sensor
2G vacuum lines & solenoids
2G fuel rail & injectors
2G coil pack & ignition system
Stock MAF & intake system
All original 1G gaskets used for the manifold & TB

Now, I’m dealing with an unstable idle. The throttle body adjustment screw is practically closed, and the TPS was rotated back and forth to get the best possible idle. But it's still not quite right.

This is the start of the car after adjusting it.. It idles harsh but then idles normally after it warms up for a while. But then after you drive it it goes back to the rich idleing

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[RamenPride]

Now, I’m dealing with an unstable idle. The throttle body adjustment screw is practically closed, and the TPS was rotated back and forth to get the best possible idle.

The 2g TPS contains the closed throttle switch. There are specific instructions on how to adjust it.

 

[pauleyman]

The 2g TPS contains the closed throttle switch. There are specific instructions on how to adjust it.

Exactly. You can't just adjust TPS anywhere you want. Even more so on a 2g.

 

[LA_gst]

Exactly. You can't just adjust TPS anywhere you want. Even more so on a 2g.

Thank u guys..I'll bring this up to my mechanic n report back..

 

[pauleyman]

Do you have a recirculate BOV and what did you do with the MAP sensors since 1g manifold has no provision for it?

 

[LA_gst]

Exactly. You can't just adjust TPS anywhere you want. Even more so on a 2g.

Do you have a recirculate BOV and what did you do with the MAP sensors since 1g manifold has no provision for it?

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Do you have a recirculate BOV and what did you do with the MAP sensors since 1g manifold has no provision for it

The MAP was placed on top of the intake manifold..if I'm not mistaken..I have a picture

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[pauleyman]

I see a very blurry picture of the ignition transistor.

 

[LA_gst]

My apologies.. will ask my mechanic

 

[chrysler kid]

you cant use a 1g intake manifold on a 2g cylinder head. the 1g intake gasket was nowhere close to fitting on my 2g. it caused massive vacuum leaks

My apologies.. will ask my mechanic

Why don't you ask the mechanic to join the forum? He doesn't seem to know what he's doing.

 

[LA_gst]

you cant use a 1g intake manifold on a 2g cylinder head. the 1g intake gasket was nowhere close to fitting on my 2g. it caused massive vacuum leaks

The head was ported when I bought the engine. It matched the port size of the 1g manifold..I am also using a 1g OEM head gasket and a 1g TB..

Will see mechanic on tomorrow.

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[LA_gst]

Do you have a recirculate BOV and what did you do with the MAP sensors since 1g manifold has no provision for it?

Fount the map.. mechanic connected it to a type of vacuum line ..

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[LA_gst]

You cant use a 1g intake manifold on a 2g cylinder head. The 1g intake gasket was nowhere close to fitting on my 2g. It caused massive vacuum leaks.

Car is working in near perfect conditions. Resolved the idling issues. I'll be the first to say you can put a 1g intake manifold and 1g throttle body on a 2g ported head.

Do you have a recirculate BOV and what did you do with the MAP sensors since 1g manifold has no provision for it?

Fixed my idle issue. Turns out the build was good but the throttle body was bad. Internal leaks but car is running perfect. Thanks for all your advice.

Problem solved. Had the throttle body rebuilt and recalibrated the TPS..

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