Mechanics

HAVING ISSUES AFTER MOTOR SWAP

2004 Chevrolet Colorado

The truck: stock 04 Colorado z71 2wd
Stock motor: l52 3.5l 5 cyl 143 k miles

The replacement: stock 08 llr 3.7 5cyl 13k miles (per seller)

Using 04 pcm flashed 07 stock tune with custom tune to adjust for maf scaling.

The rundown: using 04 pcm and harness, all 04 sensors, 04 fuel rail, 08 injectors, 08 injector harness, 04 ported throttle body, 07 exhaust reluctor/actuator.

What we know: stock 07 will drop in to an 04 and run on the 04 tune and sensors.
04 and 07 exhaust reluctor are 5x. 08 is 4x. 08 lacks an intake cam sensor. One was we added one to the head in the proper location.
mechanically this motor resembles an 07 perfectly.
Compression is over 155psi, all timing marks line up correctly at tdc, coils check good, all sensors have proper resistance, only obd2code is p0300 random misfire (also pending)

The symptoms: truck will fire and run but will misfire constantly. Rpm will hover around 600+ which is normal idle rpm. Metallic sound coming from valve cover thought to be the timing chain. Tensioner is set and functioning, exhaust reluctor positioned correctly.
Mechanically and electronically this motor should be perfect.

What else can I check or is there something I have missed?
Avatar
Xkmacx86
May 6, 2012.




Ok this has been buggin g me and I just looked up the wiring schematic and the 08 engine DOES show a camshaft sensor. They are in the front of the engine. It also shows a camshaft actuator solenoid. I'm sending a pic of where the cam sensors are supposed to be located. This may be your problem with the rough running as you only have 1 sensor and need 2 or the one sensor may need to be moved to the normal 08 position to get correct timing. I am only going by the charts and schematics that I am reading but I think you'll see what i'm talking about.
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Tiny
Hmac300
May 12, 2012.
I added a 07 intake cam sensor. The motor physically and electronically is now 07


Tiny
Xkmacx86
May 12, 2012.

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