3.6l driveability issue

[danander11]

Heya, new member here.
2009 Buick Enclave, 3.6l, fwd.. bought not running.

Rebuilt the engine with the following new parts:
Balancer
Oil pump
All Bearings and seals
#4 rod
All new pistons, wrist pins & rings
All new gaskets
Coils x6
Plugs x6
Fuel Injectors x6
Water pump
Temp sensor
Timing set with new gears
VVT solenoids x 4
VVT cam sprockets 2x I, 2x E

Crank ground .02" rods and mains
Block cleaned and honed
Heads rebuilt

I've been away from wrench turning for almost 20 years, (living abroad), so I'm fairly unfamiliar with the newer systems.

The VVT stuff I changed because bearing material from the #4 rod was found occluding the screens.

Put it back together last week and got it started, but I'm having an issue getting it to run well.

It starts and idles fine, but gets unhappy when I get around 2k rpm or above.

Can't find any vacuum leaks. and sometimes smells like it's running rich.

Intake vacuum is running around 15", but drops to around 10-11 when revving up.

Occasional misfire on 1, 5,& 6.. but no CEL.

Scanner live data shows everything to be operating as it should, at lease as far as I know, but I may be missing something. The only values that are in the red are for the front and rear knock sensors..

I've disconnected the cats with no discernible difference, but I've ordered replacements along with a new MAF sensor. (We intend on keeping this as a travel car)

Suggestions?

Thanks!

 

[Mooseman]

Is your scanner capable of doing an injector balance test? Maybe you have some leaky injectors. Wouldn't be a bad idea to check fuel pressure too.

Have you looked at the live O2 sensor data? What are the trims like?

Other things to check are intake leaks and a dirty MAF sensor. Maybe the fuel is old/bad?

The only values that are in the red are for the front and rear knock sensors..

Are they detecting knocking and retarding the timing? If they're constantly triggering, you would think it would throw a code.

 

[danander11]

Is your scanner capable of doing an injector balance test? Maybe you have some leaky injectors. Wouldn't be a bad idea to check fuel pressure too.

Have you looked at the live O2 sensor data? What are the trims like?

Other things to check are intake leaks and a dirty MAF sensor. Maybe the fuel is old/bad?


Are they detecting knocking and retarding the timing? If they're constantly triggering, you would think it would throw a code.

Thanks Mm...

For some reason, my scan tool won't perform an injector balance test on Buick.. It will for the same year Traverse (same engine), just nothing for Buick.

I tried using the Traverse one but it says that the immobilizer won't allow it.. huh? Oh well.

No leaks that I can find, O2's look acceptable, I reset the fuel trim.

I've put new fuel in and cleaned the MAF sensor. I've also dropped the cats but none of that helped.

However, I tested the MAF with a multimeter and found what I think are odd numbers.

Batt/Alt voltage (Pink wire), and the ground, (Blk/Wht wire), are fine and as they should be.

Tan and light blue wires to the IAT are as they should be.

The Yellow wire (MAF SENS SIG), shows 5v Eng off and unplugged, 1.9v Eng off and plugged in, and 1.9v Eng running and plugged in.

Further the 1.9v plugged in and running does not change at all when throttling up!!!

I would expect it to increase as more air flowed across the sensor... and I'm not understanding the 5v unplugged.

I'm thinking, with my old and limited brain, that it is a bad MAF sensor regardless of the voltage.. that there is no voltage delta when the throttle is opened and more air going through tells me that it's not sensing.

Thoughts?

 

[mrrsm]

Is the Vehicle still sporting the Original Catalytic Converter? Perhaps it is clogged or has the internal Lanthanides (Rare Earth Metal Impregnation) Ceramic Core Fractured or Damaged. With the Engine Off, Parked & E-Brake SET... Put Down some Cardboard and slide nearby to the CAT and Tap on the Bottom of the S/S CAT Can with a Dead Blow Hammer. If there is a rebound Sound (something akin to Dropping Coins into a Ceramic Bowl) this would indicate having a Damaged - Restrictive CAT.

 

[danander11]

Thanks mrrsm,

I disconnected them to see if they were blocked, as I don't have a back-pressure gauge, but it didn't make any difference.

 

[Mooseman]

Maybe try using a GMC Acadia or Saturn Outlook for the balance test? Is your scanner one of the cheaper Chinese ones? Very strange.

Maybe try a compression test to verify that the timing chain was installed correctly and valves are sealing well. A mistimed chain/cam gear I would think would throw a code. For the misfires, try swapping the coils with those not showing misfires and see if they follow the coils.

 

[danander11]

Maybe try using a GMC Acadia or Saturn Outlook for the balance test? Is your scanner one of the cheaper Chinese ones? Very strange.

Maybe try a compression test to verify that the timing chain was installed correctly and valves are sealing well. A mistimed chain/cam gear I would think would throw a code. For the misfires, try swapping the coils with those not showing misfires and see if they follow the coils.

It's an Autel MY906BT and does well with most things, including my 958 Porsche. Just odd that Chev and Saturn are there for that year and Buick is not.. as they're the same. Also odd that the immobilizer is what won't allow it to run the Chev.

Haven't done a compression as it runs very well <2k rpm.. but I did pull the intake and valve covers to verify the cam timings with the alignment tools. Not to say that the crank isn't off, but looking at the keyway, it looks to be right too.

My fear is that the reluctor wheel on the crank has slipped. I was told about a TSB on these, but that was after the engine was assembled and installed.

The voltages on the MAF aren't to my liking so I'm waiting for a replacement to show up. If that isn't it, I'll pull the motor and pull the timing cover and start again.. but my gut is saying it's not that.

Thanks though.