2008 2.7L Tacoma Won't start after intake manifold reinstalled

My tacoma won’t start. The starter sounds good trying to turn it over, but I can’t get combustion. No codes are being given.

Full background:

I removed the intake manifold to replace the leaking coolant bypass line. I noticed a lot of gum in the intake manifold and in the block. I used non-chlorinated carb cleaner to clean the gum out of the intake manifold and block. I had to wipe a lot of it out and used 2 cans of carb cleaner. The intake ended up staying off for a few days, so all solvents should be evaporated. I replaced the intake gasket and vacuum line thats hidden on the back of the manifold.

I cleaned electrical connections, and I’m pretty sure I got all the harnesses and vacuum lines back on, as I’ve searched multiple times.

I had to disconnect the wiring from the ECM to get the intake in and out. I cleaned the connections and put them all back.
After putting everything back, I wouldn’t start. It tried to at first but sounded really rough and failed. I tried resetting the throttle body with the accelerator and tried starting with the accerator floored to give it air while cutting gas. This along with intermittently pressing the accelerator got it going. The first time I had to keep playing with the gas pedal to keep it alive. The second time I got it to idle almost normally but then it cut out abruptly. (I had this issue before from a jerry rigged negative terminal ground that the last owner did, so I got parts and fixed it.)

I pulled the spark plugs and they were covered in carbon, and the porcelain looked burned so I replaced them.

With better ground and new plugs, I can’t get it to combust at all. The starter sounds good. The throttle body kept making weird humming sounds with the keys turned to on, but this stopped after I went through the resetting motions, and still no start. I popped the fhel line open again and fuel ran out, so its getting fuel. There are no codes bring thrown. I am at a dead end.

Is there a common issue under these circumstances that could cause this? Thanks

 

Did you use carb cleaner on the hot wires of the mass air flow sensor and temp probe? Did you stick the tube down far enough to contact the wires? Only electrical cleaner should be used there, not carb cleaner and they don't like to be touched.

 

Did you reconnect the fuel lines correctly? It seems like they can be reversed and I know it won't run if they are.

 

I’d do that..

 

Fuel lines are correct. I took pictures along the way during dissassembly to reference later.

 

I didn't use carb cleaner above the throttle body at all. Is the mass airflow sensor and/or temp probe located below the throttle body in the actual manifold? Thanks.

 

Pop a coil and see if the tip is covered in oil or dry.

 

I already installed new plugs
and tried again with no luck.

These are the old ones in the picture

.

 

Just realized I didn't address the trouble shooting side of your suggestion. The tips didn't look wet, but there was a lot of carbon build up. I expected that since it ran like crap when it first started. I should have mentioned that I sprayed carb cleaner into the throttle body when I got it to run the first couple times, and I think thats what helped the engine start. I haven't done it since fixing the battery ground connection and replacing the spark plugs.

 

It would be nice to try new coils.

 

Located right after the air cleaner box.

 

*FIXED*
I tried a code reader again and this time it gave a code for the crankshaft position sensor. I looked at the wire going down to this sensor ( located behind AC pump) and noticed a connector for it further up the wire by the intake. I put pressure on it and heard a very faint click. The truck started perfectly fine, like there were never any issues. I drove it for 20 minutes on the highway with no issues.

 

Well done!

 

EXCELLENT!!!!! Glad you didn't rip it all apart again just to figure that out.