Long time lurker, first time registration and poster

Have an 06 is250220k miles my brother and i just did the intake walnut blasting. Job went well used the boroscope to verify valves closed and went to town with the gun and the shop vac.

Car ran fine into the garage albeit low on power. Got everything back together, and while it starts, it immedietly dies. i can keep it running with manual throttling, but releasing the throttle and it stubles and dies.

No codes popping yet. 99% sure i got everything plugged back in properly, and i double checked.

Any ideas where to start? I do have a bidirectional scanner if i need to send ecu commands

Went back over my work alresdy and seems to be properly torqued and plugged

 

Make sure to double check all connectors are securely plugged in. The symptom almost sound like you may have a vacuum leak. Not enough of a vacuum leak to trigger a CEL, but enough to affect the idle.

Worse case scenario you had walnut media get into a cylinder. I'd check that scenario with a compression test and verify all cylinders have similar compression to each other.

These are just suggestions. You might have something completely different then what is described above. A Check Engine Light and corresponding code(s) would help guide the correct diagnosis.

Good luck!

 

I was very through about doing one cylinder at a time and verifying valves closed for each with a scope. Verified cleaned out with scope and excessive amounts of blowing compressed air with a rubber tube that can reach the entirity of the port. Im not perfect, and If any fell in, it would be a very tiny piece thats im sure would combust rapidly.

Def leaning to a vac leak, smoke machine is gone of course......

Any tips on sealing that pass side head vent to the intake? Real loose. Hate rtv

 

Yeah could be a vacuum leak. If so, I suspect an intake plenum gaskets could be compromised or misaligned.

As for the passenger side head vacuum hose that supplies fresh air into the crank, I'd use a worm gear hose clamp if you think the factory clamps do not allow for adequate sealing.

When I did my spark plugs I forgot to clip in the sensor on the driver side of the upper intake plenum (the white/tan plastic housing). The car idled terribly, but I was able to find the issue quickly once I did a visual of my work. Once plugged in, the 4GR ran like butter.

Good luck!

 

You can use propane to find a vacuum leak or if you're feeling risky a can of brake cleaner.

But the golden method is a smoke machine.

 

The trick to getting the driver's side pcv hose seated is to leave the intake plenum loose and lift the plenum carefully to expose enough room to seat the hose onto the pcv valve by hand, if you're not referring to the fresh air pcv side (passenger's side head).

My previous post kinda answers your question about the passenger pcv hose (use a worm gear clamp if the factory spring clamps aren't working for you).

 

Ended up being two fold issue, First to the vacuum leak. I missed that rear driver head hose altogether. It pulled off when i pulled the manifold and i never saw it come off, so i never put it back on. Thanks for saying that. It def had me perplexed until i took it apart for the third time lol.

Second issue was the plug on that rear driver valve cover. It had never seated fully due to a stray walnut chunk.

Thank you guys for your help very deeply.

 

You're very welcome. Half the time it just takes a small bit of suggestion to help another person achieve what seemed insurmountable!

Happy motoring!

 

where is this plug? What does it look like?