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> 2.0 plenum issue, Can it be removed while in the car?
robkammer
post Oct 6 2026, 09:05 AM
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Hello brain trust! The engine saga continues on our BB. What started in February as an engine reseal, head refresh, and engine compartment repair is still ongoing. The heads needed a full refresh, and close inspection found cracks, that the head expert 'fixed' with Timeserts. Lifter wear pointed to a cam lobe that was half gone. So off the short block went to a very well know Type I and IV engine builder. Wife and I went to Florida and wandered around for a month while this was all taking place. Back to Ohio in March and I started gathering the parts needed for the re-install.
The heads came back looking great, and the short block looked even better, now with fresh bearings, a stock cam and bearings, and a new oil pump.Oh, and we dicovered that I had a 2056, Cool, right?
Got the heads on, all of the tin, wiring and hoses. Put the beast in the car and started the break in process. First 30 miles, then oil change and valve adjust, then 100 more, rinse and repeat. Noticed a pretty significant oil leak coming from the front of the engine. it was the new oil pump, totally unacceptable. The builder came to my shop in hope that the oil cover gasket was the problem. Uh, no.
So out came the motor, back to the builder who is 100 miles away. At the 130 mile mark I also pulled the plugs to see how they were firing. All good, except that three of the Timeserts came out with the plugs, crap.
So while the engine was at the builder I ordered a new set of AMC heads, shipped directly to the builder. Why not, eh?
Get the engine back in with the new heads, start the process again. Got through about 65 miles and the engine is running like crap.
All of the FI bits are working as they should, and all with engine wires are Jeff b's harnesses. The only non functioning bit is the thermo sensor on the side of the plenum.
Plugs looked ok but maybe a bit on the lean side.

Time for a Smoke test! Cool tool for sure, brings back memories of my Lionel trains.

At first glance it looked like the throttle body shaft was leaking, although I had Rocky in Walla Walla rebuild it while the engine was out the second time. Nope, turns out that one of the two unused tubes through the plenum had somehow come loose and is allowing atmosphere into the plenum. I've attached a video.

So after that long intro about my sorrows, the question is: Can I remove the plenum while the engine is in the car? I struggled getting the intake runners onto the plenum the second time while the engine was on the cart, I used the 100 mile old rubber tubes and they may have shrunk. I'll buy new rubbers again, and of course the intake gaskets. But am I delusional that I may be able to get the plenum off in order to repair or replace it without dropping the engine, Again!!??

Any helpful advice will truly be appreciated.

Robbo
Attached File  smokin.MOV ( 3.06mb ) Number of downloads: 51



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robkammer
post Oct 20 2026, 01:12 PM
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Robbo
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Thanks. I typically pull the plugs at each oil interval to check the burn. Where would I mount the O2 sensor to feed the AFR? I would consider doing a stealth install for the gauges, but not mess with the stock console setup. Could the cht ring be mounted under the cht sending unit rather than the spark plug? And finally, maybe, if the motor was to run lean or hot, how would I tell the ECU to change the mixture?
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emerygt350
post Oct 20 2026, 02:10 PM
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QUOTE(robkammer @ Oct 20 2026, 02:12 PM) *

Thanks. I typically pull the plugs at each oil interval to check the burn. Where would I mount the O2 sensor to feed the AFR? I would consider doing a stealth install for the gauges, but not mess with the stock console setup. Could the cht ring be mounted under the cht sending unit rather than the spark plug? And finally, maybe, if the motor was to run lean or hot, how would I tell the ECU to change the mixture?

I made that console gauge setup custom for my stuff. The original 3 gauge face is safely stored away.

The cht sensor for the gauge needs to be on the plug for accurate and immediate readings. The location of the djet sensor is deliberately distant so it does not change as quickly and will not read as hot as the plug. You need to know what the valve seats are experiencing so the plug it the right spot.

The MPS is how you tune it to match the motor. However, you can cheat it by simply adding resistance to the wire leading from the cht. It works but not as well as tuning the mps.
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Posts in this topic
robkammer   2.0 plenum issue   Oct 6 2026, 09:05 AM
emerygt350   Hello brain trust! The engine saga continues ...   Oct 6 2026, 09:24 AM
robkammer   I need to fix that leak before going much further...   Oct 6 2026, 10:13 AM
JamesM   Sounds like a bit of an ordeal for sure Noticed...   Oct 6 2026, 10:47 AM
dax1969   Noticed a pretty significant oil leak coming from...   Oct 7 2026, 03:26 AM
Superhawk996   Noticed a pretty significant oil leak coming fro...   Oct 7 2026, 06:05 AM
JamesM   So while the engine was at the builder I ordered...   Oct 6 2026, 10:54 AM
robkammer   Hey Teeners, thanks for all of the replies. A coup...   Oct 6 2026, 04:08 PM
emerygt350   Just put a plain Jane fuel pressure gauge inline w...   Oct 6 2026, 06:15 PM
robkammer   Thanks Emory: Yes, stock ignition. Not going anywh...   Oct 6 2026, 07:16 PM
emerygt350   Thanks Emory: Yes, stock ignition. Not going anyw...   Oct 7 2026, 05:53 AM
robkammer   Hey fellas, here’s an update. I have the plenum ...   Oct 14 2026, 04:38 PM
emerygt350   Don't worry too much about the TPS. Just make...   Oct 14 2026, 06:50 PM
robkammer   Sounds simple, I guess my question is: How can I t...   Oct 15 2026, 04:28 AM
emerygt350   The wire closest to the passenger side is the idle...   Oct 15 2026, 05:49 AM
robkammer   Perfect! Thanks for the explanation. Plenum an...   Oct 16 2026, 08:09 AM
robkammer   Hey teeners, here’s the latest update; It runs...   Oct 19 2026, 06:12 PM
Jack Standz   [quote name='dax1969' post='3274415' date='Oct 7 ...   Oct 19 2026, 08:37 PM
Superhawk996   Thanks for sharing that supplier. Hadn’t seen t...   Oct 19 2026, 09:56 PM
Jack Standz   Hey teeners, here’s the latest update; It runs...   Oct 19 2026, 08:50 PM
robkammer   Hi Fellas: I do not have a CHT gauge, nor an AFR g...   Oct 20 2026, 07:43 AM
emerygt350   Hi Fellas: I do not have a CHT gauge, nor an AFR ...   Oct 20 2026, 11:51 AM
Jack Standz   Hi Fellas: I do not have a CHT gauge, nor an AFR ...   Oct 20 2026, 12:49 PM
robkammer   Thanks. I typically pull the plugs at each oil int...   Oct 20 2026, 01:12 PM
emerygt350   Thanks. I typically pull the plugs at each oil in...   Oct 20 2026, 02:10 PM
robkammer   Thanks. I typically pull the plugs at each oil i...   Oct 20 2026, 04:29 PM
robkammer   Thanks. I typically pull the plugs at each oil i...   Oct 20 2026, 04:31 PM
rjames   Thanks. I typically pull the plugs at each oil in...   Oct 20 2026, 04:55 PM
Jack Standz   [quote name='emerygt350' post='3275762' date='Oct...   Oct 20 2026, 04:57 PM
emerygt350   I am about 6 hours from you, otherwise I would lov...   Oct 20 2026, 07:15 PM


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