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Discussion Starter · #1 ·
I'll raise my hand first. I spent 3 months of weekends trying to solve this issue. My engine began hitting a wall at WOT doing 4K rpm. Almost like a rev limiter I never had! I began with ignition by examining cap, rotor, coil, wires, plugs. Nothing. Then moved on to carburetor. Checked fuel filter, air horn for warpage, air horn gasket for tears, base gasket leaks, air valve interference, power piston stiction, throttle cable adjustment, etc., etc., etc.

Finally I remembered I installed a fuse protected 12v feed line for an electronic ignition upgrade 5 years prior. Sure enough a 25 cent fuse was the source of my exasperation. Ignition was functioning on the original 6v resistor wire I left in to act as a "limp mode" feature. New fuse and voila! Back to normal. Geeeeze. I guess I really over-thought that one or my mental powers are diminishing with age!

Anyone else have a humbling saga to share?
 

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Discussion Starter · #6 ·
Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car righ
Uh........yeaaaaaaaah. i went through it this past summer and pretty much wasted the whole summer. Will provide details soon, but it relates to my thread in the engine section.

But one of the first rabbit holes i went down was:

Smoke billowing out of the right exhaust pipe only (true dual exhaust with no crossover).

i actually took the right side head off thinking it was a blown head gasket and replaced the gasket. Still doing it.

Tried another engine i had in the shed. Same problem. Is this a problem that affects small block chevies? The right side head gasket goes bad???????

Somehow, i had either knocked the vacuum modulator line off/or i did not attach it securely. During another road test i noticed that the trans wasn't shifting right, but there was no more smoke coming out of the exhaust pipe.

It turns out the vacuum modulator was bad---it was allowing trans fluid to leak and be drawn into the intake, and if you look at most SBC intakes, the vacuum connection for the modulator is usually on the right/passenger side of the intake----which likely causes the fluid to eventually go to cylinders 6 and 8, which would cause smoke to come out of the right side exhaust IF you have dual exhaust.

Proper diagnosis is the first step in fixing a car right.
D.B.....on the bright side....it's great you were able to escape out of that rabbit hole from 1971!
 
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