'76 Air Bypass Valve (ABV) rebuild ideas? (1 Viewer)

[dlobster 18]

Hello Mud Nation! I'm a newb. Had a '72 back in the day, and bought a '76 about a year ago to relive the glory days.

Recently replaced the smog pump. (housing cracked.)

Engine is now starting hard & have smelly exhaust. Guessing it's the ABV. Would rather not bypass the smog pump.

Can't find any aftermarket options, and would rather not buy a used one that may not work for $90.

I know these aren't build to be opened up, but am willing to try. Don't know much about how these work, but willing to explore . . . .

Any ideas are greatly appreciated!

 

[fjc-man]

Fiddle with the valve assembly a little, might just have shrapnel pieces from the old air pump stuck in it obstructing operation. Is your air pump replacement a rebuilt?

 

[dlobster 18]

Fiddle with the valve assembly a little, might just have shrapnel pieces from the old air pump stuck in it obstructing operation. Is your air pump replacement a rebuilt?

Thanks for the idea; bought a replacement from Parts Geek- manufactured by Dorman.

 

[SteveH]

Engine is now starting hard & have smelly exhaust. Guessing it's the ABV.

Have you started the engine with the ABV installed on the manifold end but on the inlet/pump end, and felt exhaust shooting out - that would indicate an bad ABV? IIRC, the ABV is just a check valve to protect the smog pump. Smelly exhaust on a pre-catalytic converter FJ40 is hardly an indication of anything amiss . Also, an ABV should have zero impact on starting.

 

[dlobster 18]

Engine is now starting hard & have smelly exhaust. Guessing it's the ABV.

Have you started the engine with the ABV installed on the manifold end but on the inlet/pump end, and felt exhaust shooting out - that would indicate an bad ABV? IIRC, the ABV is just a check valve to protect the smog pump. Smelly exhaust on a pre-catalytic converter FJ40 is hardly an indication of anything amiss . Also, an ABV should have zero impact on starting.

 

[dlobster 18]

Will give that a try- thanks for the idea & info regarding starting.