ABV not working? Desmog? (1 Viewer)

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Joined
Apr 19, 2004
Threads
18
Messages
123
Location
Colorado
My deceleration popping noise is due to a non-working anti-backfire valve. I disconnected and plugged the hose that goes to the exhaust manifold air injection rail and I no longer get the popping noise. The engine also seems to rev up and run a lot smoother but maybe I just like the fact that I am no longer getting the popping. Replacing it does not seem like an option (expensive, hard to find).
I have the ABV off the vehicle. I tried testing it by blowing though the intake, then applying vacuum and the air continues to flow out the output. I am pretty sure this means the ABV is defective.

My question is, should I desmog? I would like to have a clean running engine but I have a feeling I could have the motor running cleaner and more efficiently if I desmog. I dont need to go to the sniffer ever again.

I have seen diagrams to desmog but are there any online guides that step you though the process? I have heard that to do it properly you need to re-curve the distributor and make some kind of adjustments to the carb. I have rebuilt my carb and I put in a HEI so I think I can handle this part.

I have the 77 high altitude emmissions setup according to my Haynes manual (pg 90, Fig 3.106)

I have done a search and I cannot seem to find a page that gives all the details and procedures.
Thanks for any help or suggestions.
 
I will probably just desmog. I will need to do some more research before I attempt to do it.
In the mean time, can I just remove the Air Rail, ABV, and Air Pump without making other changes? I dont really know what to do with my broken setup right now.
Thanks.
 
I took out the smog pump, air rail, and ABV. WOW, what a difference. Something was seriously wrong with my setup because the motor sounds better at all rpms and has a lot more power. No more sputtering on decel. One thing I noticed was one of the pipes coming from the air rail that feeds air into the manifold was broken and was definately. Maybe that explains the lack of performance and high temps under the hood. I am very happy and I have a new pile of junk to find a place for. Now to tackle those mountain passes at over 45mph :):)

I love the way it is running right now but I was just wondering if anyone knows if there is something I should do to the carb or dizzy after this modification.

Thanks for everyones help.
 

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