73 BB Smog Pump Diverter Valve 29190

[George H.]

Need help fining a service repair shop. I have the original A.I.R system on my 73 LS4 454 BB with M21 4-speed. Under acceleration and when downshifting, I'm getting backfiring. I assume the diverter vale is bad. It is stamped 29190. The air-injection pump back-plate is casting number 7801149. The pump is dated 13032S (05/10/73).

(1) Can this valve be repaired? If so, what service repair shop or person can I contact?
(2) The valve still has the round spot marking where the diverter usage label code was at onetime, "JH". Where can I purchase a replacement stick-on label? I appreciate any help.

George
gator943
Ocala,FL

[Gary S.]

Re: 73 BB Smog Pump Diverter Valve 29190

Look up Bill Hodel. He is the AIR guy.

Gary

[George H.]

Re: 73 BB Smog Pump Diverter Valve 29190

Thanks Gary, I will do that.
George

[Joe L.]

Re: 73 BB Smog Pump Diverter Valve 29190

Need help fining a service repair shop. I have the original A.I.R system on my 73 LS4 454 BB with M21 4-speed. Under acceleration and when downshifting, I'm getting backfiring. I assume the diverter vale is bad. It is stamped 29190. The air-injection pump back-plate is casting number 7801149. The pump is dated 13032S (05/10/73).

(1) Can this valve be repaired? If so, what service repair shop or person can I contact?
(2) The valve still has the round spot marking where the diverter usage label code was at onetime, "JH". Where can I purchase a replacement stick-on label? I appreciate any help.

George
gator943
Ocala,FL

George-----

It could be the diverter valve. If it can be rebuilt, Bill Hodel is one of the few guys that will be able to do it. You don't want to need to find an NOS example of this valve.

One thing to do first: inspect the check valves. These are the valves that thread on to the top of the manifold "trees" and to which the hoses attach. To inspect, remove them and blow through them from both sides. You should be able to blow from the nipple end but not be able to blow at all from the threaded fitting end. If you can get any air through from the threaded fitting end, the check valve is shot and needs to be replaced (I don't think anyone can rebuild these valves in a manner that's going to be reliable). In any event, if either of the valves is shot it will cause the destruction of the diverter valve and, usually, the AIR pump itself.

[George H.]

Re: 73 BB Smog Pump Diverter Valve 29190

Great technical advise Joe. I will follow your instructions and inspect the two check valves. Trust it is not a bad diverter valve, + check valve(s) and or a damaged pump. The engine just started to backfire about two months ago when I step on it. No issues with normal driving. I drive the car maybe 50 miles a month at best.

George