89 r3500 building heat

[tinse4]

The truck is an 89 R3500 with TBI 454. It has an O2 sensor. That's why I'm concerned. If it were carburetor I would just adjust the carb to make up air fuel ratio.

 

[Georgeb]

I believe the AIR was intended to add oxygen to the cats to help them light off when the mixture didn't allow enough oxogen to them after combustion. If you are really concerned about that tipping the scale of passing or failing you could use some e85 to reduce the initial hydrocarbons. Others myself included have passed with this method.

 

[Georgeb]

I believe the AIR was intended to add oxygen to the cats to help them light off when the mixture didn't allow enough oxogen to them after combustion. If you are really concerned about that tipping the scale of passing or failing you could use some e85 to reduce the initial hydrocarbons. Others myself included have passed with this method.

This may be incorrect. They may use the AIR to fake the O2 to think the truck nees more fuel thus warming up the cats faster. Once warm it my not be operating anyway. I don't know how your system works.

 

[tinse4]

I am not 100% I am sure someone can speak more intelligent than I about it. One the AIR is mounted to the top of the manifolds on each side. My O2 sensor in just after the manifold in the driver side exhaust pipe. The pump is engine driven. I understood it was to add air into the exhaust to "help" lower emissions. Now if that is by leaning out what the O2 sensor read, or just by adding fresh air I am not sure. My mind tells me if I remove that fresh air it will change the O2 sensor reading. This should in turn lean out the air fuel mix to bring it into spec. I am sure with the crude computer set up it only has marginal ability to tune the mix. I suppose I can try without it, and if it fails add them.

 

[highdesertrange]

well I don't know where I got '73. ok A.I.R. was around long before cats. it is supposed to burn unburnt fuel in the exhaust manifolds by injecting air. I don't believe it. if it does anything it slightly dilutes the exhaust so that it seems to be running cleaner than it actually is. highdesertranger

 

[tinse4]

That is my understanding also. I guess we will see. It will be put on hold a week or two now. I just had a job come in that will tie up some funds. When it all wraps up I will tackle the exhaust. I will order the fan today, and see how that turns out first.

 

[tinse4]

So a late update. The temps are back up in Az. The truck runs great and cool while in motion regardless the speed, ac on or not. Now it is getting hot while sitting in traffic with the ac on. This is the complete opposite of what it was doing. So what I have done since the last post: ac compressor went out, so all new ac components to include the condenser. New clutch fan set up and new 3 row radiator from a 4 row. Cant find a shroud to fit the 34"x19" core on this so modified on the best as I could. Now i think the condenser was blocked, causing the compressor to go out, and causing a lot of heat in front of the radiator. This is why it was getting hotter going down the road. Now I think the issue is not enough air movement while sitting in traffic due to crap shroud, and fan clutch. So plan "w". going back with dual puller fans with a built in shroud. They claim 4600 cfm at 35 amp draw. They should be in tomorrow and installed on Saturday. Next step is a 4row aluminum radiator.I would really like to get this behind me to move on to other things with this truck.