My suggestion to everyone is two books that should be standard fair in all of your libraries (mine are usually in the "john", which is where I do most of my reading). The subject matter of both is tuning and modifying ford fuel injection systems. Most importantly, they go through the basic systems, components, and what each of them does.

The answers to many of these type posts are in both books and I keep seeing posts like this and many times there is miss information. For instance, the "cooling effect" that has been suggested does not come from thermactor air, it is a function of the EGR system. Inert exhaust gas is metered into the combustion chamber by the EGR valve to "dilute" if you will the combustion mixture to reduce NOx emissions and the side effect is reduced combustion temps due to introduction of that inert gas which does not burn. The thermactor air is injected into the exhaust port during startup to help burn residual fuel that did not ignite in the combustion chamber during rich cold starting and running conditions until normal operating temp is reached. This also increases exhaust temp since it is introducing additional oxygen which from the heat of combustion allows the unburnt fuel to ignite. The second function is to quickly heat up the catalyst in the converter to get it to optimum operating temp which the increased heat in the exhaust attains. Once normal operating temp is realized by the ECU, the thermactor air is diverted from the engine to the converter itself and no longer goes to the engine. In certain circumstances the air is vented back to the atmosphere and doesn’t go to the port or the cat. In summary, thermactor is only for emissions, to help lower NOx and to help heat up the cat after start up.

It’s all in the books guys, I don’t just dream all this up, so if you don’t believe me, you can read it for yourselves in the books.

 

Presumably one of the books is Charles O. Probst's book on Ford EFI. What's the other one?

 

well, i know ive never had any trouble with my truck getting warm when i put a load on it. over the 4th of july, i towed a trailer with 3 dirtbikes, and had a load of insulation in the back up to my friends cabin, and had to use 3rd gear up a few hills and my temp gauge never moved a bit. it was also over 100º outside and i had the AC going. not having an air pump or cats doesnt cause me any problems.

 

I do this for a living, I've got more manuals then I can fit in the bed of my truck. Both of Probst's Ford EFI books are good for beginners. I agree that everyone should own them. Once you get your hands dirty, and know a few things, move up to Mitchell. Yes, the EGR does have that effect. I never researched the science of it, but I have seen many, many cases where the engine runs hotter after eliminating the smog pump. It could be because the cats are becoming clogged as a direct result, I never did an official study to see if each case of a warmer engine was one where the fool didn't pull the cats. It does happen though, like it or not.

Take care,
~Chris

 

thanks for your help. good answers, i never knew the basis behind it now i know. sorry i didn't respond faster i was out of town working. now i just need to decide if i am feeling like being legal or illegal

 

My suggestion to everyone is two books that should be standard fair in all of your libraries.


I agree. Knowledge is power!

The two books I recomend are:
"Ford Fuel Injection & Electronic Engine Control" by Charles Probst

"How to Tune & Modify Ford Fuel Injection" by Ben Watson


Both are good but Probst is a Automotive Engineer and his book is better and bigger!


I would NOT recomend the Mitchell products. They are fine for commercial shops because they cover all models and makes (This is their main selling point) but the proper Ford Helm shop repair CD's are the best. Cheap to find on E-bay or elswhere. They average almost 400 MB in size per year! Ford started putting these out in 1992 so they cover most models. I have each year from 1992 to 1998 and am looking to trade with anyone who has any of the later model year versions up to the current year.

 

I recently removed my air pump...about 4 months ago acutally. Haven't had any side effects with it gone.

I run a high flow cat and EGR and the truck runs better now than it did before. I went from a 905 length belt to a 858 length...I have ASP 3 piece pulleys. I didn't get an extra idler pulley or anything just removed the air pump and tossed it in the garage.

 

I have considered removing the smog pump on my '88 F-150. A few years ago it sounded like the bearings were going out and the belt was squeeling. I replaced the belt and sprayed some good ol' fix all PB Blaster on the pump. Perfectly quite after that, but some time later I saw the belt was no longer fully seated in the smog pump pully. That pully is out of line with the rest and the belt runs right on the edge. I can't figure out what could have caused this but it's been fine for thousands of miles. Ever seen that before?

 

I replaced my smog pump when I built my engine 3yrs ago. After installing the new pump I had to shim the pully out about .080" to get the belt to run straight.