AIR pump delete help needed

So I failed the Texas state inspection test because my 96 RMW had a dtc code 0410, which is the secondary air injection system or smog pump.  Trying to research this I found the TSB for the AIR pump disable. This would probably do the trick except that it requires the PCM to be reprogrammed, which I don't have the capability to do myself (as far as I know). Just for kicks I called the Buick dealer and they want $250 to do it. Seems like too much money, I'd much prefer to spend less $$$!

I suppose I could dive in and try to trouble shoot the system and start replacing parts. I thought I had it licked when I initially found a small plastic elbow coming off the left side air pump tubing that was broken off. It connected a small vacuum tube to a small electronic piece. I figured this must sense when the system is pressurized and when it doesn't sense pressure, it says the system is malfunctioning and trips the 0410 code. I fixed the elbow so the system is intact again and apparently my theory was wrong. I had disconnected the battery to reset the PCM and after two trips the check engine light came back on. Arghh.

Any suggestions would be much appreciated!

Do you hear the pump come on when you start the car? The TSB was released because the pumps usually fail due to moisture getting in them. If you want the AIR system disabled you can send the PCM out for programming which is a lot less than the dealer wants. As far as I know there's no cheap way to program it yourself like an OBD I car.

That sounds like a good idea. Do you know of any good places to send it to? I've never removed a PCM before, how involved is that?

One of the popular ones I hear of is pcmsforless. I have never used one of them personally, so can't recommend one. Removing the PCM is easy, remove the air cleaner housing and the pcm is in a tray under there. 2 clips hold the tray together.

thanks for the tip!

if you pull the pcm make sure to disconnect the battery 1st

95BRMW wrote:

One of the popular ones I hear of is pcmsforless.  I have never used one of them personally, so can't recommend one.

I can recommend him, as I had him program, probably about 5 years ago. He did a good job. If I remember correctly it was around $140 for a complete tune.

Tom

PCM reprogram looks like it will cost at least $175, being a cheapass I figured I'd take a stab at fixing the AIR pump problem before doing that. It has really got me stumped. With the tow package fan, it is impossible to hear whether the pump is running by just listening and there is so much air movement under there, you really can't feel if there is air coming out when you disconnect the hose. I removed the pump and bench tested it, works fine and no evidence of water in there. I tested the connector to the pump with the engine running and it does have power running to it.

So, ???  Evidently it is working and the computer is incorrect saying it is malfunctioning. I'm not sure how the car detects it is not working. I assume it is that small hose coming off the main air output hose that leads to something small and electrical. Maybe that sensor is bad?

Is it possible to have a relay that sends current when the connector is off, but when it has an actual load on it, it doesn't work?

I'd love to come up with the cheap solution, but sending the PCM out is looking more likely!

The computer isn't "incorrect." If the pump itself can run, it doesn't mean the system isn't malfunctioning. GM didn't put out a TSB to disable the AIR pump because it was cost-efficient to keep fixing the AIR system... Just spend the money on reprogramming the PCM. You'll get more power, better mileage and can address other areas at the same time (vary the shift points, transmission line pressure, disable rear O2 sensors, disable VATS). If you plan on doing gears or changing tire size, specify it in the tune so you only have to send it out once.

pcmperformance.com is good, as well as pcmforless.com.

Also, buy a Factory Service Manual (FSM).

Or... take off the fan belt temporarily. It is winter, after all.

If your AIR pump unit still works, you can buy the check valves for like $8-10 a side. It may take a torch and some convincing to get them loose, but the AIR system on the LT1 is cheap to maintain.

Check the integrity of the rest of the rubber hoses in the system, and you may find why you're getting the code.

And yes, get a set of factory service manuals. These cars are almost 20 years old - they require a hands-on owner.

sherlock9c1 wrote:

Or... take off the fan belt temporarily.  It is winter, after all.  

If your AIR pump unit still works, you can buy the check valves for like $8-10 a side.  It may take a torch and some convincing to get them loose, but the AIR system on the LT1 is cheap to maintain.

Check the integrity of the rest of the rubber hoses in the system, and you may find why you're getting the code.

And yes, get a set of factory service manuals.  These cars are almost 20 years old - they require a hands-on owner.

And having the help of some very sharp forum members helps too!  

jasonlachapelle wrote:

The computer isn't "incorrect." If the pump itself can run, it doesn't mean the system isn't malfunctioning.  GM didn't put out a TSB to disable the AIR pump because it was cost-efficient to keep fixing the AIR system... Just spend the money on reprogramming the PCM.  You'll get more power, better mileage and can address other areas at the same time (vary the shift points, transmission line pressure, disable rear O2 sensors, disable VATS).  If you plan on doing gears or changing tire size, specify it in the tune so you only have to send it out once.

I'm sure that's good advice, but I do have a question about reprogramming that I've always wondered. I've heard people saying that it will give you more power, better mpg, etc. What I wonder is if that could be gained from simple tweaking on the computer, why didn't the manufacturer design it with optimal programing to begin with? Isn't it in their interest to have the engine get the most power and efficiency possible with the stock hardware?

I do understand it of course if you are making mods like axle ratios, different tire sizes, internal engine changes and whatnot. For this car, I really have no plans to mod it from stock other than the Bilsteins I already installed.

Quote :

Isn't in their interest to have the engine get the most power and efficiency possible with the stock hardware?

No, because the manufacturer has to meet strict emissions requirements under a very tightly controlled environment. There is a reason why most LT1 wagons have 2.56 gears, and it's not because they are awesome on the highway at 120mph.