My air pump is pissing me off to no end. The service manual is really fuzzy on how to diagnose air pump problems. My pump comes on when the engine is cold, and everything is fine. Then, "click" the clutch on the pump disengages, so I give the engine a little gas and, "click" the clutch grabs and works again, then 30secs later, "click" it stops engaging, and the process repeates itself 'till I almost explode with anger. I checked the terminals on the pump for continuity, it's ok. Then i checked the air pump relay, it's working fine. Please someone, anyone, help me find this problem. Is there anyone else with this problem? I really need to get my 7 up and running healthy again, it's my daily driver.

 

Remove the air pump and replace your cat with a mid pipe

 

I wish it were that easy. I'll still run rich at ldle, and I'll have to buy new spark plugs every week

 

why isnt it that easy? my undersatnding of the workings of an air pump must be wrong then. how whould running your air pump cause your ENGINE to run rich? i know it will burn out your cats if not running the airpump, how will it save your plugs? i dont understand the logic you are using here...please explain

 

Rxrotary2_7 is right, the airpump is only there to keep the cat alive.

 

thanks for the backup. i know i am not crazy.

 

Well, not everyone wants to run a midpipe and deal with the sound/smell (and some people still need to deal with emissions testing).

Swamp RX-7,

I would look on partstrader or some other place and get a used Air Pump for $50. From what I understand about the air pump, if it's going bad, there isn't much that you can do to fix it. You basically just need to replace it.

Grab another one and see if the same symptoms occur. If not, then you are fixed.. If they are still there, then you have at least ruled out the pump itself (and it's not a bad idea to keep a spare air pump around).

 

in reguards to emission testing. these are "bolt-on/off" mods that can be changed in a very short amount of time if need be.

how an air pump works---
The air pump reduces emissions when the engine is below 3800 rpm. Above 3800 rpm the main cat is hot enough without the extra air. The air pump pumps air into the exhaust and into the main cat to give extra oxygen for the pollutants to combine with and burn.

swamp- check out this site for more info http://www.rx7turboturbo.com/robrobinette/air_pump.htm

 

Correct, but if the air pump is not working now, changing it out for a midpipe isn't going to help if he does have emissions testing.

It will still need to work then...

But like I said, midpipes aren't for everyone. I'm sure he knows he can remove it, but he was asking for help on how to fix it, not alternatives for removing it.

 

If he removes the air pump he will run richer, mostly at idle. Takes a reprogrammed ECU to correct the problem.

 

jake- again, the last two words you quoted me on...please explain.

mahjik- i understand they are not for everyone...nevermind, its not worth my time

 

Like rxrotary2_7 was saying "please explain". Why would you run too rich at idle without the airpump? How does a reprogram ECU fix this? If you understood the function of the airpump from where and to it's pumping the air then you'll understand why you will not be running rich at idle. I can see that not a midpipe is not for everyone but since Swamp already has a high flow cat then I would get a new pump. Or sell your high flow and use the money to get a mp. No pun intended.



Tony S.

 

The Air Pump supplies air to the Air Control Valve (ACV) at idle and low RPM operation. The ACV can direct this air to 3 places, the split air pipe (which goes to the main cat), the lower intake manifold, or the atmosphere. At idle most of the air is being dumped right into the intake manifold which effectively leans the mixture. This is why people who remove the air pump often complain about bad idling. Leaning the mixture with a programable ECU is the only way to solve this problem. For those of you who have removed/disabled the air pump and have not corrected the idle mixture you should check your plugs often to make sure they have not fouled.

 

Jr explained it better than I could've.

 

jr- thanks for the explination. interesting. but does it affect anything other than idle? i dont realy care to much about my mixture at idle, and i always have and will change my plugs every 3rd oil change (about every 4.5-5k miles)

 

Well, I took my 7 out for a test drive today to see how it drove. With the air pump not working it still pulls hard and smooth, but when I let off the gas when at high RPMs the car begings to backfire really bad. My conclusion is that because the air pump is not working the anti-afterburn valve cannot function at all. I think I'm going to give up and get a midpipe and a super AFC to lean the fuel out at idle, and also program it to help with the backfire situation. Anyone else have any ideas? By the way, I live in louisiana, and we don't have emmision testing here, so a midpipe is cool to have, I'm just worried about the wastegate not being able to handle the higher boost.

 

Well, you're going to kill your cat if you run like that all the time.

Personally, I would just get a used air pump and stick it on the car. I dislike the smell midpipes give off. Plus, in my line of work, I can't smell like exhaust if I drive the car in that day...

 

I just bought a used air pump for 125.00, it had low milage. The thing is that it isn't the pump itself, it's the electrial system that controls the pump. I checked everything from the connector at the pump to the relay to the pump and everything checked out ok per the sevice manual. The only thing I can figure is that the ecu is telling the pump to shut off for some reason that I can't figure out. For once, I am completly stumped as to this situation. I'm an automotive tech and smelling like exhaust is no big deal when I go to work or school

 

Actually, that's usually how people tell when the air pump is going bad... It usually shuts itself off half the time until it shuts off for good.

Could be something else, but it really sounds like the pump has just had it.. Hooking up a new/different pump will let you know for sure.

 

Today I went about as in-depth as you can when it comes to figureing out problems with the air-pump. I went to the back of the ECU and checked the wire that goes to the air-pump, it's ok. So, I spliced into the wire at the ECU to test the continuity of the wire from the ECU to the relay. It was fine. I then checked the wires going to the pump itself, they were fine according to my volt meter. Using the electrial diagram from the sevice manual was somewhat helpful. I found the EGI relay supplies power to the air-pump relay. So, I looked at the EGI relay and fuses, they were fine. I then tested the pump itself, I put 12v direstly to the pump and the magnetic clutch engaged like it should. Next, I pulled the cover off the air-pump relay and started the car. The pump was working fine, then, "click" the pump shut off. I gave the car some gas and the pump turned back on, good. Now, I set my sights on the relay, with the cover off I'm able to see the relay switch move from open to close. The relay stayed in the closed(on) position, then, "click" it went to the open(off) position. Next I took the relay out and applied 12v to it and the relay clicked on, I held power to it for some time to see if it was up to the task. It was. It worked fine. Now I'm in my garage cursing like a sailor! WTF! Everything works out the way it is supposed to, is there a phanton under the hood of my 7 making the pump stop? I don't know what to do, I don't have the money to run out, get a PFC and a midpipe and call it a day. Arghhhhh!! I'm soo pissed. Please fellas, point out something I may have missed. Sorry for the long post.

 

again, i dont know much about the air pump due to just ripping the thing out and being done with it. but from your explination of your troubleshooting, it sounds as if when you put 12v to it, it works fine. maybe if you run a continual 12v to it from a source that has 12v only when the car is on, it may solve your problem. just bypassing the signal from the ecu (even though you said it was good) other than that, the statement you made about giving it more gas and it turned back on, in combination with the 12v straight to it, would make me personaly think to check your battery and alt. maybe your battery doesnt hold a strong enough charge, or your alt isnt charging properly (maybe due to a loose belt) or something to that effect? i know my alt doesnt charge well at idle due to a larger pully on the alt. (shown by the lights dimming out at idle, and comming on strong when i give it gas) i dont know...just a few thoughts to try to help you out. but i am probobly wrong....

 

Not sure if you want to operate the air pump continuously. I think the system disengages above ~3800 rpm, and the bearings in the pump will probably wear out fast if you let it run up to the red line.
-MP

 

Ok.... did you hold a volt meter on the wire comming from the ECU sending the signal to the air pump relay? Is it still sending a charge when the air pump shuts off? If not then it's your ECU telling the AIR pump to shut off. If it's still sending a signal then send 12v to the air pump relay for an extended peroid of time and see if the relay still turns off on it's own. In that case it would be your air pump (possibly just the relay)
It is possible you have a prob w/ your ECU.... dosn't mean you need a PFC but you could get a used ECU in that case.

hope that helps a little

 

As far as I can remember, my air pump cycled itself on and off, too. Don't really have much else to add since everyone has chimned in pretty well

 

i didnt even think about what i said about running continual 12v to it. wasabi may be right. but there is a way to have it stop working at a certain point. i know turbonetics and other places sell devices that send a signal ( i believe a ground) when a certain boost presure has occured. you may be able to look into one of these and figure out at 3800, what boost you are reading and set up something along those lines. again i am probobly wrong, but just giving ideas...