Air Pump, Pumps backwards? Doesn't engage clutch when running at any RPM.
 

Well I've done some searching to no avail. My air pump won't trigger while the car is running.

I have done these so far.

- Checked continuity from the PCM to the air pump relay- ok
- Unplugged the air pump and check continuity on the pump connector- 5.0 ohms
- When the key is turned to the on position the clutch clicks on and off, start the car does not engage again. It did try once or twice to engage and the car ran like shit when it did.

So I unplug the air pump and start the car. Apply power to the magnetic clutch to make the air pump run and it's pumping air out of what is supposed to be the inlet pipe. I'm guessing the PCM decided not to trigger the air pump again since it was sucking air from the ACV.

The only thing I can think of is someone had this air pump apart and some how put it back together backwards? I did just buy it from a forum member.

If I can get it to pump the right way, I still need to know what I can do if it won't trigger while the car is running. I know it is supposed to run below 3200rpm's and cut out after that. I also know that if the heat hazard sensor comes on it will shut the air pump off as well. I had considered this but the heat hazard sensor light is off so I'm guessing that's not it.

Any help would be much appreciated

Anyone?

Guess I'll be solving this one on my own. I will let you know If I figure it out.

Sorry man, don't have a clue on this one. I'll ask the shop I take my car to and see if they have any ideas.

Thanks, would really appreciate any input!

I'm guessing that it is not pumping backwards, but it is being driven backwards (you say it will not engage, so it's freewheeling) from air pressure out of the cat or other source.

The pumping happens when I jump the relay to engage the clutch. So the pump is spinning in the direction of the motor and air is coming out of the inlet pipe, in pulsations.

Then my 2nd guess is that the pump is worn out or the vanes are stuck and air is flowing backwards despite the pump spinning correctly. IMO, there is no way to assemble a vane pump backwards.

Guess I will pull off the outlet tube and see what's goin on theree.

Pretty sure my TPS is dead and this is causing the car to not trigger the air pump.

I warmed the car up to operating temp, bout 10 minutes of running.

Voltage on the G/R wire was .50 at rest (slightly out of spec)
Voltage on the B/G wire was 4.5 at rest (way out of spec)

Move the throttle and no change in Voltage. So unless I'm doing something wrong I think I'll be needing a new TPS.

Also this makes sense to me because when I warm up the car, if I gave it gas it hesitates for a split second and then revs up. Typical since the car doesn't know when you are pushing on the gas pedal.

You would think the TPS malfunctioning would set a check engine light?

yes it would. Check out http://robrobinette.com/tps_adj.htm before you replace the TPS... its ~$150 from Ray IIRC. You may want to pull codes first, 12 and 18 are for the TPS. Also if it were the TPS odds are high it would cause a goofy idle, hunting, surging, and a lot of backfiring. In any case, best of luck.

It pretty much does all of that with the idle. The reason I know what the voltages are is because I was planning to adjust it. If the voltages do not change there is absolutely no point in adjusting it.

However I have no check engine light, unless it is conveniently unplugged.

Pulled the TPS off, appears it was improperly installed but actually does function. I turned it with my hand while the Key was on and the voltage changes. The trick will be getting it installed properly.

It's pretty easy to install the TPS incorrectly... not very easy to describe how the little plastic feet on the sensor need to line up with the metal tab that rotates when you move the throttle.

This thread might have some more info.
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/tps-adjustment-check-engine-light-help-777317/

For the record I just got this car and the TPS was NOT installed by me previously.

But this time I got it installed and adjusted properly. Which is good news because now my air pump kicks on when it is supposed to. YAY!

But it sounds like a f!@#$!@$#! Harley. It does suck but it appears that after every suction there is a back pressure that blows back out the inlet.

I will be posting a Video momentarily.

Took off the outlet pipe of the air pump and ran the car. Much quieter suction on the front pressure on the back side. I then proceeded to place my thumb over the outlet, and the pump got louder the more of the outlet I plugged up. Basically once there started getting "back pressure" it got louder and the pressure starts to push back out the inlet pipe. So now I'm thinking this may have something to do with the ACV. *sigh* I really hate taking off the UIM.

yea, just sounds like the air isn't moving anywhere in the ACV circuits, it should be getting dumped into either the LIM or split air pipe which wouldn't give it much restriction at any given time.

Thanks Ben, I will see what I can do with the ACV. UGH! Really didn't want to take off the UIM

it's not too bad if you have some small clamps to pinch off the coolant hoses to the throttle body. i hear ya though, the connections behind the UIM are a bastard and always cut up my hands.. just be sure to look everything over thoroughly before putting it back together, pull off the pipes from the ACV to smog pump and be sure no crap is in the tubes, etc. some of the shit on that car came from god knows where and has who knows what inside it. i think about 5 FDs donated parts to that car.

oh yea, forgot about the coolant lines. Thanks for reminding me. :-(

My guess is since the split air pipe was completely missing that whoever owned it before and removed the emissions stuff somehow disabled the ACV, if that's possible. Even though I'm pretty sure all the connectors to it are plugged in.

most of that stuff was simply missing as the car came from an eastern state with no emissions laws so some of it was pieced back together yet failing to install the rest of the smog components, i don't recall anything modified to be blocked but it's been so long i can't remember everything associated with it, i'm sure anything will surface by removing the ACV and blowing compressed air into the various ports.

Yea, I asked Zach if they know if anything was done with the ACV and he said he doesn't know.

Oh well, guess if you want it done right ya gotta do it yourself! And of course get advice from You haha

lol

Basically the solenoids receive power from the main relay and the ecu grounds them to activate as far as I can tell. So to test them I could supply power and ground to see if they switch. I'm going to have to buy a vacuum pump, I've needed one forever lol

FSM test:

Thanks Mahjik :-)

Well got the UIM off tonight, pretty sure my Port air bypass solenoid was unplugged, but I'm not 100% sure. It was stuck underneath the ACV, but I'm pretty sure I wouldn't have been able to get it out had it actually been connected. I pulled the ACV off anyway to have a look at things. Tested all the solenoid valves for resistance all were just around 29 ohms (spec is 27-32 at 68F)
https://www.rx7club.com/attachment.p...1&d=1283232591
Bought myself a miti vac and checked the air valves in the ACV, both actuated with 15 inHg of vaccum. I heard them open and close with what seemed to be no resistance and could also feel it shut when vacuum was released.

Besides the connector I don't think was connected I also discovered one of the vacuum lines for one the secondary switching valve had a hole in it. I think there is a possibility I did it though when I took the ACV out as it is a tight squeeze to get in and out.
https://www.rx7club.com/attachment.p...1&d=1283232591

Also this little flapper valve seems to be a bit rusty, though I'm not sure it matters. I did try to clean it a bit.

http://sphotos.ak.fbcdn.net/hphotos-..._7735319_n.jpg
http://www.facebook.com/photo.php?pi...1&id=719774528

So I guess my next question is, do you think that if that one connector I think was unplugged would cause the ACV to not function at all? The ECU wouldn't activate any of it because it saw that part of it wasn't working?

Are there any other tests I should do while I have all this stuff apart? If nothing further, I'm going to fix the vacuum line make sure everything is connected and give it a shot.

I had the exact same problem. The hose that goes to MAP sensors was knocked off, hose back on and it worked again.

did you check the a/c fuse under the hood near the front of the car....it powers the airpump too thats what my problem was when i was trying to get mine working
if you just got this car I bet you the fuse is removed

I sold this car a while back. Thanks for the tips though.

lol wortex diggin up old threads FFS

So? No one else can ever again have the same problem? and i didnt see a post where someone says problem solved... I just tought i would try to help fellows with the same problem but it seem that isnt the case in this forum or is it? Or is it better that there is like 10 threads with the same problem? If no one uses the search and old threads these forums will be flooded with new threads.

Im just rassin ya. atleast you search lol

Umm, after I Pulled off the ACV and cleaned it and fixed the vacuum lines I put everything back together. It seemed to be a little better, I determined that it was pumping correctly just that the air pump had poor seals and so the air was escaping back out the intake and was excessively noisy.