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midpipe w/airpump?

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Old Feb 25, 2003 | 09:04 PM
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From: Houston
midpipe w/airpump?

Is it possible to use a midpipe while using the stock airpump?

Thanks
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Old Feb 25, 2003 | 09:11 PM
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yes, but there is no point to it.
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Old Feb 25, 2003 | 10:07 PM
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From: nj, McGuire AFB
just unplug the airpump so that it isnt using any power off the engine. then buy the greddy pulley kit and remove it
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Old Feb 25, 2003 | 10:08 PM
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From: Houston
Originally posted by evot23
yes, but there is no point to it.
Why is there no point?
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Old Feb 25, 2003 | 10:21 PM
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Originally posted by Rx7pimpin
Why is there no point?
you're getting rid of your cat...the cat needs the air pump to work and reduce emissions. with a midpipe there's no need for the air pump.
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Old Feb 25, 2003 | 10:30 PM
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I think if you unplug it you need to put some kind of resistor in so that the ecu thinks its still there.
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Old Feb 25, 2003 | 10:52 PM
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The essential answer is yes, it can be done. I did that for many years. I just took off the tubing and pipe that goes to the main cat.

There is a point if you intend/need to put back the main-cat for smogging purposes. It's well known that an airpump on the shelf, or not turning will freeze up and be useless.
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Old Feb 25, 2003 | 11:01 PM
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From: nj, McGuire AFB
if you are running a midpipe you should have some kind of ecu upgrade so unpluging the air pump wont hurt anything. it will run
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Old Feb 25, 2003 | 11:17 PM
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get a 4 ribed 30 inch belt and just remove it you dont need the greddy pully kit to do that!

Marc
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Old Feb 26, 2003 | 12:39 AM
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Originally posted by jramosrx7

There is a point if you intend/need to put back the main-cat for smogging purposes. It's well known that an airpump on the shelf, or not turning will freeze up and be useless.
I can vouch for this.
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Old Feb 26, 2003 | 04:50 AM
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Originally posted by Rx7pimpin
Why is there no point?
There is no point bec. there is no cat. If you are going midpipe you are removing the cat.
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Old Feb 26, 2003 | 04:58 AM
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There is a point if you intend/need to put back the main-cat for smogging purposes.
Ah! I forgot about emissions and smog...don't have that in FL
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Old Feb 26, 2003 | 08:15 AM
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From: Jax, Fl.
Guys, on the non-cali model FD's the airpump is controlled through a relay (I'm not familiar enough with cali models). Since the coil of the airpump relay is still in the circuit the ECU doesn't notice any difference in current flow when energized.

This is one of the very few things that can be removed without worring about the ECU having a fit over...
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Old Feb 26, 2003 | 10:33 AM
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Originally posted by es
Guys, on the non-cali model FD's the airpump is controlled through a relay (I'm not familiar enough with cali models). Since the coil of the airpump relay is still in the circuit the ECU doesn't notice any difference in current flow when energized.

This is one of the very few things that can be removed without worring about the ECU having a fit over...
I bought my FD from Florida and removed the airpump. Idle fluctuates badly so I'm guessing the ecu is having a fit with it? Guess I'll have to get a pfc. I have all the bolt on mods.
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Old Feb 26, 2003 | 10:36 AM
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I bought my FD from Florida and removed the airpump. Idle fluctuates badly so I'm guessing the ecu is having a fit with it? Guess I'll have to get a pfc. I have all the bolt on mods.
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Old Feb 26, 2003 | 10:49 AM
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possible, yes...
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Old Feb 26, 2003 | 11:22 AM
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From: Jax, Fl.
Originally posted by RX7 RAGE
I bought my FD from Florida and removed the airpump. Idle fluctuates badly so I'm guessing the ecu is having a fit with it? Guess I'll have to get a pfc. I have all the bolt on mods.
Not necesarily the ECU having a fit with it, but more that the ECU is tuned to idle with that extra air being injected. You probably need to adjust the idle air mixure & possibly the idle RPM until it cleans up. (it's a good idea to install a fresh set of plugs before these adjustments)

The Idle air adjustment screw is on the bottom of the throttle body toward the firewall side. You'll need a mirror to see it. There is even a small notch in the bottom of the Throttle body elbow flange for clear access of this screw.
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Old Feb 26, 2003 | 05:45 PM
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Originally posted by es
Not necesarily the ECU having a fit with it, but more that the ECU is tuned to idle with that extra air being injected. You probably need to adjust the idle air mixure & possibly the idle RPM until it cleans up. (it's a good idea to install a fresh set of plugs before these adjustments)

The Idle air adjustment screw is on the bottom of the throttle body toward the firewall side. You'll need a mirror to see it. There is even a small notch in the bottom of the Throttle body elbow flange for clear access of this screw.
Which way do i turn the screw to make it run leaner at idle? and how much should i turn it? I don't want to run lean at idle and blow my engine..... thanks
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Old Feb 26, 2003 | 07:10 PM
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Originally posted by jramosrx7
There is a point if you intend/need to put back the main-cat for smogging purposes. It's well known that an airpump on the shelf, or not turning will freeze up and be useless.
My air pump squeaks quite a bit, as if a bearing or something of that nature is is damaged. Could that be because of the miles on it (about 57K)? Or is that a reason to suspect that the air pump was off in the past and on a shelf, and a previous owner may have removed mods and restored it back into stock form before a sale? Just curious, I plan to remove the airpump anyways and get a midpipe.
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Old Feb 26, 2003 | 08:09 PM
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wow I cant believe none of you know the air pump supplies secondary air injection at idle and low rpms. Thats why it runs like **** when you just unplug it without an ECU to tune out the extra fuel at idle. If you unplug your airpump you will have to jack up the idle and plan on changing out your fouled plugs every day.
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Old Feb 26, 2003 | 08:34 PM
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wow I cant believe none of you know the air pump supplies secondary air injection at idle and low rpms. Thats why it runs like **** when you just unplug it without an ECU to tune out the extra fuel at idle. If you unplug your airpump you will have to jack up the idle and plan on changing out your fouled plugs every day.
The idle isnt that bad when you unplug it and it isn't bad for everyone (was for me but not for my friend)...and yes, I believe most of us do know that...the secondary air injection at idle is what helps you with the emissions. At higher RPM you get enough flow to get rid of/burn hydrocarbons.

Fouled plugs?...not likely from just removing the airpump. You may have to raise the idle, your plugs will be fine...at least they were in my case.
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Old Feb 26, 2003 | 09:16 PM
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Originally posted by evot23
The idle isnt that bad when you unplug it and it isn't bad for everyone (was for me but not for my friend)...and yes, I believe most of us do know that...the secondary air injection at idle is what helps you with the emissions. At higher RPM you get enough flow to get rid of/burn hydrocarbons.

Fouled plugs?...not likely from just removing the airpump. You may have to raise the idle, your plugs will be fine...at least they were in my case.
Plugs will foul with a rich condition and will be noticed by the "miss" in the idle. The air injection being gone will change the Air Fuel ratio at idle. Raising the idle only tries to mask the problem. I suggest leaving it plugged in until you get an ECU like the Power FC where you can pull out fuel at the 1000k rpm level. This way your not just trying to compensate for a problem you have created. Of course if you think your gaining some power by unplugging it you may be right. Of course your also losing some drivability. Try unpluggin it and then drive the car around town. Plug it back in and adjust the idle back down and drive it again. I think you will notice you have much better low end response and idle. In my experience every FD i have seen has had problems when unplugging the air pump unless of course its been modded to accomidate a missing pump.
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Old Feb 27, 2003 | 08:08 AM
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From: Jax, Fl.
Zoom Zoom, that is why I suggested tuning the idle air mixture screw...

AF908. I think you turn it counter CW. (can't really remember) There is no need to worry about blowing your ingine as this screw only effects the idle air mixture & running lean at idle will just cause the car to run like crap & stall.
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Old Feb 27, 2003 | 08:24 AM
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Idle air screw will not fix this. The mixture is just too rich at idle without the air pump. Leave the air pump on until you get a PFC or something like ZoomZoom said.
-MP
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Old Feb 27, 2003 | 08:29 AM
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Originally posted by es
Zoom Zoom, that is why I suggested tuning the idle air mixture screw...

AF908. I think you turn it counter CW. (can't really remember) There is no need to worry about blowing your ingine as this screw only effects the idle air mixture & running lean at idle will just cause the car to run like crap & stall.
Actually it's CCW. CW will reduce idle air bypass and cause the ecu to drop idle rpm. Do the adjustment only when the car is fully warmed up.
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