Removing smog pump on an 87. Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

UATahoe · 02-19-2013, 10:46 AM

I am getting ready to install a new motor in the 87 and i am in the process of pulling the stock 350. The smog pump on the truck is run by its own pulley. Nothing else runs off of it. So i am guessing that once i remove the pump i can just do away with that pulley right? The pump is the lower accessory on the left. What about all of the electrical connections? Thanks for the help!

Jonboy · 02-19-2013, 11:28 AM

Yes you can. Just tuck the connectors back to the harness sheath and you are good to go.

UATahoe · 02-19-2013, 11:41 AM

Thanks Jonboy. Where do those connectors run to? When i pul the motor do i need to trace them down and unplug? I am guessing they run to the computer and up on top of the block maybe?

guitarfreak235 · 02-19-2013, 11:53 AM

Quote:

Originally Posted by UATahoe

I am getting ready to install a new motor in the 87 and i am in the process of pulling the stock 350. The smog pump on the truck is run by its own pulley. Nothing else runs off of it. So i am guessing that once i remove the pump i can just do away with that pulley right? The pump is the lower accessory on the left. What about all of the electrical connections? Thanks for the help!

well the pulley on the smog pump comes off with it, the main pulley is one piece so idk what pulley you plan on removing. unless you replace the main pulley with another one. i removed my smog stuff and its pretty straight forward

UATahoe · 02-19-2013, 11:56 AM

You are right. Bad choice of words there. Really just meant that once i pull the smog pump off, i can ditch the belt and go on. I just wanted to make sure before i did it. It seems like a no brainer but normally those are hte ones that usually screw me. LOL

Jonboy · 02-19-2013, 01:20 PM

Quote:

Originally Posted by UATahoe

Thanks Jonboy. Where do those connectors run to? When i pul the motor do i need to trace them down and unplug? I am guessing they run to the computer and up on top of the block maybe?

I am not sure where the wires ultimately plug into the harness to eliminate them totally. I would maybe tape them up and hide them in the loom, just in case you ever have to have the smog pump back on. You will have to get a chip burned to make your 383 happy anyhow, just have the emissions deleted at that time. You could also have the EGR gone at that time as well.

UATahoe · 02-19-2013, 02:21 PM

Roger that. I have Harris performance on the check sheet to take care of the computer chip part. I will make sure all of that is scratched so there wont be any check engine light problems. Next thing to do is tackle all of the wiring on top of the block to see what needs to be unhooked.

bigd65 · 02-19-2013, 08:23 PM

Is there a gain, to removing the EGR on an 87. I know there isn't on the older ones
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beamn7 · 02-19-2013, 10:45 PM

PM me if you want to sell the smog pump and diverter valve. We still need that stuff out here in good 'ol California........sheesh...

bigd65 · 02-20-2013, 09:30 AM

I think I threw mine away. I would have given it to you for shipping...I dont get my truck inspected. I have ANTIQUE plates on it and only register it every 5 years. Its not a daily driver. The law allows for periodic driving and test driving...but this IS TEXAS

Jonboy · 02-20-2013, 12:13 PM

Quote:

Originally Posted by bigd65

Is there a gain, to removing the EGR on an 87. I know there isn't on the older ones
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When I did the TBI swap on my '74, the harness I used deleted all of the emissions. I blocked it off for that reason. If the OP is doing a 383, I would imagine the original intake is going to go away anyhow. Not having an EGR would clean up the EGR, request solenoid, tubing, and wiring. That would also open up a lot more intake choices (with the use of a carb to TBI adapter- the aftermarket TBI intakes are a little pricy...). As far as a performance gain, it is probably negligable.

UATahoe · 02-20-2013, 12:30 PM

Exactly right. New intake manifold for me. Anybody have pictures of all the egr stuff that can be removed?
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Jonboy · 02-20-2013, 02:59 PM

Follow the vacuum line from the EGR, and you will come to the switching solenoid (should be on the right side of the TB). Those can come off, and the associated ose and tubes. plug the port on the TB with a vacuum cap, and done.

UATahoe · 02-20-2013, 03:12 PM

So which line do I follow? Lol

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Jonboy · 02-20-2013, 07:53 PM

The one from the EGR. The two boxes you have pics of are the knock sensor module (5 pin plug), and the MAP sensor (3 pin green plug). You need both of those. The EGR valve is behind the TB; the request solenoid should have a 2 pin plug and 2 vac lines (1 in, 1 out).

UATahoe · 02-20-2013, 08:37 PM

Awesome. Thanks again for all of the help! Should I unplug the blocks pictured and then unbolt from the intake or just unplug from the tbi and unbolt when I pull the motor?
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bigd65 · 02-20-2013, 10:07 PM

I was always told that EGR actually cools the cylinders and prevents ALOT of detonation. If you remove that, the timing, through the knock sensor will retard the timing ALOT and thus lose performance.
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UATahoe · 02-21-2013, 08:37 PM

Another round of can it stay or go. What is this metal tube for?
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UATahoe · 02-21-2013, 08:42 PM

Jonboy, were these the pieces you said could be removed?
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02-19-2013, 10:46 AM	#1
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Removing smog pump on an 87. Question I am getting ready to install a new motor in the 87 and i am in the process of pulling the stock 350. The smog pump on the truck is run by its own pulley. Nothing else runs off of it. So i am guessing that once i remove the pump i can just do away with that pulley right? The pump is the lower accessory on the left. What about all of the electrical connections? Thanks for the help! Attached Images

02-19-2013, 11:28 AM	#2
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Removing smog pump on an 87. Question Yes you can. Just tuck the connectors back to the harness sheath and you are good to go.

02-19-2013, 11:41 AM	#3
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Thanks Jonboy. Where do those connectors run to? When i pul the motor do i need to trace them down and unplug? I am guessing they run to the computer and up on top of the block maybe?

02-19-2013, 11:56 AM	#5
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question You are right. Bad choice of words there. Really just meant that once i pull the smog pump off, i can ditch the belt and go on. I just wanted to make sure before i did it. It seems like a no brainer but normally those are hte ones that usually screw me. LOL

02-19-2013, 02:21 PM	#7
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Roger that. I have Harris performance on the check sheet to take care of the computer chip part. I will make sure all of that is scratched so there wont be any check engine light problems. Next thing to do is tackle all of the wiring on top of the block to see what needs to be unhooked.

02-19-2013, 08:23 PM	#8
bigd65 Registered User Join Date: Mar 2000 Location: Clute, TX. Posts: 1,935	Re: Removing smog pump on an 87. Question Is there a gain, to removing the EGR on an 87. I know there isn't on the older ones Posted via Mobile Device __________________ 2004 Silverado Crewcab 1972 Chevy Monte Carlo 2017 Chevy Tahoe

02-19-2013, 10:45 PM	#9
beamn7 Registered User Join Date: Oct 2011 Location: Wildomar, CA Posts: 466	Re: Removing smog pump on an 87. Question PM me if you want to sell the smog pump and diverter valve. We still need that stuff out here in good 'ol California........sheesh...

02-20-2013, 09:30 AM	#10
bigd65 Registered User Join Date: Mar 2000 Location: Clute, TX. Posts: 1,935	Re: Removing smog pump on an 87. Question I think I threw mine away. I would have given it to you for shipping...I dont get my truck inspected. I have ANTIQUE plates on it and only register it every 5 years. Its not a daily driver. The law allows for periodic driving and test driving...but this IS TEXAS __________________ 2004 Silverado Crewcab 1972 Chevy Monte Carlo 2017 Chevy Tahoe

02-20-2013, 12:30 PM	#12
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Exactly right. New intake manifold for me. Anybody have pictures of all the egr stuff that can be removed? Posted via Mobile Device

02-20-2013, 02:59 PM	#13
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Removing smog pump on an 87. Question Follow the vacuum line from the EGR, and you will come to the switching solenoid (should be on the right side of the TB). Those can come off, and the associated ose and tubes. plug the port on the TB with a vacuum cap, and done.

02-20-2013, 03:12 PM	#14
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question So which line do I follow? Lol Posted via Mobile Device Posted via Mobile Device Attached Images

02-20-2013, 07:53 PM	#15
Jonboy Slots go on anything! Join Date: May 2003 Location: Richardson, TX Posts: 5,957	Re: Removing smog pump on an 87. Question The one from the EGR. The two boxes you have pics of are the knock sensor module (5 pin plug), and the MAP sensor (3 pin green plug). You need both of those. The EGR valve is behind the TB; the request solenoid should have a 2 pin plug and 2 vac lines (1 in, 1 out).

02-20-2013, 08:37 PM	#16
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Awesome. Thanks again for all of the help! Should I unplug the blocks pictured and then unbolt from the intake or just unplug from the tbi and unbolt when I pull the motor? Posted via Mobile Device Last edited by UATahoe; 02-21-2013 at 12:22 AM.

02-20-2013, 10:07 PM	#17
bigd65 Registered User Join Date: Mar 2000 Location: Clute, TX. Posts: 1,935	Re: Removing smog pump on an 87. Question I was always told that EGR actually cools the cylinders and prevents ALOT of detonation. If you remove that, the timing, through the knock sensor will retard the timing ALOT and thus lose performance. Posted via Mobile Device __________________ 2004 Silverado Crewcab 1972 Chevy Monte Carlo 2017 Chevy Tahoe

02-21-2013, 08:37 PM	#18
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Another round of can it stay or go. What is this metal tube for? Posted via Mobile Device Posted via Mobile Device Attached Images



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02-21-2013, 08:42 PM	#19
UATahoe Registered User Join Date: Mar 2012 Location: Huntsville, AL Posts: 1,000	Re: Removing smog pump on an 87. Question Jonboy, were these the pieces you said could be removed? Posted via Mobile Device Posted via Mobile Device Posted via Mobile Device Attached Images

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