Vacuum Lines and CUT Smog Components

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MReno
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Vacuum Lines and CUT Smog Components

Post by MReno » Wed Jul 03, 2019 11:03 am

So I now have my '89 (new to me) Grand Wagoneer running (wanted to be sure it had good oil pressure before letting her run for an extended period of time) now, but still up on floor jacks. It looks like much of the SMOG components have been removed, lines cut/plugged or other, but it seems to run ok, other than probably needing a good carb cleaning and tune.

Since it is 25+ years old, Maryland does not conduct emission test, so not having the SMOG components operable is not an issue. However, I am unclear between the relationship with vacuum systems and SMOG systems?

I want to be sure all of the non SMOG systems that require operable vacuum lines are connected properly and that the vacuum system is actually functioning properly.

Is there a suggestion as to where to begin to diagnose, repair, or abandon these systems?
1989 Jeep Grand Wagoneer
Newbee to owing an old classic that needs some work, but she runs!

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Chubbinius
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Re: Vacuum Lines and CUT Smog Components

Post by Chubbinius » Wed Jul 03, 2019 12:55 pm

You might be able to find the information on the vacuum lines and routing in the 89 TSM on the oljeep.com site. Link to the 89 manual is here
http://oljeep.com/89FSM/89Jeep_FullServiceManual.pdf
Hope that helps!
1970 1414X Wagoneer "The Pig"
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weeegoneeer
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Re: Vacuum Lines and CUT Smog Components

Post by weeegoneeer » Sun Jul 07, 2019 5:42 pm

I have vac routing simplified a bit (and still pass emissions). Routing is for a Holley SA 670 & no-EGR Performer intake, but the spirit is there to follow. Also, I've curved my distributor to work on manifold vacuum.

Sounds like you may have a stock-ish system so by getting rid of the the coolant temperature override switches and such you may have some cold drivability issues, but where I'm at has served me well. Sometimes when it was really cold I had to sit for 5 minutes before going anywhere — Wisconsin 5 degree cold. Am in Oregon now and doesn't get that cold, just sit for a minute until my engine sounds warmish.

Here's a diagram:

Image
1984 GW


Topic author
MReno
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Re: Vacuum Lines and CUT Smog Components

Post by MReno » Mon Jul 08, 2019 6:52 am

Thanks weeegoneeer.
1989 Jeep Grand Wagoneer
Newbee to owing an old classic that needs some work, but she runs!

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tgreese
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Re: Vacuum Lines and CUT Smog Components

Post by tgreese » Tue Jul 09, 2019 6:38 am

I would definitely keep vapor recovery. That's not shown on the above diagram. I'd also keep the TAC (thermostatic air cleaner). Not all of these vacuum-powered devices affect tailpipe emissions directly, and they have a practical value on their own. Do you own the TSM (factory service manual) for your year Jeep? You will gain a lot of insight by reading the emissions section while following along beside your Jeep. These devices change from year to year, as technology improves and the emissions requirements evolve. You need the factory publication - the Haynes or Chiltons book won't help you.
http://www.bjsoffroad.com/1989-Jeep-Fac ... _1059.html - sometimes these are available at RockAuto on CD-ROM.

I do not have a 1989 TSM, but they follow a standard format. At the end of the emissions chapter there is a table that says which devices were used with your model and equipment. Then look back at the text for each device and compare to your Jeep and the vacuum diagram. Much of the complexity comes from using the engine vacuum to change the EGR characteristics depending on vacuum. So the vacuum becomes both a signal and a power source. Things get a lot simpler when you go to electronic fuel injection (EFI), which then uses vacuum only as a signal. The computer can easily combine signals to control the devices - including the fuel input.

Conversion to EFI would clean things up a lot, but you would not want to eliminate those devices that have added practical value, like PCV, TAC and vapor recovery. Also note that your carburetor requires an external connection to the manifold vacuum, just for normal operation. Read the section about the carburetor power circuit.

Ok, see the link above in Chubinius' post for the '89 TSM. There is an emissions chapter, but it does not have a table per se. Instead I would look at the vacuum diagram and look up each of the devices. They may be in the emissions chapter, exhaust, or fuel.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 FCA Jeep Cherokee KL Trailhawk, ECO Green


rocklaurence
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Re: Vacuum Lines and CUT Smog Components

Post by rocklaurence » Tue Jul 09, 2019 7:10 am

If your not required to pass emisions, Id bypass and plug everything. These vehicles were a mess because the Engineers didnt invest the money for EFI but instead tried vacuum/switches/bandaids to get a carb to pass emissions. If you keep the emissions in place, you will constantly be chasing leaks and failures. IMO. Also, switch to an HEI ignition to get rid of the OEM spark module


Topic author
MReno
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Re: Vacuum Lines and CUT Smog Components

Post by MReno » Wed Jul 10, 2019 11:14 am

Thanks tgreese and rocklaurence for your replies. I only have the Haynes manual, so I will have to try and acquire the TSM service manual. I know there is a Super Coil that was installed, but not sure if spark module was upgraded to an HEI as well. I'm not an serious engine guy, so I am having to learn the language as well as my way around what I have on the vehicle.
1989 Jeep Grand Wagoneer
Newbee to owing an old classic that needs some work, but she runs!


weeegoneeer
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Re: Vacuum Lines and CUT Smog Components

Post by weeegoneeer » Wed Jul 10, 2019 8:19 pm

You can grab the full service manual here: http://oljeep.com/edge_parts_man.html

Download the 1989 manual and vacuum routing for your motor is on page 25-7, you can go from there if you want to restore everything back.

SO glad that site exists.
1984 GW


candymancan
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Re: Vacuum Lines and CUT Smog Components

Post by candymancan » Thu Jul 11, 2019 2:57 am

Im in Virginia.. same thing 25 yesrs no emissions cept needing a cat but thats federal.

I removed the stock air hat because it right there has like 20 vacuum lines and switchs on it. I never once missed the TAC this passed winter jeep ran fine without it.. I just use an old fashioned open air cleaner.. Itll act just like a TAC sucking hot engine bay air. With 145 awsome Zhpz this engine will see no benefit from the (cold ra.) air intake anyway.. so i opted for a cleaner look

. I took all the lines on the egr snd blocked em with screws. Then i removed the air pump and metal tube going to the cat.. i plugged the cat hole... some pipe plugs and siliconed em in the manifold tubes. I kept the charcoal canister though.. I have like 4 or 5 vacuum lines thats it.. the cabister has 3. And i kept thr one going to the distributor.. and of course thr ones to the transfercase. And the PCV on thr back of the carb. The oil filler tube i just put a breather filter on it.

Very simple
2013 SS camaro, cammed, and modded too much to say 500 RWHP/650 crank 40k
1998 Jeep Grand Cherokee 5.9L Limited 195k
1998 Jeep Grand Cherokee 4.0 I6 laredo 274k
1990 Jeep Grand Wagoneer 132k

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tgreese
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Re: Vacuum Lines and CUT Smog Components

Post by tgreese » Thu Jul 11, 2019 7:37 am

I would expect the cat to plug up eventually if you don't send air to it. The earlier cats depend on that flow of fresh air to "burn" the excess emissions.
Tim Reese
Maine beekeeper's truck: '77 J10 LWB, 258/T15/D20/3.54 bone stock, low options (delete radio), PS/PDB, hubcaps.
Browless and proud: '82 J20 360/T18/NP208/3.73, Destination A/Ts, 7600 GVWR
Copper Polly: '75 CJ-6, 304/T15, PS, BFG KM2s, soft top
GTI without the badges: '95 VW Golf Sport 2000cc 2D
Dual Everything: '15 FCA Jeep Cherokee KL Trailhawk, ECO Green

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HowardT64
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Re: Vacuum Lines and CUT Smog Components

Post by HowardT64 » Thu Jul 11, 2019 1:51 pm

I am running with NO Idle solenoid and all of my emissions crap is gone. I did have to tweak the timing a bit....but the Jeep runs fine without all of that nonsense. The wire that runs to the choke does attach as well to the idle control solenoid.
1990 Grand Wagoneer
Duck Blind 2
360 V8
A/C P/S P/B P/W
Solar Equipped
55 watt Burner Fog Lights


candymancan
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Re: Vacuum Lines and CUT Smog Components

Post by candymancan » Thu Jul 11, 2019 2:15 pm

tgreese wrote:I would expect the cat to plug up eventually if you don't send air to it. The earlier cats depend on that flow of fresh air to "burn" the excess emissions.

Its a brand new magnaflow cat. It just has the air line on it for air pumps. It wont clog up im betting since its a brand new cat
2013 SS camaro, cammed, and modded too much to say 500 RWHP/650 crank 40k
1998 Jeep Grand Cherokee 5.9L Limited 195k
1998 Jeep Grand Cherokee 4.0 I6 laredo 274k
1990 Jeep Grand Wagoneer 132k


Topic author
MReno
Posts: 46
Joined: Sun Mar 03, 2019 6:39 pm

Re: Vacuum Lines and CUT Smog Components

Post by MReno » Fri Jul 12, 2019 10:07 am

Candymancan,
Sounds like the setup you have is what I want. I'll try and begin to trace what is cut/capped and removed. I know the air pump is gone for sure and several hoses have screws in them, just not sure what they run to/from. Thanks for the help.
1989 Jeep Grand Wagoneer
Newbee to owing an old classic that needs some work, but she runs!

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