Vacuum Lines

[hitman72]

So I have a 88 4.0l with the EGR system. I was wondering if there was a diagram of what lines can be removed and capped. I am just wondering cause i have lines that are broken so they must not work haha. Could i even go as far as removing the whole system, problems with smog or it running right?

[cruiser54]

Don't do it. The idle will be screwed up etc. Just put new lines on it.

 

Renix Vacuum Harnesses

The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367

http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1367%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1367%26Dk%3d1%26Dp%3d3%26N%3d0

The vacuum harness that is closest to the air cleaner, EGR etc, and is called the rear harness, is Napa part number BK-715-1366.

http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1366%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1366%26Dk%3d1%26Dp%3d3%26N%3d0

The tube from the rear of the valve cover to the intake manifold is part number 715-1365.

http://www.napaonline.com/Catalog/Result.aspx?Ntt%3d715-1365%26Ntk%3dKeyword%26Nty%3d1%26Dn%3d0%26D%3d715-1365%26Dk%3d1%26Dp%3d3%26N%3d0

Revised 09-11-2012

[hitman72]

what about other non EGR related lines.

 

Thanks for the part numbers.

[cruiser54]

what about other non EGR related lines.

 

Thanks for the part numbers.

 

Those are not eGR lines. the eGR valve is located on the driver's side of the intake manifold.

[hitman72]

Sorry for the confusion, are the lines you listed able to be removed or should they be checked and replaced if needed?

 

thanks

[cruiser54]

Replaced. Get them all and be done with it. If you want that Jeep to run well and serve you well, check out the REnix tips link in my signature.

[fiatslug87]

Keep all your vac lines intact especially since you live in CA and have to Smog test every two years. A visual inspection is part of it.

[cruiser54]

Keep all your vac lines intact especially since you live in CA and have to Smog test every two years. A visual inspection is part of it.

Now that's a hell of a good suggestion.

[hitman72]

haha ya, good old CA. I just like messing with things that are not broken i guess lol.

[cruiser54]

Good ole Commifornia. Left there 35 years ago. No regrets.

[ftpiercecracker1]

Cruiser, are you saying that if you delete the EGR the motor will not run right? I ask because i just finished cutting out my EGR entirely, wiring and all. Reason being, i am swapping in a 93 engine with a 99 intake and therefore there is no place for the EGR. I have also read several threads on deleting the EGR and those who have done it have not reported any adverse effects, but when i saw you had said something about the idle being wack, i got the cold sweats. If you could clarify that would be great.

 

ftpiercecracker

 

 

sorry for the thread jack OP

[hitman72]

no need to be sorry at all. I am very interested in the response, that way I won't be the one with the cold sweats (I almost started to remove that stuff a few weeks ago).

[cruiser54]

Cruiser, are you saying that if you delete the EGR the motor will not run right? I ask because i just finished cutting out my EGR entirely, wiring and all. Reason being, i am swapping in a 93 engine with a 99 intake and therefore there is no place for the EGR. I have also read several threads on deleting the EGR and those who have done it have not reported any adverse effects, but when i saw you had said something about the idle being wack, i got the cold sweats. If you could clarify that would be great.

 

ftpiercecracker

 

 

sorry for the thread jack OP

I am not saying that. I was thinking the OP was confused as to what was eGR and what was CCV type lines.

[ParadiseMJ]

The vacuum lines are there...for a reason. 

 

What reason?  I dunno.  But they ARE there.  They're not there for any shade tree mechanic to start ripping them out and capping them. If you are having issues, not passing smog, your heater or cruise control doesn't work or your idle is way high/low...ripping out vac lines is NOT going to help.

 

As fiatslug points out, you live in CA.  Not only will you not pass the visual inspection, you'll fail on the sniffer as well.  Screwed up (by the owner) vac systems is one of the main reasons you'll flunk a CA smog test.  Patching vac lines with duct tape, glue, galvanized pipe and sprinkler line is stupid.  Buy the right parts, keep them in good shape, replace worn, cracked, rubbed, broken or corroded lines with new lines...you'll be glad you did.

 

Side note:  I moved out of what everyone "back there" calls California (AKA everybody lives at the beach, LA, Disneyland, Hollywood and moved to NORTHERN California. 

 

[hitman72]

Got it, don't remove them. Now i just have to find the one that is leaking. When the engine is cold it has a surge (up and down) idle. Once the engine is up to temp it goes away. This does hint to me that it may be not be a hose but something that is attached to the block and goes away as the metal expands.

[cruiser54]

Like the intake manifold bolts...............

[mjeff87]

_{I don't want to tip the apple cart here, and I certainly don't recommend you remove any smog equipment if you have to pass a visual inspection, but I ditched all the vacuum crap on mine (well, almost all of it).  The only vac lines I'm running are for the MAP, vac canister (relocated), fuel pressure regulator, brake booster and CCV.  It runs fine....}

 

_Jeff

 

_{Image Not Found}

[hitman72]

_{I don't want to tip the apple cart here, and I certainly don't recommend you remove any smog equipment if you have to pass a visual inspection, but I ditched all the vacuum crap on mine (well, almost all of it).  The only vac lines I'm running are for the MAP, vac canister (relocated), fuel pressure regulator, brake booster and CCV.  It runs fine....}

 

_Jeff

 

_{Image Not Found}

did yours start out with an eGR system, don't see one on there now but can tell.

[mjeff87]

Yes, it's an 87....all EGR is deleted.

[jeepdoggydogB]

Keep all your vac lines intact especially since you live in CA and have to Smog test every two years. A visual inspection is part of it.

@Hitman72,

Listen to Mike the emissions folks here will not tolerate removing any vacuum hose that affects smog E.G. idle, fuel mixture and so forth. I am up for a smog in August of this year and have no idea how much more stringent the new Star stations will be. Some are saying by design they want to fail older vehicles as they remove the old caps on what you have to spend on your vehicle to make it compliant (the old referee stations).

[jeepdoggydogB]

That's older vehicles to fail  :fs1:

[hitman72]

@Hitman72,

Listen to Mike the emissions folks here will not tolerate removing any vacuum hose that affects smog E.G. idle, fuel mixture and so forth. I am up for a smog in August of this year and have no idea how much more stringent the new Star stations will be. Some are saying by design they want to fail older vehicles as they remove the old caps on what you have to spend on your vehicle to make it compliant (the old referee stations).

haha its Vallejo, I am sure for $50 you could get anything done in that town ;)

 

thanks for the info tho, i have heard a few stories if guys (not MJ related) getting salvage titles cause of bad smog.

[jpdriver1]

I'm currently battling with a NO level of 1950 ppm -- two yr old cat, new O2 sensor, egr vac lines cleaned/replaced ---- help (maybe even the name of a guy wink wink)

[ParadiseMJ]

what is NO?  I'm looking at my smog report and all it has is CO2, HC and CO.  I passed with flying colors, zero% CO, 14.5 CO2, 20 HC.  Visual was dead on. No one but me has touched this truck, and I'm an amateur.  I'm pretty sure not screwing with the emissions system and so-so maintenance is the cause of most older car smog fails.

[fiatslug87]

High nitrogen oxide is caused by high combustion temperatures, a faulty EGR valve can cause it. Check the operation of the EGR system.

 

 

 

 

Some more tips http://m.smogtips.com/failed-high-NO-nitric-oxide.cfm