Erratic idling

[bigalpha]

I'll need to take a much closer look at it, then. Obviously I missed something crucial.

Do you have a diagram or picture of RENIX vacuum routing?

 

[Ecomike]

There are some threads here with the diagram but you will need to search for them. Haynes book has them as well as the FSM. Best to start at the intake manifold and follow all the connections.

 

[bigalpha]

The big problem is that the vacuum hoses are not original ... the PO replaced some of them with and didn't route them according to the original specs.

 

[joe_peters]

Instead of tearing your hair out, why not put it back to factory and work from there:

rockauto.com

DORMAN Part # 46003

{#53004838}
Vacuum Harness; Front

$16.92$0.00$16.92

DORMAN Part # 46004

{#53004868}
Vacuum Harness; Rear* Non-stock item--shipping delayed up to 2 business days

$17.44$0.00$17.44

 

[bigalpha]

Can someone shoot me some pics of their vacuum routing? I hesitate to buy the complete unit for two reasons: 1) I'm so broke and 2) I still have some of the factory hoses.

I did figure out the blinker problem; the small grounding tab that is inside the bulb housing was completely rusted out. I just need to install a new bulb socket and we'll be good.

 

[joe_peters]

Can someone shoot me some pics of their vacuum routing? I hesitate to buy the complete unit for two reasons: 1) I'm so broke and 2) I still have some of the factory hoses.

I did figure out the blinker problem; the small grounding tab that is inside the bulb housing was completely rusted out. I just need to install a new bulb socket and we'll be good.

I'll take some pics and see if I can figure out how to post them here tomorrow.

 

[bigalpha]

Thanks, I really appreciate it. If you have problems posting them you can email them and I'll post them.

 

[bigalpha]

Here's a few pics from my junk; click for super high res goodness:

 

[hobbsar]

One thing you might check is the throttlr cable. Mine sometimes comes apart right where it attaches to the throttle bracket and it will idle very high when it does.
I have been simply snapping it back together, but I really should replace the thing.

 

[Ecomike]

You have a huge vacuum leak on the front of the valve cover, big hose in front of the oil fill cap!!!

 

[bigalpha]

The CCV intake hose? It didn't always look like that.

I didn't realize that that grommet would contribute to the vacuum leak problem.

 

[Ecomike]

The CCV intake hose? It didn't always look like that.

I didn't realize that that grommet would contribute to the vacuum leak problem.

Yep! May not be the major problem, but it does affect the vacuum levels. You also have a missing vacuum line on the back of the air filter housing. Either needs to be connected to the front damper door on the warm up air duct valve in front of the air filter housing, or capped off at the rear of the air filter housing.

Can you get me a picture of the vacuum line where it attaches to the intake manifold? Something about that vacuum line going from the fuel pressure regulator to the intake manifold looks wrong. Also need a better view of the back half of the valve cover and its vacuum line. It should have 0.7 mm (IIRC) metering orifice in that line!

 

[bigalpha]

Yes, I can get you the pictures of the back half of the VC. I just replaced that rear grommet and the hard line with a MOPAR part, since the old one was completely plugged and I had severe blow by.

I can get you a better pic of the intake manifold, too, with the FPR and lines. Gotta wait for the rain to clear up a bit then I'll grab 'em.

 

[bigalpha]

Alright, here's some pics:

 

[Ecomike]

OK, I see what they did now. Looks OK, good to go.

Just make sure there is about a 0.7 mm orifice restriction in that run from the rear valve cover to the intake manifold. Otherwise it will draw to much air and cause a high idle.

 

[Ecomike]

The other vacuum lines run across the rear firewall, to the front battery area (1/2" black poly tube IIRC), under the battery and into a bottle hidden in the front bumper, passenger side. Also a check valve and small lines run into the passenger area through the firewall to the AC controls, damper valve controls. Then you also have the brake booster and it's check valve to worry about.
Also you have a vacuum line to the heater valve, and the MAP sensor. The MAP sensor line runs from the bottom side of the throttle body. If it leaks at all, it can cause very bad running behavior, back fire, choke puke...

 

[bigalpha]

The AC controls work fine with no problems; as does the AC.
I have not checked the hidden bottle in the bumper, but I will.
The vacuum line to the heater valve has a very tight seal and is in good condition.
The lines for the MAP sensor also have tight seal. Other than the idle, the engine runs fine.
There is one line that runs from the booster to the intake and it also fits tight and is in good condition.

At this point, it looks like the most likely culprit is going to the be manifold gasket. Suppose this is the time to go in depth on it, now. If I don't have a propane/MAPP torch, can I use something else?

 

[Ecomike]

The AC controls work fine with no problems; as does the AC.
I have not checked the hidden bottle in the bumper, but I will.
The vacuum line to the heater valve has a very tight seal and is in good condition.
The lines for the MAP sensor also have tight seal. Other than the idle, the engine runs fine.
There is one line that runs from the booster to the intake and it also fits tight and is in good condition.

At this point, it looks like the most likely culprit is going to the be manifold gasket. Suppose this is the time to go in depth on it, now. If I don't have a propane/MAPP torch, can I use something else?

I have never used it so I am not an expert, but I think starter fluid, ether, has been used, but what ever you use be very careful as they are flammable.:flame:

 

[bigalpha]

Hmmm, what about WD40?

 

[ehall]

You want gas not fluid... fluid will pool up and ignite... bye-bye jeep