My never-ending thread of questions.

[bigalpha]

Undoubtedly, I'll find something else to ask questions about. I appreciate the help; I'm new the the RENIX arena, as my 95 XJ has the 'modern' feel to it. :D

 

Now, for some questions:

Q1. How can you narrow down the cause of an AC issue? Recharge vs. replacing parts

Q2. How do you check the level of coolant in a closed system? I think mine is low.

Q3. There are 2 temp senders, right? One for the gauge; one for the computer?

Q4. Looks like I'm missing some pieces here?:

[bigalpha]

A2. I'm not ready to pull the hoses, because of time constraints. So, I'll add 50/50 coolant to the pressure bottle (when cool) up to the fill line and drive it. Next time I get in it, I'll check coolant levels (when cool, again). Add as necessary. Burp it through the temp sender port. Repeat until full.

[Pete M]

That is indeed how to check the coolant level. :thumbsup:

 

 

For the A/C, I paid a shop to track the leak and change over to R-134. I've never had much luck doing A/C stuff by myself. :(

[Automan2164]

For the A/C.Make sure there is some stuff in the system. Easiest, although not eco-friendly is to use a screw drive to push in the schrader valve on the ac line. Just enough to either get a spray of a/c, or nada. If there is pressure, most likely still good. If thats good, check the compressor to make sure its cycling. Should be coming on and off intermittantly. If thats good, follow the line that leads to the cab. Just before it enters the cab, there should be a crimp where it looks like someone with a pair of pliers gripped the line, and left two flat spots. Feel that area before and after the crimp. That is the fixed orafice tube. Hot/warm referigerant gets forced there, and after a small opening, cools with expansion. If its warm/hot before and cool/frosty after, should be good to go on that end. I will also stress that you make sure your temperature selector blend door is working. We have had a few guys at work that will throw parts and compressors at something only to realize the only problem was the cable going to the blower assy box was broken and wouldn't move from hot to cold.

 

Rob L.

[bigalpha]

That is indeed how to check the coolant level. :thumbsup:

 

 

For the A/C, I paid a shop to track the leak and change over to R-134. I've never had much luck doing A/C stuff by myself. :(

 

I've never messed with A/C stuff, besides changing the temp inside the cab. How much did it cost you for the shop to trace the leak?

[bigalpha]

For the A/C.Make sure there is some stuff in the system. Easiest, although not eco-friendly is to use a screw drive to push in the schrader valve on the ac line. Just enough to either get a spray of a/c, or nada. If there is pressure, most likely still good. If thats good, check the compressor to make sure its cycling. Should be coming on and off intermittantly. If thats good, follow the line that leads to the cab. Just before it enters the cab, there should be a crimp where it looks like someone with a pair of pliers gripped the line, and left two flat spots. Feel that area before and after the crimp. That is the fixed orafice tube. Hot/warm referigerant gets forced there, and after a small opening, cools with expansion. If its warm/hot before and cool/frosty after, should be good to go on that end. I will also stress that you make sure your temperature selector blend door is working. We have had a few guys at work that will throw parts and compressors at something only to realize the only problem was the cable going to the blower assy box was broken and wouldn't move from hot to cold.

 

Rob L.

 

Cool, I'll check all those things. Hopefully, it's just a simple leak. Summer is fast approaching, and I like to stay cool. Not sure if it's related, but my e-fan runs constantly.

[Pete M]

That is indeed how to check the coolant level. :thumbsup:

 

 

For the A/C, I paid a shop to track the leak and change over to R-134. I've never had much luck doing A/C stuff by myself. :(

 

I've never messed with A/C stuff, besides changing the temp inside the cab. How much did it cost you for the shop to trace the leak?

 

 

Don't remember, it was 12 years ago. :dunno: And I had a coupon for the conversion which made it like $5 more than buying the kit. :D

[Wildman]

This link should answer your Q3 -

 

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

 

I don't have a picture of the CCV hoses, but from your picture, your missing something there.

[bigalpha]

This link should answer your Q3 -

 

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

 

I don't have a picture of the CCV hoses, but from your picture, your missing something there.

 

Thanks, I had found that earlier, but didn't have a chance to really read through it.

 

Any idea of the routing of the vacuum hoses? It looks major FUBAR.

[bigalpha]

This link should answer your Q3 -

 

http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm

 

I don't have a picture of the CCV hoses, but from your picture, your missing something there.

 

Alright, I think I got it. The sensor that is the burp point for the coolant is only for the temp gauge in the dash. Is there a way to test it, or is it just a replacement part?

 

The temp sensor thats on the bottom of the block, next to the drain plug, is the one that interfaces with the ECU, etc to insure the correct coolant temp is being sent. Is it a two-wire plug? Seems easy enough to check, I have a DMM. Will I need to backprobe it, or disconnect it completely?

 

I have an infrared thermometer ... where is a good place to check the coolant temperature to see if it verifies with the gauge and the CTS?

[navigator]

 

not to hijack the thread but i just bought a comanche and if you look in this pic there are several hoses going to one central contraption. one larger one from the top of the valve cover to the little contraption thing and from the contraption thing to the airbox.

 

What is the contraption for? Can I bypass it? My hose from the valve cover is broke on that hard plastic part and we have it hose clamped in place but wondering if I could just by-pass the whole contraption.

[bigalpha]

Well, I got the A/C working. It was a couple of disconnected wires going from the Compressor to the 'power center' area are.

 

I wonder why the PO disco'd them? If the compressor is bad, for whatever reason, can it be harmful to the truck if it locks up or quits working? The A/C blows pretty cool. I may get it recharged anyways.

[ocskipper]

 

not to hijack the thread but i just bought a comanche and if you look in this pic there are several hoses going to one central contraption. one larger one from the top of the valve cover to the little contraption thing and from the contraption thing to the airbox.

 

What is the contraption for? Can I bypass it? My hose from the valve cover is broke on that hard plastic part and we have it hose clamped in place but wondering if I could just by-pass the whole contraption.

 

The "contraption" is simply a connection for you vacuum lines. I had the same problem and removed the entire thing. It should just slide straight out of the clip and then you can reconnect the vacuum lines directly. :thumbsup: Huge difference once all those connections are zipped up tight and running right! Here is a pic of what I've got.

 

Before:

After:

 

Skip :USAflag:

[bigalpha]

Now the million dollar question. How do the vacuum hoses run? I haven't been able to find a diagram. I want to make sure it's all buttoned up.

 

I'm tracking down all the loose wires/unconnected connectors.

[ocskipper]

Now the million dollar question. How do the vacuum hoses run? I haven't been able to find a diagram. I want to make sure it's all buttoned up.

 

I'm tracking down all the loose wires/unconnected connectors.

 

I myself am still in the processs of figuring out all the mystery plugs, hoses, and connectors that are hanging out under the hood of the MJ. My Haynes manual has awesome diagrams that I havent gotten around to reading yet :nuts: but here is a link to the diagram that BLHTAZ posted.

 

http://www.comancheclub.com/forums/viewtopic.php?f=9&t=12517

[bigalpha]

Now the million dollar question. How do the vacuum hoses run? I haven't been able to find a diagram. I want to make sure it's all buttoned up.

 

I'm tracking down all the loose wires/unconnected connectors.

 

I myself am still in the processs of figuring out all the mystery plugs, hoses, and connectors that are hanging out under the hood of the MJ. My Haynes manual has awesome diagrams that I havent gotten around to reading yet :nuts: but here is a link to the diagram that BLHTAZ posted.

 

http://www.comancheclub.com/forums/viewtopic.php?f=9&t=12517

 

 

Thanks for the link. I've received some guidance (from a few people) that I should plug all the vacuum hoses except for MAP, CCV, and FPR lines. Whaddya think about that?

 

I found the source of my biggest oil leak, too. The stupid crimped connector between the hard and soft transmission lines. My XJ did it too, so at least I know how to fix it already. This thing is leaking bad, though. I can see 3 or 4 drops come squirting out.

Q5. Is the e-fan supposed to be wired to the ballast on the driver side of the fender? Mine is.

 

Q6. Here's another plug near the rear of the valve cover that doesn't have a matching side. Ideas?

[Pete M]

Q5. Is the e-fan supposed to be wired to the ballast on the driver side of the fender? Mine is.

 

got a photo of this? Maybe the previous owner did it out of ease-of-access-to-a-positive-wire?

[bigalpha]

Q5. Is the e-fan supposed to be wired to the ballast on the driver side of the fender? Mine is.

 

got a photo of this? Maybe the previous owner did it out of ease-of-access-to-a-positive-wire?

 

Sure. I'm pretty sure it's not factory wiring because it not only looks janky, but it's half-assed. MIght be hard to tell, but the positive wire coming off the fan plug is hooked to only one orange wire with electrical tape.

 

 

 

 

[Pete M]

Ok, so he wired it to be on with the ignition. Probably not the best way to have done that. :hmm: You can keep the current splice location (I'd re-do it properly though) if you want and use it to turn on a relay for the fan. The fan pulls a decent amount of juice and I would install a dedicated relay for it. :thumbsup:

[bigalpha]

Ok, so he wired it to be on with the ignition. Probably not the best way to have done that. :hmm: You can keep the current splice location (I'd re-do it properly though) if you want and use it to turn on a relay for the fan. The fan pulls a decent amount of juice and I would install a dedicated relay for it. :thumbsup:

 

I'd like it installed to OEM specs .. where it comes on with AC and when temp gets up. I don't want it on all the time; it's keeping my coolant too cool.

[Pete M]

I'm not sure that should be possible. :hmm: Unless you t-stat isn't closing fully.

[bigalpha]

Could be; there is evidence of recent t-stat work; clean bolt and lots of RTV. Maybe the PO took it out completely.

 

Now, the front end sprung some crazy @$$ leak. Not exactly sure the source, but it's the front bottom of the engine somewhere. Maybe behind a pulley. It's spraying out like crazy. I need to find it and fix it; it's losing a significant amt of oil.

[bigalpha]

I got the trans fluid leak fixed.

 

Now, there's a coolant leak. :fs1:

 

Q7. The hoses up top, that run to the pressure bottle and the heater core, they are crimped, so it looks like they are a one-piece replacement. Is this a dealer specific part, or can they be de-crimped?

 

reference: right above the oil dipstick.

[bigalpha]

Are the speedo cables from an 89 XJ the same length as the 88 MJ?

 

I'm assuming 'yes', but don't want to assume wrong.

[Pete M]

same drivetrains?