ParadiseMJ

How did he come to that conclusion. Did he just put it in R and nothing happened? I was told my tranny was shot...needed a torque converter...$210.00

I think that's more of a "burn" mark from the heat of the lamp. You could probably reach in with a bit of sandpaper or steel wool and maybe buff it out. There are a few write-ups on separating the front plastic from the back. BTW: an LED back-up lamp will light it up without the heat.

It connects on the other end. It is a vent line. If you look straight down along/on the inner fender you'll find 4 steel lines and a little plastic plug/clip type connector. Those lines connect to the four steel lines. Then the steel lines follow the inner fender and come out by the front axle, turning back in to color coded lines (in a wire loom). Then if you go back to the transfer case, there is a big plug on the driver's side of the case. the four lines plug into that. Somewhere along the way (and I forget now since I eliminated the vacuum axle and swapped in a 94 t-case and removed all those lines) the vacuum lines plug into the 4wd actuator on the front axle. So, just to be clear, that blue line is just a vent, not covered. The thingy on the tip LOOKS like it should be connected, but no. It's a one way check valve so air goes one way in or out to the air. Any vacuum line that has one of those on the end is just that. A vacuum line with nothing on the end is just sucking air. The Renix vacuum system goes like so: The vacuum SOURCE is on the intake manifold. It crosses over the engine along the firewall, along the passenger fender and dives under the battery tray to the vacuum reservoir. The reservoir "saves up" vacuum (when you're off the pedal, going downhill etc.) for when it's not being created (aka when you're accelerating, going up a hill etc). That way you have vacuum to run your HVAC and cruise, consistently. So that's the fat line. The skinny line FROM the vacuum reservoir connects to your Acessories (cruise, heater valve, blend doors) Just the one black line supplies vacuum to the plastic "vacuum manifold" behind your heater controls in the dash. NO vacuum and all the blend doors default to DEFROST. So just a small leak, a crack, a break, a rub, will sap your vacuum...and it might work some of the time. A completely disconnected or broken line, non of that stuff will work, especially when you are accelerating. Make sense?? Now, that is the passenger side vacuum system. The engine side vacuum has almost ZERO to do with the HVAC side other than the intake manifold SOURCE line. The ENGINE side vacuum is borne in the intake/airbox and throttle body. A disconnected/broken line there will affect your fuel pressure regulator, CCV system, EGR, MAP and your Jeep will run like crap, if at all sometimes.

The white, blue, yellow, red are bundled for the vacuum lines for the front axle/transfer case. On the blue line, there is a check valve (the little UFO looking thing), that one should not have a cap on it as Keyav8r says.. These lines have nothing to do with HVAC or cruise. But as Keyav8r says, the pink and black wires coming out of the firewall have everything to do with HVAC and cruise. Look at the black line and follow it under the battery tray, all the way to the vacuum reservoir behind the bumper (P) side. A common area for a break or rub or being eaten by battery acid. Bulk vacuum line is cheap, and cheap insurance to keep things working right. You also may be right that you upset something behind the dash. There is a plastic vacuum "manifold" behind the heater controls that can come loose if it gets bumped or pulled on...it's where the other end of the pink and black lines going through the firewall end up The lines on the passenger side are all for running accessories...cruise, HVAC, t-case, CAD, heater. They really don't affect on the running or driveability of the Jeep. So it can have a vacuum leak and run fine.

No, the yard I'm talking about is in Oroville. Oroville Self-Serv Not a specific "Jeep" yard, but they've always had a bunch of XJ's and always 1 or 2 MJ's in their stock. Lot's of older Jeeps that come out of the hills around here. The guy says he "can't make a go of it anymore" but I think he's just retiring, who know's, they're always busy but may be too cheap. Back to the important stuff, what Norcal Jeep pick n pull is closing? I have tomorrow off and plan to go to the junkyards

Depending on the actual part...or type of part, I usually buy at NAPA. For a water pump, always new, never a re-man. I put a re-man alternator in my wife's Camry, 5 years ago...and had to replace on warranty. Then I put a re-man alternator in my commuter Nissan, only having to replace it 3 months later. Warrantied also. So sometimes NAPA is a crap shoot too. I won't buy most electrical stuff at AutoZone, O'Reilly's etc. But I will buy a Bosch fuel pump there or a Timken Unit bearing. Usually NAPA (WIX) for filters. NOS only on ebay. If I'm buying from RockAuto they usually have a variety (of manufacturers) for the same part at widely differing prices, and sometimes they just don't have it at all. On a sad note, the best damn Jeep pick n' pull in Northern CA is closing forever at the end of the month. So I'll be buying a lot from them next week, since most of my MJ is built with "junk".

I thought of possible flooding, a stuck injector etc. which is why I tromped the pedal, which did help a little. The O2 is only a couple years old. The problem has been around for a year or so but it's so intermittent that I forget about it...until it happens again :doh: I dunno. :dunno: Don't have time to mess with it this week. I get truck time this weekend. Test the O2 ... key on or key off?? What's the O2 thread size if I wanted to plug it temporarily. I DO have a cracked...kinda ruined knock sensor, too. TIA guys.

The title is what my truck (88 MJ 4.0 AW4, 4x4) sounds like under the following conditions: Long drive (1/2 hour) at speed, stopping, then starting it up again within a few minutes. Short drive around town when the engine is all warmed up, then starting again within a few minutes Long drive (1 1/2 hours) at speed, then slow drive for another 20, then idling, Then turn off, and restart within a few minutes. If it sits for an hour and it cools off a bit, it doesn't do it, it'll fire right up and purr like a kitten. This ONLY happens every once in a while, like a couple times, every 3 months or so, then it clears up and runs like a friggin' champ. When it's doing the putt, putt, putt thing...if I give it gas it dies. If I put it in Neutral it tends to even out after a few putts. If I tromp on the gas pedal after the first incident of putting, and re-start it, starts right up and it's smooth. Any ideas?

I finally got a new set. $32 shipped. As usual, it took an hour to do the first door, 20 minutes for the other.

That is your A/C condenser. It doesn't take tranny fluid. You're missing the A/C lines. The tranny fill pipe has a dipstick. You might want to find the tranny dipstick and check the fluid level. Don't know if you can save the condenser...or if it just cleaned it out real good. If it's a 4x4 rig, make sure the transfer case isn't in Neutral.

$20 a pop at our local yard, so I picked up a pair. They were oxidized, but brought back to almost perfect with a little 240 wet/dry sandpaper and some Testor's model paint. I'd sell them, but I won't cause I may need one or two and I can't afford to buy them on Ebay for $100 each or more.

Just in case you don't have this : http://www.bteventures.com//mj1988electricalmanual.pdf ..and if you're fuzzy on using a digital volt meter this is a good tutorial. required reading for a Renix. https://www.youtube.com/watch?v=bF3OyQ3HwfU The #1 tip on using the meter, for me, is to make sure the switch is OFF when you're done, or the next time you use it, it'll be dead. :doh:

Things to look at: Is your defrost mode on? Or A/C ? Is the compressor cycling? Clean or replace IAC? TPS adjusted properly? Sensor grounds updated? Does it bottom out on "power" when driving, like a clogged cat might?

Apparently so...I was naïve...for an old geezer.

If you've done all that and it's still getting hot at speed...and...if you have not swapped out the radiator, I'd vote new radiator. I resisted advice that my radiator was shot, did everything else, no change. After all, I had a three year old CSF 2 row all metal radiator with only about 20K miles on it, it couldn't be bad. Bought a Spectra OE replacement radiator, plastic tanks, plastic petcock, new cap and all. For $110. Never had another problem with cooling. 2 years now. P.S. I bought the CSF from radiator barn and tried to cash in on the warranty...but the warranty is no good if the place is out of business.

Sounds like you fixed the problem. Side: When I first swapped the bench for buckets I unknowingly got some rocker bases. I am not a BIG guy. Like 5'11" 185# The rockers were intolerable. I felt like Herman Munster in a Miata with the top up !!

Are your seats actual MJ buckets or did you have to modify XJ (or another vehicle) buckets. I ask because my bud had to modify his XJ buckets to fold forward and in doing so, screwed up the recline option.

Me too!

I don't think I'd be comfortable calling it good just by wiggling every cable each time I had an issue. Also, things that make your truck die all of a sudden don't usually solve themselves for very long. Some actual diagnoses might be in order here. Do you have a volt meter...a Digital Volt Meter (DMM) to test circuits? That said, what does it do when you turn the key? Nothing? Or does it try to start, but just won't catch? There are not that many variables. AKA when you turn the key does it turn the engine? Do you just get nothin' or does it crank and crank and crank, but doesn't fire, start? If it doesn't turn at all, I'd be looking at battery cables and connections, like take them off, shine them up and put them back on, securely and try again...don't just "feely" them and call it good...make SURE. If it turns and turns but doesn't start it's most likely that you CPS is toast, like Pete says. The CPS (CKPS) or Crank Position Sensor gets it signal from the flywheel/flex plate as it turns, if it's toast (which is what it sounds like) you'll get NO spark. Replacing it is a b**tch if you've never done it, but it's easy if you have done it a few times. 2 hours or 15 minutes. Depends on your experience level.

I thought of that but the lock cylinder on the passenger side is broken...due to some dip stick trying to pry it, like with a screwdriver, it's not just un-key'd, it's wallowed out due to the screwdriver action, Even the original key won't go in. Also, the driver's side just spins and spins and I figured buying new locks (even at $35 a pair) would be cheaper than going to a locksmith...around here anyway. Just to re-key our old house (4 outside doors) cost us $220. :eek:

That is, in fact, where it goes...but...when it's tucked away in the bumper, a few things can happen to it. The vacuum lines can be near to and susceptible to battery acid, thereby corroding and rendering them useless (and making it hard to track down leaks). A little fender (bumper) bender can crack the ball (and you may never know it). It's a PITA to get to and if you have an HVAC issue (seeing as how this area is where leaks most often occur) that's usually where the problem is. I have mine relocated up in to the engine bay...kind if like this only actually INSTALLED, screwed down. I only have about 18" of vac line running to it. It doesn't take up any space and I can always get to it. Also, since I have an aftermarket bumper, installing it behind the bumper is problematic.

Neither one of my door locks work. I went to O'reilly's and bought a door lock kit. Got in to the door, removed the locks, went about replacing them until I noticed they were not anything like the one's I had removed. Returned them. Went to NAPA, they brought out the same locks. Both sets looked like they had a Chrysler key included. Double sided. I told them my old key looked like a GM key so we went about looking for a AMC compatible set. Hmmm, then I looked online and found the right ones (or at least the picture looked right). Only after I looked at "Jeep door lock set", instead of "Jeep Comanche", and it was specified for a "Wrangler" So my actual non-tech question, does the CC or even NAXJA vendors list have a code for $$ off at, say 4x4 parts.com,RockAuto, or any other vendor, the set for the newer set was $18, the set for "Wrangler" is $38 Thanks

Have you replaced any sockets, this particular socket? I had to replace 2 sockets on my 88. Don't know where you're from but I live out west and I have very little, if any rust or corrosion on my rig....but the sockets were toast...that and cutting splices and soldering my trailer wiring fixed all my lighting my issues

That particular vac line comes with the whole front vacuum harness, but like Dirty said...you can just go to NAPA buy a foot of bulk vac line and two elbows...will cost about $3.00. Note: take the old line and elbows with you tor size...specify that you just want the elbows and a piece of vac line. if they look it up in the computer you'll end up spending $20+ for the whole front harness