ParadiseMJ

I've had a K&N cone filter on my XJ for years, Never had a problem with smoggers. I gave Jeep to my son last year, he tried to smog it, but it failed because it needed an O2 sensor...it failed with high numbers...they tagged it as a "gross polluter" and so they take the smog AND engine inspection to a higher level. Because of the lack of an air box, it also failed that part of the inspection. We put the box old back on, with all the appropriate vac lines. Surprisingly, it didn't affect anything...except he got less noise. Not super noticeable while driving, but under the hood it was much quieter. After seeing this I'll be looking for another airbox for the MJ. I never thought the cone filter did that much good anyway.

X2 on this. Vacuum lines are MUCH cheaper than gas. Get the proper, or at least SOUND vacuum tubing. One whole solid piece, not repaired...replaced. You can even get a MAP sensor at the junkyard for a song.You should be getting at least 250 miles on a tank IMHO. I see tons of sketchy and missing vacuum configurations in the junkyards. Buy the correct harnesses where you need to, and the rest of the vac lines can be just bulk line...like 75 cents or $1 a foot. Taped up and/or spliced lines are invitations for leaks, ergo poor performance...and bad mpg.

Going to be replacing my head gasket this week. Any insight on which way I should go? Just pull the head and if it's not cracked, warped or valves look funky should I : Just plop the old head back on? Send it to a machine shop ? Replace the head with a re-man ? What's the typical cost to have the head machined/magnafluxed only...since I've never had to do a head.

I needed a spring compressor for my XJ and MJ. I suppose I could have done it without but I did not want to take everything off. Just made it easier for me.

I've seen trucks with the front higher than the rear and said "why?"....I've also said "that looks lame". To each his own but you asked if it would look good...I say no, I personally like the stock rake on the MJ.

First Xmas tree run this is November in the Sierras @ 6K elevation...usually 4-5 ft of snow...where the bleep is the snow.

Have you crawled under the Jeep to make sure the transfer case linkage is attached properly? The dash light is operated by a vacuum switch (located on the passenger side fender, by the firewall...it's blue. When the lever is pulled, into 4HI OR 4LO, considering the linkage is attached and adjusted properly, the transfer case switch opens and sends vacuum to the dash light vacuum switch and trips the switch...turning the light on. If you're having trouble with the brake lights: check to see if the brake light switch is firmly attached. Check to see if you have trailer wiring, funky trailer wiring

Yep, it's got the R stamped on the impeller....and the "scoops"are on the reverse edge Just like my XJ...same P/N. XJ runs cool. Belt routed on the smooth side. When I give it throttle with the cap off, the coolant level drops as opposed to spews out. Thanks though.

If I'm having a problem with a stock item, I usually replace it with a stock item, unless it's a viable upgrade. A bigger fuel pump won't solve your problem. Fixing the stock system properly will serve you better than "running a jumper wire". A stock pump should supply the right amount of pressure if it's got the right amount of voltage. I'd say your problem lies in the wiring, not the pump.

My thought exactly. I don't know how else I'd get so much air OUT of the radiator when I run it with the cap off. I've flushed the block/system twice (once with a "quick flush" and once with a full chemical flush) and filled it with coolant twice. The coolant is sparkling clean. It's a Bosch pump...and it is working after doing the below test AND pulling the heater hose to see if I was getting a good flow. It started well after I swapped the tranny. Like a year later. It ran fine all last summer and all winter with the AW4 in there. The pump seems to be working fine. In addition to the test you posted I pulled the heater hose, at the core inlet. Got a good steady flow from the hose via the pump. Also, with the cap off, the coolant level drops a good bit with any revving. The aeration test...once the engine is up to temp, and above, it bubbles steadily. My quandry is that with the absence of a head gasket leak (or theexhaust gases in the coolant test) how is air getting in there other than being INJECTED in by a head gasket leak?? Seems to me that I have exhausted all my avenues other than pulling the head and taking a look. Sorry to keep hammering on this issue, but I feel I've done everything I could possibly do, with the exception of the head (and I don't wanna do the head). seems I just have to bite the bullet. I think a shop would have already done the head after charging me for all the diagnostics first. I had a very similar issue on my Nissan, it passed all the tests, but replacing the gasket fixed it...so, here I go!! Unless, of course, there are any last ditch tidbits of knowledge out there.

OK fellas...I'm officially desperate. Still struggling with cooling system FUBAR. When engine heats up and t-stat (new 195 stant) opens it starts blowing coolant out the overflow at idle OR at RPM's. ALL the cooling components are less than 3K miles or newer. 2 row CSF all metal radiator...1988 4.0L converted to open system...3K miles ago. I don't have a heater valve, I deleted it when I did the conversion. I know you've heard this all before, but I can't drive my truck anywhere without it getting HOT and blowing coolant. WTH?? I have tested: New catalytic converter, new exhaust manifold, new gasket & flange donut. compression - good (great actually) 119-124 within 5 psi across the board. No adjacent discrepancies. No water in oil, no oil in water NO driveability issues. Idles smooth at ~700-800 exhaust gases (block tester) - none - tested it 4 times, with different fluid each time heater core - clear - no rust, crud, junk or small animals radiator pressure - holds pressure at 20 psi overnight - good, no leaks. cap - new 16 lb. - holds pressure @16 lbs for a couple of hours (the longest I've let it go) all hoses - no leaks - spring in lower hose ZJ HD fan clutch coolant QUALTY...it's new, and it's fine. 50/50 Prestone Green (ethelyne glycol) and distilled water. air bled from system...4 or 5 times and each time I have had to replace coolant. How do I test for a.) a bad pump (it's not leaking, wobbling and the belt is good AND yes it's a reverse rotation with the belt routed properly) or b.) a blocked radiator before I drop the $$ on either. OR is there something else I am STILL overlooking??? Help me Obi-Wan Kenobi...you're my only hope.

I found the article. He did an AW4 into a TJ, but the principle is the same...scroll down to "More AW4 swap" 6 pages I think, to the part where he's doing the linkage modification for the TC. http://www.stu-offroad.com/engine/aw-4/aw-4-11.htm

When I did the same swap I had to snag the linkage bracket for the AW4. IIRC the TC linkage pivot was built right in to the BA-10. Since the AW4 is longer, I had to move the body side pivot back about an inch...was not that hard to do as you're only drilling in to the body sheet metal to line up the body side pivot up with the tranny side pivot. I have a picture of it from Stu's Offroad tranny swap page...but it's on my work computer...I'm on vacation til next week.

I like my Sashquash sautéed in a little butter and garlic!! I just pick the hair out of my teeth later.

The pressure built slowly, but since I didn't have a pressure cap on it (I had the tester on it) it kept building. I get that part. The tester instructions said to turn the engine off before the pressure got to 30 psi. So, if the cap let go at 16, it would have never gotten to 25-30...it'd just blow the pressure...and coolant into the overflow...right !!?

It's been overheating and blowing coolant out the overflow, and although I did test the cap, it was somewhat inconclusive. The adapter for the tester was (looked) identical on either end. When I tested it one way it held solid pressure for 5+ minutes or so, when I flipped it around, it lost pressure immediately, down to about 10 psi. When I hooked pressure tester to the radiator and ran the engine, the pressure began rising up 20-25 +. I had asked if the cap generally relieves the pressure a bit at a time, but it seems like it was just continually blowing coolant one it got past 210...and up. If the system is over pressurizing...why? If it's just a faulty cap, I get it. Where do I find a decent cap? This one is a month old...the one before that was 3-4 months old. The SAME make cap on my XJ has worked fine for 2+ years. It's a Stant from NAPA..not a Chinese special from AZone

Got another gauge... a little more encouraging news...cold engine...WOT...dry...rad cap off. Cps disconnected. 1 - 118 2 - 121 3 - 120 4 - 119 5 - 120 6 - 121 Those look like good numbers to me, and more what I expected. 1988 4.0 with 190K on the clock. But it still leaves me in a quandary as to why my cooling system is (seems to be) over pressurizing. Any ideas? I'll do another test later with the engine at temp...with a drop or two of oil in each hole. Should I expect the numbers to increase or decrease...or change drastically ?

Now THAT's funny...especially coming from an Oregonian!! ...but seriously folks...Oregon, for the most part, is a very scenic place.

No, I HAD a BA-10...I put in an AW4....but all the swapping of wiring...88 to 94 has been a little problematic. Brackets, cables etc. It would have been a lot easier just finding an AX-15 and done it properly. If I ever get another MJ (or XJ) with the same configuration that's exactly what I'll do.

I swapped in an AW4 for a BA-10. In retrospect I shoulda don an AX-15 (with an EXTERNAL slave). More power, easier to gear down on a steep slope, less problems

That was my plan this afternoon... if the numbers don't change at all I'll be fairly sure that the tester is at fault. Then it's back to the drawing board.

Yep! ..as I remember the old school tester had a Schrader valve thingy to release/reset the pressure.

In the quest to solve my overheating problem I’m doing a compression test. WTF am I doing wrong?? It’s been awhile since I’ve used a compression gauge…I had a handheld tester that you just hold up to the plug hole…the tip was rubber…you just jammed it in there and have someone crank the engine a couple times. Boom, instant result. Accurate too. The tester I “borrowed” from AZone is the screw in variety which everyone uses. The instructions say “remove all spark plugs, set at WOT. Remove the coil wire, screw in the tester nozzle, crank engine, repeat for all cylinders. I did just that. The results I get say exactly 90 psi across the board…all 6, no variation. Since the truck runs and idles fine, doesn’t smoke, and has power…I’m thinking the results are in error. What am I doing wrong or is my truck so f***ed up that for some reason ALL my cylinders are running at exactly 90 psi??

Nevermind

...and which of us doesn't suffer from the same...I know I do, which is why I'm always either nursing my back, my leg, my arm and usually have a bandage, tape, a brace, and/or burn cream ON...not just ready, but in use. Hope he's back in business soon.