gogmorgo

Okay, I've been thinking about this all day after posting this morning and I think I've got this figured out. Check valves for compressed air should not be hard to track down, every truck with air brakes has them on the tanks to stop them blowing off if there's a supply leak. You'll need six of them, three T-fittings, and three pipes (or hose) fittings to adapt to the m14x1.25 spark plug holes. The idea is you pull the pushrods for both intake and exhaust on the rear (or front) three cylinders. Fish the lifters out as well. Leave the rockers on, pull them off, doesn't matter much. You've got two check valves on the T off each spark plug hole, sitting opposite so on each downstroke of the piston it pulls in through the intake check valve and on the upstroke pushes out the charge air check valve. You'll have an intake manifold of sorts to pull in filtered air, then an "exhaust" manifold for the compressed air, but it all goes through the spark plug hole. You'll get better compression if you pull the head and seal off the valves, but I wouldn't go that far until you've got proof of concept. My concern is it won't want to run on three cylinders. Dropping the front (or rear) half of cylinders pulls out every other normal power stroke. Firing order is 1-5-3-6-2-4 you'll notice that's the front three between the rear three firing. Convenient. Ignoring the engine's valves and using the spark plug hole and check valves means you get a compression stroke for every upward movement of the piston without needing to do anything fancy to the camshaft or exhaust manifold. Using the engine's valves to do that would require a custom double-lobe cam which will not be cheap when you don't even know if the thing's going to work. Doing it that way, not only are you losing 50% of the firing strokes, you're turning them into compression strokes, which doubles the work being done just to keep the engine running. A heavier flywheel will probably help, but again, cost. Not doubling up the compressor strokes and sticking with the four-stroke setup would mean pulling a vacuum on the former power stroke, which I think would harm the engine more than a second compression stroke. Another thing that might work that I just thought of, keep the "exhaust" blowing out the spark plug hole but eliminate the T and intake check valves. Instead use a super weak intake valve spring so the intake valve gets pulled open when the piston pulls a vacuum on the downstroke. I'm not positive that will work however. In theory the cylinder pressure will keep the valve closed, but I think you'll lose a fair amount of pressure before it closes with a weak spring. I don't think the exhaust manifold sealing surface will be good to retain compressed air, hence using the spark plug hole. The exhaust manifold is clamped on with bellville washers, which means that yes they hold tension, but it will only hold so much before they lift off, especially with only two per port. Arguably only one, because it's only held on by half of each washer (the other half holds on the intake). You're looking at getting 150(ish) PSI out of the system, but the stock exhaust system isn't going to see anything close to that. Maybe a tenth if it's completely plugged up. The exhaust/intake combo is notorious for having trouble sealing even before you put 150 psi behind it.

How's your crankcase vent system doing?

The custom ground cam would probably cost you more than a suitable compressor. If you want to do it cheap and easy, pop out the exhaust rockers and pushrods for cylinders 4,5, and 6, unplug their injectors, and thread a hose adapter into the respective spark plug holes. You'll need check valves for each of them. You'll only get a squeeze out of each piston every other revolution, and you'll definitely want an air dryer before it sees tools or anything. It'll definitely run like crap.

Yeah, if there's broken ceramic down in the cylinder you won't get it all without pulling the head.

If no one's called dibs on the gas tank skid yet, I'm interested. I just need it shipped about 2500 miles north and west... If I need to lay in something unpleasant at a junkyard I try to grab a floormat or carpet out of a minivan or bigger SUV. Don't know how well that would work for fire ants though, can't say I've ever had that problem, or any other crawlies. Usually just mud or snow. I'm also interested in the front skid but considering it's the same as an XJ I'm not super excited about paying to ship it.

My understanding is the two are interchangeable, although I've never done the swap, just debated using it in my MJ. The NV3550 has a lower first gear, but the rest are slightly taller (except 4th, both 1:1). I imagine you'd have to reclock the tcase or smash the floor or something to use a TJ version, same as the TJ and YJ ax15, unless you can find one out of an '01 XJ.

I'd just grab the sending units that came out of the XJ you pulled the cluster out of.

Diesel injectors are not cheap. Compression ratios are twice what gas engines see, and they don't just spray into the intake, they fire right into the compressed air mixture. Thousands of PSI. If you think the injectors are expensive, look up an injection pump. I also find it unlikely multiple injectors crapped out at once. The only thing I can think of that might cause that is contaminated fuel. Water, or maybe even gas. If it runs but just rough, it might be not a terrible fix, but if it's not running at all, that can be a pretty big deal with a diesel.

Well I guess I shouldn't complain too much about Fedex... I ordered everything Friday night, and package one showed up today (Monday) while my cousin was home for lunch. Fortunately he was home, because they just rang the doorbell, dumped the box on the front step (no porch, may as well just be on the sidewalk) and left. So maybe I should complain about Fedex?

Usually it's okay, I just have this tendency to live in the middle of nowhere. The last place I lived wasn't really an official town, and my post office was in the next town over. At least in Jasper I can put my PO box in the second address line and usually things will find me, but that wasn't really an option when the post office and street address are in different towns and one of them doesn't exist. We've got local smaller couriers who are very good, but when bringing stuff in from outside of the province, the big name couriers struggle a bit. But it makes sense I suppose. If you had five packages you got $15 a piece to deliver, how far out of the way would you want to pay someone go to deliver them? We're two hours at least and over 100 miles round trip from the next town over, and the next towns over aren't exactly huge metropoli either. The local businesses don't use the big names because the little guys are far more reliable, most people in town use the post office by default because they're the most reliable. If you live in the city everything's okay, I've never had a problem getting things shipped to city addresses. It's just out in the middle of nowhere in low population density areas that we have logistical issues like that.

If it makes you feel any better I'm only at 50% bumper on my MJs. And the one with a bumper is slowly having the missing rocker panels addressed.

If you can get it into the factory spot in the back of the head that would be best. It's a small hole though so it might be easier to adapt something to fit the sensor hole in the HO thermostat housing, which is where the ECU pulls it's reading. But you want it reading somewhere in the head. No other point will be as accurate, and if you put it in the radiator it won't react to a tstat stuck shut. If you've got permanent flow through the heater you can probably T it in there, but it won't be as accurate as the head, and it would be susceptible to a plugged or leaking heater core.

That's kinda what I thought. I was just surprised to see Pete had the exact same ones.

I just ordered a bunch of stuff from RockAuto that's shipping Fedex. I'm assuming (hoping) it's coming from the US because I'm paying duty on it. I messed around with some different shipping stuff (looking at maximizing what I can get from different locations). For bulkier and lighter stuff it seemed "post" was much cheaper, but for more dense packages Fedex and "post" were roughly equal in cost but FedEx promised a week vs almost a month for "post". I went fedex this time because I'm in a bigger city for school so I figure there's a good chance it'll show up. In the past fedex hasn't been terrible back home, probably better than most couriers, but I've had issues with some couriers not delivering. I live in a reasonably busy tourist town on the second busiest highway across Western Canada but it's about 200 miles to most of the couriers' nearest depot. I don't really know what all goes down, but it seems like a couple times a courier has attempted to deliver (or didn't bother) and left it at the depot for me to come get, 200 miles away, and just sorta assumed I would know to come get it, then sent it back to the shipper. I've also had couriers hand things off to the post office after refusing to take my PO Box number, but the post office won't deliver to my street address so it ends up going all the way back. If a shipper hasn't been communicative, I've got no idea what's going on or where it is, and it's too late by the time I realize it's been taking too long, so usually I try to default to snail mail to my PO box. It usually takes a while longer, but it just seems more reliable to me.

I'm not sure about that. The first gen Dakota bumper hooks around a bit at the ends, and the second gen has big plastic chunks on the bottom. The angle on the edge is opposite, as well. It also doesn't have the groove for that rubber trim insert. The centre section of that bumper looks very MJ, especially the reinforcement for the hitch, but the ends of it are wrong, the Comanche bumper is open at the ends and only covered off by the plastic trim piece. The S10 and Ranger bumpers have wider rubber trim strips on them, and I don't see rubber strips on any of the Japanese trucks.

I don't know how much load I'd want to add to the stock shock mounts. It's just a stud mounted in single-shear at either end. I'd look at getting a small airbag to replace the bump stop.

I've done it at the side of the road. As long as you're around 1/3 tank or less you'll be fine, no need to drop it. I didn't pull the driveshaft but I can see how it might improve access.

This is what came with my '91 when I bought it. With such high mileage it's hard to imagine it's original but you never know. It has been repaired somewhat, albeit questionably. This is an 89 (I think) in a wrecking yard. And this is the bumper I pulled off a '92 in a wrecking yard: Interesting to note the differences. There's also a round vs square license plate light thing. I assumed my first bumper's lights were just aftermarket tacked on but Pete's first post with the trim has the same ones?

I may or may not have the Sex Pistols about 20dB louder than normal in my ZJ right now...

I once put some cheap vodka in my Lada's washer fluid bottle for the lols. It doesn't really clean the windshield that well. It wasn't awful, just kinda streaky. I've also debated trying to use the washer fluid reservoir as an fuel dispenser for a carbed truck that had a mechanical fuel pump fail just to get it back onto a highway (at least into cell service), but just as we decided to go for it someone happened to drive by and we caught a ride to a parts store and back.

I mean it kinda makes sense. Everything is further apart and there's less stuff going.

I do most of my browsing on mobile and usually default to desktop mode on most sites. Maybe it's just me but most of the mobile sites kinda suck to use. I kinda get wanting to save on bandwidth and small screens sometimes need different visual formats, but it's not 2007 anymore. For the most part the only things I can't render on my phone are Flash-based, and again, it's not 2007 anymore, I rarely if ever encounter Flash. Not being able to access all the features of a site is more frustrating to me than whatever issue it is the mobile site was trying to solve. And this is coming from someone still running ios9.

Kinda late now, hopefully you made it to school. I would also say it sounds fuel related. Spark problems are usually an all or nothing sort of deal, either it runs or it doesn't. First thing I would do at the side of the road is bypass the fuel pump ballast resistor. If that fixes it, Bob's your auntie, either replace it or leave it bypassed, up to you. Failing that I'd look at fuel pressure, like Minuit says. Depressing the schraeder valve only tells you there's some pressure, it doesn't tell you it's enough pressure. For that you need a gauge.

If you're having traction problems on just wet pavement you probably should get some new tires... My 2wd five-speed does not have that problem, and I live in a place that looks like this half the year: Honestly I prefer the five-speed in this sort of weather. Climbing hills it's not likely to downshift when I don't want it to, which I find is more likely to cause me to lose traction than when I'm shifting on my own. An automatic won't downshift unless it's under power, which is what causes you to spin out. A manual trans on the other hand you can match road and engine speed and slip into the next gear down without needing to be on the throttle, and you control the reengagement of the clutch... if you even used it.