Eagle

I hope you get it fixed.

They do offer a street legal version, but it won't come to the U.S. because it doesn't meet our safety standards.

I have a 2000 XJ FSM. Don't know if the colors are the same. Black is ground. Black to black is a good guess. It shows me DG/WT (dark green/white?) all the way from the tank module to the fuel pump relay in the power distribution center, through two connectors. 18 gauge It shows me BR/YL all the way from the tank to the power train control module (PCM), through three connectors. 20 gauge It shows me DB/LG (Dark blue/Light green?) out of the tank all the way to the PCM, through one sensor. 20 gauge. Sorry I can't help more. Colors match on the frame side, but don't match up for the tank side. You're probably good to connect blue/green to blue/green and black to black, but you're on your own for the other two. Best I can offer is that one's 18 gauge and the other's 20 gauge, so try matching by wire size.

You might have to turn on the street, too.

Someone just recently posted a similar discussion. His issue, after messing with CPS replacements, turned out to be the distributor sensor. Found it:

Found this in Youtube. It's a hack for an open-end wrench that may make it possible to work on bolts or nuts that have rusted so they won't quite fit any standard wrench size.

Look, Mate -- I'm trying to help you. If you don't want help, I'll move on to someone who appreciates my efforts.

Sorry to answer with a question but, before considering a response -- is your proportioning valve intact, with the connecting link down to the differential? Is the arm on the valve basically horizontal? I ask because, if the entire mechanism isn't there, the valve itself can't function as designed.

That's normal when starting up an incline ... but that's useless for determining if your torque converter is locking up or not. I don't know how you can say it's trying harder than it should if this is your first Cherokee. You have nothing to compare it against. I bought an '88 XJ new in 1988. Mine's a 5-speed. Of course, mine has 3.07 gears, but my overall final drive ratio on stock tires s probably close to yours on 33-inch tires. And the '88 will not go up hills in 5th gear, not even on interstates.

Thanks, I forgot about that difference. My numbers are for the .75:1 overdrive ratio.

Do the RPMs drop with the speed staying constant, or does the speed drop too? You have to give it more gas than you think you should because you're operating below the torque peak of the engine. You don't have the proper gears for those tires.

First you have to know how fast you are actually going. Then correlate that to engine RPM. An automatic transmission is based on a fluid connection between the engine and the driveshaft(s). There is slippage, so the engine speed isn't always constant relative to the road speed. That leads to inefficiency, so in the 1970s the manufacturers started making torque converters that lock up. Once the converter is locked, then there is a constant relationship between engine speed and road speed. The way you can tell is if the engine RPM isn't correct for the road speed but, to figure that out, you have to know how fast you should be going for a particular engine RPM (or what the engine RPM should be for a particular road speed). For 33-inch tires, with 3.54 gears in 4th (overdrive), the engine should be turning 1830 RPM (plus or minus about 10 RPM) at 65 MPH. But that's 65 actual miles per hour -- if you don't have the correct speedometer drive gear installed, you can't go by the speedometer. You could use a GPS -- your cell phone app may be accurate enough. Remember, speedometer error isn't a constant speed difference. If it's off by 10 at 60, it's only off by 5 at 30. If it's off by 10 at 30, then it's off by 20 at 60. Knowing your actual speed-to-RPM relationship will tell you whether or not you have the correct speedo gear, but probably you don't. If you find that the engine RPM varies even if the road speed stays the same, that's a clue that the torque converter isn't locking up. Also, if the engine RPM is higher than it should be for the road speed, the converter my not be locking.

On 33-inch tires, in overdrive 2200 RPM would be approximately 78 MPH, not 65. However, 2200 RPM on stock tires would be about 68 MPH. Have you checked your speedometer to see if it's reading accurately? If the speedometer drive gear wasn't changed when the big tires were installed, the vehicle will be going a LOT faster than what the speedometer indicates. Considering that 2200 RPM is barely above the torque peak for the '87 Renix, and below the 2400 RPM torque peak for the '88-'90 Renix, I wouldn't consider running at 2200 RPM to be "working hard" or "overworked." For these engines, I consider gearing to run about 3,000 RPM at 70 MPH to be optimum for OEM tires, and less than optimum for larger, heavier tires. One other thing to consider -- do you know if your torque converter is locking up as it's supposed to?

Kyle, if your Jeep still has the factory axle ratio (3.54), those 33-inch tires are killing you in the gas mileage department. The Cherokee is basically a brick on wheels at best, and gas mileage goes down quickly as speeds increase. I did a test once with a brand new 1999 Grand Cherokee. I drove from Connecticut to Pittsburch, PA, for a job interview. On the way out, I drove at 65 and 70 MPH. On the way back, as an experiment, I very strictly limited myself to a top speed of 60 MPH just to see what difference it might make. It did make a difference. IIRC, the gas mileage was 3 or 4 MPG better when I kept the top speed to 60 or less. For any internal combustion engine, the most efficient engine speed is the speed that produces the peak torque. In an automobile, this isn't directly reated to speed because drag increases with road speed so at higher speeds you need more power just to overcome resistance, but a good rule of thumb for street driving is to gear so that your highway cruise falls on the engine's torque peak. You have an '87 4.0L. The torque peak for your engine is 2,000 RPM. With your 33-inch tires, at 65 MPH in overdrive your engine is running at around 1800 RPM -- below the torque peak. At speeds below 65 but fast enough to put you in overdrive, you're even farther below the torque peak. That means when with the O2 sensor functioning, you're never giving the engine a chance to work at best efficiency. With those tires, you'd be much better off with 4.10 or even 4.56 gears.

2000. I think the 1999 Grands got the coil-on-rail ignition, but the XJ didn't get it until 2000.

FWIW, the Renix 4.0L engine generally produces better gas mileage than the HO. I own an '87 MJ 4.0L, an '88 XJ 4.0L and an '88 MJ 4.0L, a 2000 XJ 4.0L 5-speed and a 2000 XJ 4.0L auto. The '88s get better mileage. The 2000 XJ auto gets around 16 MPG in mixed driving. The '88 MJ was getting around 18 to 19 when I used it regularly, the '88 XJ gets 18 to 20 MPG and has delivered a best-ever of 28 MPG on a weekend trip from Connecticut to Vermont, loaded down with a lady friend, two kids, and gear for a long weekend. Unless your injectors are massively oversized, it shouldn't be running rich. The O2 sensor controls the duty cycle of the injectors to keep the mixture in the optimum range. When did you last replace the O2 sensor? When it fails, the ECU goes into open loop mode and defaults to a rich mixture because it thinks the engine is still warming up. This could also happen if the ECU temp sensor (the one on the side of the block, not the one at the rear of the head) is bad.

Yeah, I know. I have no idea how much longer Old Faithful can last, but I doubt it'll be more than another year or two. I would like to make 300,000 miles (it's now at 287,000). I really didn't want to sink any more money into it, but I remember that the Renix-era injectors are known for separating between the metal and plastic body, so I girded my loins and ordered a set off Amazon. Which means I can't get it running this weekend.

My '88 XJ has been off the road since my wife died four years ago. Now that the snow has receded, I was able to get underneath and patch the fuel leak -- I thought it was a gas line, turned out to be the metal fuel filter had rusted through. Got that all fixed, tried to start it this morning -- and all six injectors are leaking. What's a good source for injector O-rings?

My '88 4.0L MJ is almost that bad (not quite). I'm still considering options. I don't plan to use mine for off-road any more, and I don't plan on tires larger than 235/75R15s or possibly 30s, so I'm seriously considering grafting on the rear quarters from a 2-door XJ. The wheel arches will be a little smaller than proper MJ arches, but I think it will be easier to hide the carnage that way.

Are you talking about a 5-speed with a floor shift, or an automatic with a column shift? For 5-speeds, the only MJ I've ever seen with a straight(-ish) shifter is my '88, and it's because it has a tranny and shifter out of a Wrangler.

There was -- used on all 1987-1/2 thru 1990 XJs and MJs that didn't have cruise.

Great idea. I was thinking about Nylocks -- castle nuts never occurred to me.

It worked. When Chrysler took over, they immediately started looking for ways to save pennies, so they eliminated anything they thought they could get away with[out].

Doesn't someone offer a reinforcement plate for the "frame rail" where the track bar bracket mounts? I would look for that, and use Loctite on the bolts.

If the lights work (correctly), they have a ground. Keep in mind that if there is a bad ground, one circuit/filament may seek a ground by back-feeding through the other filament. That's when you start seeing funky behavior from the lights.